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Factor structure and validation of the Obsessive Compulsive Inventory-Revised (OCI-R) in a
Greek non-clinical sample
Ioannis Angelakis1-2* Maria Panagioti 3 & Jennifer L. Austin2
1Panteion University, Athens, Greece;
2University of South Wales, School of Psychology, Pontypridd, Wales, UK;
3Institute of Population Health, University of Manchester, UK
RUNNING HEAD: FACTOR STRUCTURE AND VALIDATION OF A
HELLENIC VERSION OF OCI-R
*Correspondence: Dr Ioannis Angelakis, University of South Wales, School of Psychology,
Pontypridd, Wales, CF37 1DL, e-mail: [email protected]
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Abstract
This study assessed and validated a Greek version of the Obsessive-Compulsive Inventory-Revised
(OCI-R) in a large community sample. A total of 1379 Greek adults, including university students
and individuals from the community, participated. Overall, the Greek OCI-R supported the six-
factor solution, namely checking, ordering, obsessing, hoarding, washing and neutralizing, which
was suggested by the original scale development and was later confirmed in other cultural settings.
OCI-R was found to have very good to excellent psychometric properties as demonstrated by the
application of traditional and alternative validating methods. Further, a five-factor structure that
excluded the hoarding scale provided a slightly better conceptual fit of the data. In light of new
recommendations, the Greek version of OCI-R provides compelling evidence of its efficacy to
clearly differentiated between high- and low self-reports of OCD symptoms. We discuss that scores
from the Greek community sample were commensurate with those observed in clinical samples.
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Factor structure and validation of the Obsessive Compulsive Inventory-Revised (OCI-R) in a Greek
non-clinical sample
Obsessive-Compulsive Disorder (OCD) is a disabling mental health illness characterized by
recurrent intrusive thoughts and repetitive covert or overt acts, namely obsessions and compulsions,
which elicit a considerable degree of discomfort to the sufferer (American Psychiatric Association,
2000, 2013). OCD has been described as a highly heterogeneous disorder, which makes its clinical
presentation and subsequent treatment difficult to understand and manage (Lochner & Stein, 2006;
Mataix-Cols, Rosario-Campos, & Leckman, 2005). Recently, it was removed from the anxiety
disorders chapter to compose a new clinical entity of obsessive-compulsive and related disorders
according to DSM-5 (American Psychiatric Association, 2013). OCD shares some common
characteristics with a number of other clinical syndromes, such as Body Dysmorphic disorder
(BDD) and Hoarding disorder (HD), which now are reflected in the diagnostic criteria for these
disorders. However, the unique features of each of these conditions still allow their classification as
separate mental disorders. Although changes to the criteria and methodological limitations (e.g.,
Angst et al., 2004; Gibbs, 1996) render an estimate of its prevalence difficult, epidemiological
studies suggest that the lifetime OCD prevalence varies from 1.5% to 3.5% (Angst et al., 2004;
Crino, Slade, & Andrews, 2005; Subramaniam, Abdin, Vaingankar, & Chong, 2012), whereas
28.2% of the general population report OCD symptoms at least once in their lifetime (Ruscio, Stein,
Chiu, & Kessler, 2010).
Numerous studies highlight the distress and apprehension that obsessions and compulsions
cause to people with OCD (e.g., Veale & Roberts, 2014). Further, OCD is associated with great
reductions in quality of life and severe impairments in social and occupational functioning (Bobes,
Gonzalez, Bascaran, Arango, Saiz, & Bousono, 2001; Subramaniam, Soh, Vaingankar, Picco, &
Chong, 2013). Consequently, a number of self-report measures have been developed to diagnose
OCD and to assess the frequency and severity of OCD symptoms. The most well-known of these
measures is the Obsessive-Compulsive Inventory - Revised (OCI-R), which was developed to
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assess the full dimensions of OCD symptoms and their severity, as well as the overall distress
caused from these experiences (Foa, et al., 2002).
OCI-R is a shortened version of the Obsessive-Compulsive Inventory (OCI) (Foa, Kozak,
Salkovskis, Coles, & Amir, 1998). The main advantage of OCI-R is that it requires less time to be
completed than the original OCI. In comparison to the 42-item structure of OCI, OCI-R consists of
only 18 items, which measure symptom severity on a 5-point Likert-type scale and form six sub-
scales of the most common symptom categories encountered in OCD patients, including a washing,
checking, ordering, obsessing, hoarding and neutralizing category. The OCI-R has been found to
have excellent psychometric properties (Foa, et al., 2002; Hajcak, Huppert, Simons, & Foa, 2004).
In particular, OCI-R has shown very good to excellent internal consistency, test-retest reliability
and convergent validity both in clinical populations and in normal controls.
Other self-report measures for OCD also have been devised, but deemed insufficient for a
variety of reasons. For instance, Maudsley Obsessive-Compulsive Inventory (MOCI) (Hodgson &
Rachman, 1977) has received major criticism because it has poor internal consistency and also fails
to fully capture all the symptoms of OCD (Thordarson, Radomsky, Rachman, Shafran, Sawchuk, &
Hakstianet, 2004). Other self-report measures, such as the Padua Inventory of Obsessive-
Compulsive Symptoms (Sanavio, 1988) or the Vancouver Obsessional Compulsive Inventory
(Thordarson, et al., 2004), also have been criticized due to their large size and the prolonged time
required for their completion. Fairly recently, Abramowitz et al. (2010) developed the Dimensional
Obsessive-Compulsive Scale (DOCS) to capture and assess the heterogeneous nature of the OCD
symptomatology. Although DOCS has been found to be a sound measure of OCD, it also can be
time consuming to administer. Further, its properties have not yet fully been re-examined across
diverse cultural settings.
On the contrary, several studies have translated and validated OCI-R in different cultural
settings, including Spain, Germany, France, Korea, China, Turkey and Iceland, verifying that the
scale has very good or excellent psychometric properties (Aydin, Boysan, Kalafat, Selvi, Besiroglu,
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& Kagan, 2014; Fullana, Tortella-Feliu, Caseras, Andion, Torrubia, & Mataix-Cols, 2005; Gonner,
Leonhart, & Ecker, 2008; Smári, Ólason, Eypórsdóttir, & Frölunde, 2007; Tang, Yu, He, Wang,
Chasson, 2015; Zermatten, van der Linden, Jermann, & Ceschi, 2006; Woo, Kwon, Lim, & Shin,
2010). Of note, nearly half of the translated versions of OCI-R have been validated among non-
clinical populations (Fullana et al., 2005; Smari et al., 2007; Zermatten et al., 2006). Validating
OCI-R in community samples is important because the frequency of OCD-related behaviors is
considerably high in the general population. For instance, Fullana et al. (2010) found a lifetime
prevalence of 13% in any of the symptom categories that characterize OCD in the general
population. Research evidence also suggests that non-clinical participants, who self-report high
scores in obsessive-compulsive inventories, tend to produce stable obsessive-compulsive behaviors
across time, which closely correspond to those observed in clinical patients diagnosed with OCD
(Burns, Formea, Keortge, & Sternberger, 1995). Moreover, the use of a community sample
facilitates the investigation of the factor structure and the evaluation of the psychometric properties
of OCI-R (e.g., Sica et al., 2009).
Among the limitations of OCI-R’s scale is that its discriminant validity is only adequate to
good, likely because OCD usually co-exists with other disorders, with major depression possessing
a significant place among Axis I comorbid conditions commonly diagnosed with OCD (e.g.,
Abramowitz & Deacon, 2006; Foa et al., 2002; Tükel, Polat, Özdemir, Aksüt, & Türksoy, 2002).
Further, order effects have been observed when it is administered after another measure of OCD
(Hajcak et al., 2004; Woo et al., 2010). Gender effects also have been found in some cultural
settings. For instance, Spanish men have been found to have more hoarding and checking
complaints than Spanish women (Fullana et al., 2005), whereas Italian men score higher on
washing, checking and obsessing sub-scales than women of the same culture (Sica et al., 2009). In
Iceland, these findings are reversed with women reporting more complaints on the checking and
ordering sub-scales compared to men (Smári et al., 2007).
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A Greek version of the OCI-R does not exist. This is an important gap in the literature that
needs to be addressed for both research and clinical reasons. In terms of research, a Greek version
of the OCI-R would facilitate the research process and the direct comparison of studies focusing on
OCD in the Greek settings with studies conducted in other European or US settings. Clinically,
there is evidence that the frequency of OCD-related behaviors is considerably higher in Greek
samples compared to samples from other cultures. For instance, the mean score of the Hellenic
version of Spence Children’s Anxiety Scale (SCAS-GR; Mellon & Moutavelis, 2007) measuring
compulsive behavior in children aged from 9 to 12 years old was 82% higher compared to the mean
of the original scale (Spence, 1997), which was comprised of Australian children of the same age.
To date, there is no evidence with regard to the frequency of occurrence of OCD symptoms
in a Greek adult community sample, most probably due to the absence of a validated self-report
measure of OCD in Greece. Given the necessity of the existence of such an instrument, which
would reliably assess the frequency of OCD symptoms, an effort has been undertaken to translate
and validate OCI-R in the Greek context. The overarching aim of the present study was (a) to
evaluate the factor structure and the psychometric properties of the Greek-version of OCI-R in a
large community sample, (b) to overcome its previous limitations (e.g., discriminant validity) by
applying traditional and alternative validating methods, and (c) to test different structural models
according to the new research findings. Last, in view of the inconsistent findings that have been
produced with regard to the existence of both gender and order effects in other cultural settings
(Fullana et al., 2005; Hajcak et al., 2004; Sica et al., 2009, Smári et al., 2007; Woo et al., 2010), the
potential influence of gender differences and order effects on the administration of the Greek
version of OCI-R also was examined.
Method
Participants
In total, 1379 participants from the general community (31% males and 69% females) aged
from 18 to 83 years old (M = 27.54, SD = 10.76) completed the OCI-R scale. Potential participants
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had to satisfy the following criteria to be included in the study: (a) speak Greek fluently, and (b) be
Greek residents/citizens. Participation was voluntarily for all participants and informed consent was
obtained prior to scale completion. Approximately less than half of the participants (44%) were
university students, whereas 33.2% of the remaining participants had received university education
(e.g., first degree or master’s level). Only 5.6% of the study sample was unemployed and only 2%
had retired. With regard to the socio-economic status (SES), 24.8% of the study sample declared an
average household income of 600 euros per month (low SES), 46.6% declared a monthly income
ranging from 1200 to 2100 (middle SES), whereas the rest 28.6% of the sample declared making
more than 2100 euros per month (high SES). Fewer participants completed the total study measures
as detailed in Tables 6 and 7. No payments or course credits were offered for their participation.
Measures
Obsessive-compulsive inventory-revised (OCI-R) (Foa et al., 2002)
OCI-R consists of 18 items that measure distress caused by OCD symptoms. Participants’
scores are rated in a 5-point scale ranging from 0 = never to 4 = very much. OCI-R also consists of
six sub-scales, including washing, checking, orderliness, hoarding, neutralization and obsessions. In
the current study a Greek version of the OCI-R was used. The scale was translated from English to
Greek and back to English by six independent raters (three raters translated the scale from Greek to
English and the other three translated it from English to Greek). The accuracy of these translations
was reviewed by the authors of the study (IA, MP). In this study, the alpha coefficient was 0.89 for
the overall scale (see, Table 2). The final version of the Greek version of the scale is presented in
Appendix.
Maudsley obsessive-compulsive inventory (MOCI) (Hodgson & Rachman, 1977)
MOCI consists of 30 true-false statements that assess the frequency of OCD symptoms. It
covers four areas of complaints, that is, checking, cleanliness, slowness and doubting. MOCI has
good internal consistency and good to very good test-retest reliability and convergent validity
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(Emmelkamp, Kraaijkamp, & Van den Hout, 1999; Stoylen, Larsen, & Kvale, 2000). The alpha
coefficient for this scale was found to be very good, Cronbach’s α = 0.81, whereas the 30-day test-
retest reliability was excellent (0.83) in this study, suggesting proper psychometric qualities
(McCrae, Kurtz, Yamagata, & Terracciano, 2011).
Launay-Slade hallucinations scale (LSHS) (Launay & Slade, 1981)
LSHS is a 16-item self-report questionnaire that measures healthy individuals’
predisposition towards hallucinations. Responses are recorded in a 4-point scale, which range from
1 = never to 4 = very frequently. It incorporates three types of hallucinations, namely, intrusive
mental events, auditory religious and visual religious hallucinations. In this dataset, LSHS was
found to have excellent internal consistency, Cronbach’s a = 0.88, and an excellent 30-day test-
retest reliability (0.82), suggesting appropriate psychometric properties (McCrae, Kurtz, Yamagata,
& Terracciano, 2011).
Centre for epidemiological studies depression scale (CES-D) (Radloff, 1977)
CES-D consists of 20 items that measure the severity of depressive symptoms in the general
population. Participants self-report their answers in a 4-point scale by marking the number that
better describe their mood or feelings during the past week. CES-D scores range from 0 = rarely to
3 = most of the times. It has been found to have very good to excellent psychometric properties
(Fountoulakis et al., 2001). In the current study, the alpha coefficient was high, Cronbach’s a =
0.86, and the 1-month test-retest reliability was excellent (0.83).
Procedure
The first author, who had a first degree in Psychology and a postgraduate professional
qualification in Psychology, together with undergraduate Psychology students from Panteion
University, approached prospective participants. The majority of the student population was
comprised of participants mainly from Panteion University or National & Kapodistian University of
Athens. The non-student population was recruited from local coffee shops, cinemas and other
merchants. The first author and research assistants visited these establishments and recruited
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participants by asking customers if they would like to complete the survey. Those that agreed were
given a written consent form that informed them of the voluntary nature of the study. If they signed
the form, they were then taken to a quiet area of the establishment to complete the survey. After the
completion of the survey, participants were verbally debriefed regarding the aims of the study using
a script, so that debriefing statements were consistent across researchers. Data on a number of key
demographic characteristics (i.e., age, gender, occupation, socio-economic status) also were
recorded. Completion of these measures lasted approximately 20 min. To examine test-retest
reliability, the OCI-R was distributed again to 108 participants (56.5% of the sample was comprised
of undergraduate students) 30 days after its initial administration.
Data analyses
All statistical analyses were conducted using the IBM SPSS® (version 23.0) or the AMOS®
(version 23.0) statistical software. Study’s variables were tested for normality by assessing the
measure of skewness for every item, which revealed no deviation from a normal distribution. In the
current analysis both an explanatory factor analysis (EFA) and a confirmatory factor analysis (CFA)
were utilized. This decision was based on three reasons: (a) the symptoms that describe a number of
mental health disorders are possible to differ at least slightly among different cultural contexts, (b)
this is the first attempt to adapt the OCI-R in a Greek setting and therefore it is critical to explore
the structure of the Greek-version of the OCI-R (e.g., Gerbing & Hamilton, 1996), and (c) the mean
scores of the overall scale and the sub-scales of OCI-R were found to be exceptionally high, nearly
approaching the mean scores of the original study for the patient population sample. EFA also is
more appropriate for appraising the factor structure of an instrument, which has been in an initial
stage of development or validation within a particular cultural setting, and reducing multiple
observed variables into fewer components that summarize their variance (see, Byrne, 2001). To this
end, an EFA with promax rotation was employed, because the factors of the scale correlated
significantly with one another, together with a CFA. For the CFA, the maximum likelihood
estimation method was used. We tested the fit of the overall scale, a five-factor model by omitting
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the hoarding sub-scale in accordance with the new recommendations and a six-factor model that
have been proposed by the vast majority of the studies validating OCI-R in either clinical or
community samples across different social settings. Test-retest reliability was assessed by
producing Pearson product-moment correlation coefficients from Time 1 (initial administration) to
Time 2 (30 days later) administrations of the scale. Pearson’s r coefficients also were produced to
examine the inter-factor correlations of the OCI-R and to assess the convergent and discriminant
validity of the scale. In addition, we explored convergent validity by computing Average Variance
Extracted (AVE) scores, discriminant validity by producing square roots for AVE, and the internal
consistency by calculating Composite Reliability (CR) scores for each of the suggested factors of
the model. Independent-samples t-tests were conducted to explore potential gender differences on
the scores of OCI-R for the total, non-college and the college study’s samples and to examine the
possibility of an order effect.
Missing values
Initial screening revealed 76 cases with missing values in the OCI-R and in additional study
measures. A non-significant Little’s MCAR test, x2(220) = 208.09, p = 0.71, suggested data missing
completely at random (Little, 1988). To this end, single imputation methods using maximization
expectation algorithm were performed (Scheffer, 2002). The imputed scores were used for both the
EFA and CFA analyses. Then, we repeated all factor analyses to ensure that our findings remained
unchanged and unbiased. With regard to subsequent analyses (e.g., correlations) and in line with
recommendations (e.g., Rubin, 1987), we performed multiple imputations analyses. These scores
entered the final analyses. Again, in order to ensure that our interpretation was not biased, we
performed all the analyses with and without the imputed values.
Results
Descriptive statistics
The means and standard deviations of the OCI-R across the male and female participants of
the total, non-college and college study samples are detailed in Table 1. In general, the overall mean
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of the OCI-R of the current study (M = 26.82, SD = 12.79) closely resembled the overall mean
reported for the patient population (M = 28.01, SD = 13.52), but not for the non-anxious controls
(M = 18.82, SD = 11.10) of the original study (Foa et al., 2002). A number of additional differences
also were found. For example, higher means in the ordering (M = 5.96, SD = 3.24) and hoarding
sub-scales (M = 4.75, SD = 2.96), but lower means in the obsessing (M = 5.13, SD = 3.24),
neutralizing (M = 2.51, SD = 2.63) and washing sub-scales (M = 3.72, SD = 3.11) were reported in
this sample compared to the patient one of the original OCI-R version. The mean of the checking
sub-scale (M = 4.73, SD = 3.32) was found to be similar to the one reported by Foa et al. (2002).
On average, females of the total study sample self-reported more obsessions (M = 5.32, SE =
0.14) than males (M = 4.76, SE = 0.21), t(1377) = -3.37, p < 0.001, d = 0.20. Overall, females of the
non-college sample reported more obsessive-compulsive symptoms (M = 28.55, SE = 0.57) than
males (M = 26.10, SE = 0.82), t(770) = -2.41, p < 0.05, d = .19, more washing (M = 4.15, SE =
0.14) than males (M = 3.66, SE = 0.20), t(770) = -1.98, p < 0.05, d = 0.16, more obsessions (M =
5.32, SE = 0.14) than males (M = 4.76, SE = 0.21), t(770) = -2.22, p < 0.05, d = 0.17, and more
ordering concerns (M = 6.50, SE = 0.14) than males (M = 5.32, SE = 0.22), t(707) = -2.81, p < 0.05,
d = 0.20. With regard to the college study sample, we found that on average men self-reported more
neutralizing (M = 2.82, SE = 0.22) than women (M = 2.18, SE = 0.12), t(605) = 2.81, p < 0.05, d =
0. 23. Females reported, on average, more obsessions (M = 5.33, SE = 0.16) than men (M = 4.61,
SE = 0.22), t(605) = -2.57, p < 0.05, d = 0. 22. Although statistically significant, the aforementioned
differences between males and females are translated into minimal or small effect sizes.
[Table 1 about here]
Factor structure of the scale
An EFA was conducted on the 18 items with the promax rotation method due to the strong
inter-factor correlations. The Kaiser-Meyer-Olkin measurement confirmed that the sample size was
adequate to perform such an analysis, KMO = 0.87 and the KMO values for all items separately
were > 0.66, above the recommended value of 0.6. Bartlett’s test of sphericity x2 (153) = 10212.420,
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p < 0.001, indicated that the correlations between the items were sufficiently large to perform this
analysis. Initially, a first analysis produced six independent factors based on the eigenvalues, which
exceeded the Kaiser criterion (which is 1) and in combination explained 70.29% of the total
variance. The scree plot also supported the six-factor solution for this scale based on the
eigenvalues. Table 2 presents the factor loadings of the OCI-R scale after performing a promax
rotation, together with the eigenvalues, the percentage of variance accounted for and the Cronbach’s
alphas for each of the extracted factors. The items concentrated around the same components
suggest that factor 1 represents checking, factor 2 ordering, factor 3 obsessing, factor 4 hoarding,
factor 5 washing and factor 6 neutralizing.
[Table 2 about here]
Construct validity
A CFA was conducted to evaluate the fit of the data to the six-factor structure solution that
was initially suggested by the original OCI-R scale development and also confirmed in this study by
performing an EFA. The model had a significant Chi-square, x2(120) = 555.71, x2/d.f. = 4.63, p <
0.001, which is explained by the utilization of a large dataset and therefore must be ignored
(Jöreskog & Sörbom, 1993). As detailed in Table 3, the goodness-of-fit indices indicated that the
six-structure model of the Greek version of OCI-R was supported. In particular, the model had a
Goodness-of-Fit Index (GFI) of 0.96, a Comparative Fit Index (CFI) of 0.96, a root-mean-square
residual (RMR) of 0.06, and a root-mean-square error of approximation (RMSEA) of 0.05 (for
cutoff criteria for fit indexes see, Hu & Bentler, 1999). We also examined a five-factor model by
excluding the hoarding sub-scale. This model had a significant Chi-square, x2(80) = 355.85, x2/d.f. =
4.44, p < 0.001, a Goodness-of-Fit Index (GFI) of 0.97, a Comparative Fit Index (CFI) of 0.97, a
root-mean-square residual (RMR) of 0.05, and a root-mean-square error of approximation
(RMSEA) of 0.05, indicating a slightly better conceptual fit of the data. A one-factor model also
was tested but data clearly failed to fit this model.
[Table 3 about here]
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Congruence coefficients
Tucker’s congruence coefficients were calculated as an index of similarity between the
original and the Greek version of OCI-R factor loadings as were detected in Foa’s et al. (2002) and
the current study’s datasets. As shown in Table 4, a high degree of factor similarity was observed
among all the six factors as were proposed by the original study and replicated in the Greek context,
with rc ranging from 0.82 to 0.89.
[Table 4 about here]
Internal consistency of the overall scale and its sub-scales
Cronbach’s coefficients were calculated for all the six constructs as shown in Table 2. All
but the neutralizing construct showed an internal consistency higher than the recommended value
(alpha < 0.70). The alpha coefficient was 0.89 for the overall OCI-R. We also examined composite
reliability (CR) by calculating CR indexes for each of the constructs. CRs were exceeded the
recommended value of 0.06 for all the six sub-scales.
Test-retest reliability
Pearson’s correlation coefficients were calculated to assess test-retest reliability for OCI-R
as shown in Table 5. Overall, the test-retest reliability for the total scale and the sub-scales was very
good to excellent, ranging from 0.70 to 0.81. The test-retest for the total OCI-R was found to be
excellent (r = 0.81) in a one-month period. The hoarding (r = 0.70), neutralizing (r = 0.71) and
obsessing (r = 0.74) sub-scales showed the lowest test-retest reliabilities, whereas the ordering (r =
0.77), the washing (r = 0.79) and the checking (r = 0.81) sub-scales showed an excellent one-month
test-retest reliability.
[Table 5 about here]
Inter-correlations between OCI-R and its sub-scales
As detailed in Table 6, the overall OCI-R was strongly correlated with all the sub-scales (r
ranges from 0.59 to 0.75) indicating that the six factors together with the overall scale represent the
same theoretical concept (e.g., symptoms of OCD). The inter-correlations among the sub-scales
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ranged from 0.22 to 0.52 suggesting a sufficient but not satisfactory relationship among the
different sub-scales of the OCI-R, which supports further the existence of multidimensionality in
OCD.
[Table 6 about here]
Convergent validity
As shown in Table 7, the correlation of the overall OCI-R with the overall MOCI was high
(r = 0.67), indicating a very good convergent validity. MOCI also correlated highly with the
washing (r = 0.56) and the checking (r = 0.55) sub-scales of OCI-R. The obsessing (r = 0.49),
ordering (r = 0.45) and neutralizing (r = 0.42) scales also were satisfactorily correlated with MOCI,
whereas the hoarding scale (r = 0.31) showed the lowest correlation with the overall MOCI. The
checking sub-scale of OCI-R correlated highly with the checking sub-scale of MOCI, (r = 0.57) and
the washing sub-scale of OCI-R also correlated highly with the cleaning sub-scale of MOCI, (r =
0.53). Further, the calculations of the AVE indexes verified that convergent validity was achieved
because all indexes were 0.5 or higher.
[Table 7 about here]
Discriminant validity
The Pearson’s correlation coefficients between the total OCI-R and its sub-scales with the
CES-D and LSHS are presented at Table 8. The results indicated moderate correlations between the
OCI-R with both the CES-D and LSHS (r = 0.47 and r = 0.47 respectively). The obsessing scale
correlated moderately with CES-D (r = 0.39), whereas the rest sub-scales of OCI-R were correlated
only moderately to weakly with the CES-D, ranging from r = 0.31 to r = 0.33. The obsessing scale
was correlated moderately with the LSHS (r = 0.42), whereas moderate or weak correlations were
found between the LSHS and the other sub-scales of the OCI-R, ranging from r = 0.24 to r = 0.39.
Table 6 also presents the square roots of AVE indexes for all the six constructs. These results
indicate that discriminant validity was achieved because all indexes (diagonal values in bold) were
found to be higher than the values in their rows and columns. Further, none of these indexes
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exceeded the critical value of 0.85, which suggests the existence of a redundant factor or serious
multicollinearity problems.
[Table 8 about here]
Order effects
On average, participants tended to score higher on OCI-R when it was administered after
MOCI (M = 27.74, SE = 0.53) than when it was administered first (M = 26.04, SE = 0.50), t(1377) =
2.33, p > 0.05, d = 0.13. However, these differences represented only minimal effect sizes.
Discussion
The current study evaluated the psychometric properties of a Greek version of OCI-R in a
large community sample. The results clearly demonstrated that the Greek version of OCI-R has
excellent psychometric properties. A core strength of this study is that we utilized a large non-
clinical population comprised of both university students and individuals from the community.
In accordance with the original version of the OCI-R and other translated versions, the
factor structure of the scale yielded six independent factors, namely, checking, ordering, obsessing,
hoarding, washing and neutralizing, conforming to the six factor solution of the original scale
(Aydin et al., 2014; Gonner et al., 2008; Foa et al., 2002; Fullana et al., 2005; Smári et al., 2007;
Zermatten et al., 2006; Woo et al., 2010). A CFA also suggested an excellent fit for the six-factor
solution, whereas Tucker’s correlation coefficients also confirmed the existence of a high degree of
factor similarity between the original and Greek factors of the OCI-R scale. Given the current
changes in the DSM-5, where hoarding symptoms compose a whole new disorder, we also tested a
five model fit by omitting the hoarding sub-scale. This model was found to be slightly superior to
the original six-model structure of the OCI-R. Therefore, in line with recent evidence (Wootton
Diefenbach, Bragdon, Steketee, Frost, & Tolin, 2015), we recommend that the five-scale of OCI-R
can be used reliably. Finally, we tested the model fit for the overall scale, but clearly CFA failed to
support a one-factor solution for the OCI-R scale, supporting, thus, the heterogeneity of the
symptoms characterizing OCD.
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With regard to the internal consistency, it was found to be excellent for the overall scale and
very good to excellent for five of the sub-scales. Only the neutralizing sub-scale showed an internal
consistency lower than the recommended value (alpha < .70; see, Nunnally, & Bernstein, 1994).
However, this result is consistent with the findings of the vast majority of the studies that adapted
OCI-R in different cultural settings or populations (Aydin et al., 2014; Hajack et al., 2005; Fullana
et al., 2005; Smári et al, 2007; Zermatten et al., 2006; Woo et al., 2010). The low internal
consistency of the neutralizing sub-scale likely results from the fact that two of the sub-scales’
items focus primarily on counting behaviors, whilst another item focuses on assessing superstitious
cognitions. We tested this possibility by computing composite validity indexes, which have been
suggested to be superior to alpha coefficient when testing sub-scales (Raykov, 1998). CRs
confirmed the existence of a high internal consistency for all the sub-scales, suggesting that the sub-
scales’ items hold strong together in measuring the same constructs.
All, but the hoarding sub-scale, correlated strongly with the overall OCI-R. This finding
suggests that all the sub-scales, but the hoarding, can reliably differentiate participants who self-
report symptoms of OCD from participants who do not report such symptoms (e.g., Mataix-Cols et
al., 2005). A low correlation between the hoarding sub-scale and the overall OCI-R has been
reported repeatedly in the literature (e.g., Foa et al., 2002; Woo et al., 2002), suggesting that
hoarding may not be a fully representative feature of this disorder (Grisham & Norberg, 2010;
Mataix-Cols et al, 2010; Steketee & Frost, 2003). Indeed, in DSM-5, hoarding is not anymore listed
as a criterion for the diagnosis of OCD, but rather comprises a distinct disorder, which is classified
under the obsessive-compulsive and related disorders chapter (APA, 2013). Further, data of a recent
study suggested that the OCI-R’s three-item hoarding sub-scale can reliably differentiate between
hoarders and non-hoarders (Wootton et al., 2015).
The convergent validity between the OCI-R with the MOCI was strong, confirming that
OCI-R has been developed to measure symptoms that indicate OCD. Similar findings have been
reported by Hajcak et al. (2004) and Smári et al. (2007), who also found strong associations
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between the total OCI-R and MOCI (r = 0.67 and r = 0.60 respectively). Although Foa et al. (2002)
reported a much higher correlation between OCI-R and MOCI (r = 0.85), variations in sample used
across studies might account for this difference. Indeed, Foa et al. (2002) utilized a clinical sample,
while this study was based on a community sample. Consistent with this explanation, two other
studies, which used community samples, reported similar correlations between OCI-R and MOCI to
the ones reported in the current study (see, Hajcak et al., 2004; Smári et al., 2007). We also
produced AVE scores, which fully supported that the Greek version of OCI-R achieved convergent
validity. We highly recommend that future studies calculate such scores, especially in cases where
there is ambiguity with regard to the validity of a measure.
Consistent with the evidence suggesting that OCD has common features with depression and
hallucinations (e.g., Guillem, Satterthwaite, Pampoulova, & Stip, 2009; Nestadt et al., 2001; Shioiri,
Shinada, Kuwabara, & Someya, 2007), we anticipated that a moderate association between OCI-R
and CES-D or LSHS would be a good estimate of OCI-R’s discriminant validity. Indeed, OCI-R
was moderately associated with both the CES-D and LSHS scales indicating adequate discriminant
validity. In accordance with our results, the vast majority of the studies that have validated OCI-R
in other cultural settings or re-examined OCI-R’s psychometric properties have reported the
existence of a good or adequate discriminant validity (Hajcak et al., 2004; Fullana et al., 2005; Sica
et al., 2009; Smári et al., 2007; Woo et al., 2010), including the original development study (Foa et
al., 2002), likely due to the high comorbidity between the diagnosis of OCD and other Axis I
disorders, especially major depression (Abramowitz & Deacon, 2006; Tükel et al., 2002). We tested
this possibility by producing squares roots of AVE scores. Clearly, our analyses supported the
discriminant validity for this scale.
Of note, the total OCI-R yielded a mean score almost as high as the one reported by Foa et
al. (2002) despite the fact that the original study was based on a clinical population. Consistent with
this finding, the Greek version of the OCI-R showed the highest one-month test-retest reliability
that has been reported in the literature that closely resembled the findings of the original scale in the
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patient population (Foa et al., 2002). This finding suggests that the exceptionally high mean scores
of OCD symptoms found in the Greek community sample remain stable over time. It is interesting
to note that Fountoukakis et al. (2001), who validated a Greek version of the CES-D, reported no
mean differences between depressed patients and healthy controls, suggesting that the symptoms
that characterize depression were significantly elevated in Greek populations. Further, Mellon
(2000) found that self-reported fears were considerably higher in Greek children and adults
compared to other cultures. Coercive parenting and educational practices, together with adverse
social interactions, have been reported to play a role in the development of both OCD and
depressive features in American study samples (e.g., Afifi, Mota, Dasiewicz, MacMillan, & Sareen,
2012), so it is possible that these may be the critical factors in explaining the prevalence of OCD
and depression in Greece. Previous studies conducted in Greece (e.g., Mellon, 2000; Mellon &
Moutavelis, 2007) reported that among the crucial factors that differentiate the Greek culture from
other Mediterranean or European cultures are child-rearing practices that bring specific attention to
the dangers that exist outside the safety of one’s home. Further, the Greek educational system has
been characterized as harsh and punitive, which may contribute to the development of compulsive
and related behaviors to avoid and/or escape the anxiety generated by such pedagogic practices.
However, further research will be needed to replicate the outcomes of the current study and to
examine the underlying mechanisms that account for the high prevalence of OCD and other Axis I
disorders in the Greek community. We believe our findings will serve as an important basis for that
research.
No considerable gender differences were found in the total OCI-R. However, women of
both the total and the non-college samples tended to report more frequent obsessions than men, a
finding which was translated into small effect sizes. Further, women of the non-college sample
reported more concerns with washing and ordering compared to men, but the effect sizes of these
differences were only small. Conversely, men of the college sample tended to report neutralizing
more often compared to women, but this difference was translated into a small effect size. Overall
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and consistent with the extant literature, no considerable differences have been reported between
men and women with regard to self-reporting OCD symptoms across different cultures.
OCI-R produced slightly higher overall scores, when followed MOCI. Although, Foa et al.
(2002) and Woo et al. (2008) reported a slight decrease on the scores of the overall OCI-R when it
followed another obsessive-compulsive scale, we found the opposite pattern of results. One
plausible explanation is that a repetitious examination of the OCD symptoms might increase
participants’ awareness with regard to the purposes of the study. However, following calculation of
the effect sizes we found that clinical significances of these results are only minimal.
Strengths & limitations
This study has several strengths. Given the necessity for the existence of a validated scale,
our analysis confirmed that the Greek version of OCI-R is a sound psychometric tool for assessing
symptoms of OCD in the Greek context. This study utilized both classical (e.g., based on EFA and
Cronbach’s alpha) and modern (e.g., based on structural equation modelling) methods for
evaluating the psychometric properties of the Greek OCI-R. By doing this, we overcame previous
limitations that suggested OCI-R to have only adequate discriminant validity, or poor internal
consistency for the neutralizing sub-scale. Further, to the best of our knowledge, this is the first
study that demonstrated that a five-factor model provided a slightly better conceptually fit of the
data conforming thus to the latest findings and revisions of the DSM-V. Last, we demonstrated that
the use of contemporary validating methods, even if they are more conservative, can overcome
limitations inherited in the classical methods (e.g., Bagozzi, Yi, & Phillips, 1991). Therefore, we
encourage future researchers to apply these techniques alone or in combination with more
traditional ones.
Despite its strengths, some limitations should be noted. First, despite the utilization of a
large study sample, no participants with a clinical diagnosis of OCD were included in this study.
Although OCI-R was developed for use in both clinical and non-clinical populations, it would be
interesting to re-examine the psychometric properties of OCI-R in patients who have received a
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clinical diagnosis of OCD. Second, although the mean scores of the OCI-R was found to be much
higher in a Greek sample compared to those reported in other countries, a finding that is consistent
with the mean scores found in the Greek versions of similar scales measuring symptoms of
depression, anxiety, and fears, the reasons of this variation are unknown and remain to be explored
by future studies. Third, more than two-thirds of the participants were females, which might have
obscured the effect sizes of the differences detected between the males and females. Lastly, the vast
majority of the participants had received university education; therefore, the results might not
necessarily be representative of people with no or little education.
Compliance with Ethical Standards
Role of funding sources: No financial support has been received.
Conflict of interest: All authors declare no conflict of interest.
Ethical approval: All procedures performed in this study were in accordance with the ethical
standards of the institutional and/or national research committee and with the 1964 Helsinki
declaration and its later amendments or comparable ethical standards.
Informed consent: Informed consent was obtained from all individual participants included in the
study.
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Table 1Means and standard deviations of the overall OCI-R and its sub-scales for the total and college sample
Checking Ordering Obsessing Hoarding Washing Neutralizing OCI-R
M SD M SD M SD M SD M SD M SD M SD N % t✝ P value
Total sample
Men 4.62 3.39 5.72 3.21 4.69** 3.11 4.52 2.90 3.54 3.02 2.80 2.72 25.72 12.53 428 31.04
Women 4.78 3.29 6.07 3.25 5.32** 3.27 4.85 2.98 3.88 3.14 2.38 2.58 27.31 12.88 951 68.46
Total 4.73 3.32 5.96 3.24 5.13 3.24 4.75 2.96 3.72 3.11 2.51 2.63 26.82 12.79 1379 100 -2.15 0.03
Non-college sample
Men 4.77 3.44 5.85* 3.39 4.76* 3.14 4.54 3.01 3.66 3.12* 2.78 2.47 26.10 12.54 232 16.82
Women 5.09 3.35 6.50* 3.21 5.32* 3.27 4.87 3.09 4.14 3.19* 2.53 2.65 28.55 13.13 540 39.16
Total 4.99 3.37 6.30 3.26 5.16 3.24 4.78 3.07 4.00 3.17 2.61 2.60 27.81 13.00 772 55.98 -2.41 0.02
College sample
Men 4.44 3.34 5.56 2.99 4.61* 3.09 4.50 2.78 3.40 2.91 2.67* 2.76 25.26 12.53 196 14.21
Women 4.37 3.16 5.50 3.22 5.33* 3.29 4.82 2.82 3.52 3.06 2.82* 3.00 25.68 12.38 411 29.81
Total 4.39 3.22 5.52 3.15 5.09 3.24 4.72 2.81 3.48 3.01 2.18 2.47 25.55 12.42 607 44.02 -.39 0.70
Note. OCI-R = Obsessive Compulsive Inventory - Revised.* Statistical significant differences between males and females, p < 0.01** Statistical significant differences between males and females, p < 0.001 ✝ t-scores were calculated on the overall OCI-R between males and females for the total, non-college and college sample.
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Table 2Summary of exploratory factor analysis results from the OCI-R (N = 1379)
Rotated Factor Loadings
Items Checking Ordering Obsessing Hoarding Washing Neutralizing
14 0.91 -0.04 0.06 -0.05 0.02 -0.01
8 0.88 -0.01 -0.01 0.02 0.08 -0.05
2 0.82 0.05 -0.04 0.06 -0.08 0.06
15 -0.05 0.86 -0.04 -0.05 0.03 0.06
3 0.11 0.85 0.00 -0.06 -0.08 -0.01
9 -0.12 0.81 0.05 0.10 0.08 -0.07
18 0.03 -0.01 0.88 0.00 -0.01 0.06
12 -0.01 0.11 0.83 -0.01 0.00 0.02
6 0.00 -0.07 0.81 0.03 -0.04 -0.06
7 -0.03 -0.06 0.01 0.89 0.01 -0.01
1 0.03 -0.05 -0.05 0.77 -0.07 0.06
13 0.03 0.01 0.08 0.77 0.08 -0.05
11 -0.08 -0.01 0.07 0.01 0.87 -0.01
5 0.02 0.01 -0.16 0.03 0.86 0.02
17 0.13 0.04 0.07 -0.05 0.71 0.03
10 0.00 -0.07 0.03 0.00 0.01 0.85
16 -0.06 -0.07 0.05 -0.05 0.10 0.78
4 0.05 0.16 -0.09 0.08 -0.08 0.69
Eigenvalues 6.17 1.85 1.30 1.18 1.14 1.03
% of variance 34.27 10.28 7.21 6.57 6.33 5.60
a 0.84 0.79 0.80 0.76 0.78 0.67
Note: Factor loadings over 0.60 appear in bold.
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Table 3 Goodness-of-Fit Indicators of the Greek version of OCI-R (N = 1379)
Model X2* df x2/df GFI CFI RMR RMSEA
One-Factor 4010.78 135 29.71 0.74 0.62 0.15 0.14
Five-Factor 355.85 80 4.44 0.97 0.97 0.05 0.05
Six-Factor 555.71 120 4.63 0.96 0.96 0.06 0.05
Note. *p <0.001.
Table 4 Tucker’s coefficient of congruence between factor loadings for the OCI-R from the Greek and Foa’s et al. (2002) dataset
1 2 3 4 5 6
Checking 0.88
Ordering 0.87
Obsessing 0.87
Hoarding 0.85
Washing 0.86
Neutralizing 0.82
Note. OCI-R = Obsessive Compulsive Inventory - Revised.
Table 5Test-retest reliability for overall OCI-R and its sub-scales (Ν = 108)
Pearson’sCorrelation
Coefficient (r)
Checking 0.81
Ordering 0.77
Obsessing 0.74
Hoarding 0.70
Washing 0.79
Neutralizing 0.71
OCI-R 0.81
Note: All correlations are significant in level p < 0.001, OCI-R = Obsessive Compulsive Inventory-Revised, Ν = Total number of participants.
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Table 6Square root of AVE and pearson inter-correlations between the overall OCI-R scale and its sub-scales (Ν = 1379)
1 2 3 4 5 6 OCI-R
Checking 0.81 0.75
Ordering 0.48 0.77 0.71
Obsessing 0.38 0.34 0.78 0.70
Hoarding 0.34 0.22 0.40 0.72 0.59
Washing 0.52 0.47 0.42 0.27 0.74 0.73
Neutralizing 0.42 0.39 0.35 0.29 0.42 0.69 0.67
Note: All correlations are significant in level p < 0.001, OCI-R = Obsessive Compulsive Inventory-Revised, Ν = Total number of participants.
Table 7Convergent validity of the OCI-R and its sub-scales with MOCI and its sub-scales, AVE and CR indexes* (Ν = 1052)
Checking Cleaning MOCI AVE* CR*
Checking 0.57 0.34 0.55 0.66 0.93
Ordering 0.38 0.35 0.45 0.58 0.91
Obsessing 0.52 0.27 0.49 0.60 0.92
Hoarding 0.33 0.17 0.31 0.52 0.89
Washing 0.46 0.53 0.56 0.54 0.89
Neutralizing 0.41 0.21 0.42 0.51 0.87
OCI-R 0.65 0.44 0.67 - -
Note: All correlations are significant in level p < 0.001, OCI-R = Obsessive Compulsive Inventory-Revised, MOCI = Maudsley Obsessive Compulsive Inventory.* AVE & CR indexes were calculated utilizing the entire study sample, N = 1379
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Table 8Discriminant validity of the OCI-R with CES-D and LSHS (Ν = 1052)
CES-D LSHS
Checking 0.33 0.28
Ordering 0.33 0.24
Obsessing 0.39 0.42
Hoarding 0.31 0.31
Washing 0.32 0.35
Neutralizing 0.31 0.39
OCI-R 0.47 0.47
Note: All correlations are significant in level p < 0.001, OCI-R = Obsessive Compulsive Inventory-Revised, CES-D = Centre for Epidemiological Studies Depression Scale, LSHS = Launay-Slade Hallucinations Scale.
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Appendix A
The Greek version of the OCI-R
The following statements refer to experiences that many people have in their everyday lives. Circle the number that best describes HOW MUCH that experience has DISTRESSED or BOTHERED you during the PAST MONTH. The numbers refer to the following verbal labels
Οι παρακάτω προτάσεις αναφέρονται σε εμπειρίες που πολλοί άνθρωποι έχουν στην καθημερινή ζωή. Κυκλώστε τον αριθμό που περιγράφει καλύτερα το ΠΟΣΟ ΠΟΛΥ αυτή η εμπειρία σας έχει ΣΤΕΝΑΧΩΡΗΣΕΙ ή ΕΝΟΧΛΗΣΕΙ κατά τη διάρκεια του προηγούμενου μήνα. Οι αριθμοί αναφέρονται στις παρακάτω λεκτικές σημασίες: 0 1 2 3 4
Not at allΚαθόλου
A littleΛίγο
ModerartelyΜέτρια
A lotΠολύ
ExtremelyΠάρα πολύ
1. I have saved up so many things that they get in the way. Έχω φυλάξει τόσα πολλά πράγματα που με εμποδίζουν.
0 1 2 3 4
2. I check things more often than necessary. Ελέγχω τα πράγματα πιο συχνά από ότι είναι απαραίτητο.
0 1 2 3 4
3. I get upset if objects are not arranged properly. Αναστατώνομαι εάν τα πράγματα δεν είναι σωστά τακτοποιημένα.
0 1 2 3 4
4. I feel compelled to count while I am doing things. Νιώθω την ανάγκη να μετράω τη στιγμή που κάνω πράγματα.
0 1 2 3 4
5. I find it difficult to touch an object when I know it has been touched by strangers or certain people. Το βρίσκω δύσκολο να ακουμπήσω ένα αντικείμενο όταν ξέρω ότι το έχουν ακουμπήσει ξένοι ή ορισμένοι άνθρωποι.
0 1 2 3 4
6. I find it difficult to control my own thoughts. Το βρίσκω δύσκολο να ελέγχω τις δικές μου σκέψεις.
0 1 2 3 4
7. I collect things I don’t need. Συγκεντρώνω πράγματα που δε χρειάζομαι.
0 1 2 3 4
8. I repeatedly check doors, windows, drawers, etc.Ελέγχω επανειλημμένα πόρτες, παράθυρα, συρτάρια κτλ.
0 1 2 3 4
9. I get upset if others change the way I have arranged things. Αναστατώνομαι εάν οι άλλοι αλλάξουν τον τρόπο με τον οποίο έχω τακτοποιήσει τα πράγματα.
0 1 2 3 4
10. I feel I have to repeat certain numbers.Νιώθω ότι πρέπει να επαναλαμβάνω συγκεκριμένους αριθμούς.
0 1 2 3 4
11. I sometimes have to wash or clean myself simply because I feel 0 1 2 3 4
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contaminated. Μερικές φορές πρέπει να πλυθώ ή να καθαριστώ απλά επειδή νιώθω μολυσμένος.
12. I am upset by unpleasant thoughts that come into my mind against my will. Αναστατώνομαι από δυσάρεστες σκέψεις που έρχονται στο μυαλό μου παρά τη θέλησή μου.
0 1 2 3 4
13. I avoid throwing things away because I am afraid I might need them later. Αποφεύγω να πετάω πράγματα επειδή φοβάμαι ότι μπορεί να τα χρειαστώ αργότερα.
0 1 2 3 4
14. I repeatedly check gas and water taps and light switches after turning them off. Ελέγχω επανειλημμένα το μάτι της κουζίνας, το θερμοσίφωνα και τις βρύσες και τους διακόπτες του φωτός αφού τους έχω κλείσει.
0 1 2 3 4
15. I need things to be arranged in a particular order. Χρειάζομαι τα πράγματα να είναι τακτοποιημένα με συγκεκριμένη σειρά.
0 1 2 3 4
16. I feel that there are good and bad numbers. Πιστεύω ότι υπάρχουν καλοί και κακοί αριθμοί.
0 1 2 3 4
17. I wash my hands more often and longer than necessary. Πλένω τα χέρια μου πιο συχνά και για μεγαλύτερη διάρκεια από ότι είναι απαραίτητο.
0 1 2 3 4
18. I frequently get nasty thoughts and have difficulty in getting rid of them. Συχνά μου έρχονται κακές σκέψεις και έχω δυσκολία στο να απαλλαχτώ από αυτές.
0 1 2 3 4
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