Introduction to Psychiatry

INTRODUCTION TO PSYCHIATRY Sir Christian Kreipke, PhD, FRSC

WHAT IS A PSYCHIATRIC CONDITION? A disease manifested in the brain that

causes deviation in behavior from a set of socially acceptable norms

Distinct from psychological conditions in that a supposed somatic pathotrajectory exists

Can be induced by genetic conditions, damage to the brain, or environmental conditions

Abnormal

Normal

Criminal

Psychiatric

MEDICAL ANTHROPOLOGICAL PERSPECTIVE

Most societies have there own set of codes for “normal” and “abnormal” behavior

These closely defined norms may or may not overlap Examples:

ADHD does not exist in Cuba Infanticide is culturally acceptable in China Cannibalism is still practiced in certain tribes of the South

Pacific region Female circumcision Tattoos Etc.

COMMON PSYCHIATRIC DISORDERS Schizophrenia (10%) Turret's Syndrome (~1:10,000) Bipolar (~1:5,000) ADHD (~15-20%) Autism (~15%) Depression (~20%) Obsessive Compulsive disorder (~5%)

SCHIZOPHRENIA Characterized by a whole host of conditions According to the DSM-IV, if the subject

exhibits 2 or more of the following they have a probability of schizophrenia: Auditory/visual hallucinations Asocial behavior Aggressive behaviors Confusion Negative affect “split personality disorder”

SCHIZOPHRENIA Possible biological cause

Abnormal development in striatum, medial temporal lobe, and/or corpus collosum

Hyperdopaminergic and hypoglutamatergic drive to the striatum

More generally, disrupted dopaminergic system

SCHIZOPHRENIA Treatment:

Haldol (D2 antagonist) Clorpromazine/clozapine (atypical

antipsychotic which binds D3/4 system) PROBLEM:

Patient’s behavior can be severely altered

BIPOLAR Characterized by multiple personality

types (2 or more) and/or by severe shifts in mood (manic-depression)

BIPOLAR Possible biological cause:

Abnormal development of striatum, corpus collosum, and/or prefrontal cortex

Disrupted glutamatergic drive to the cortex

BIPOLAR Treatment:

Lithium (mood stabilizer) Mode of action? UNKNOWN

ADHD Characterized by lack of ability to focus

on single task and/or hyperactivity associated with lack of focus

ADHD Possible biological causes:

Dysfunctional dopaminergic system particularly in the striatum

ADHD Treatment:

Dopaminergic drugs (amphetamine derivatives, psychostimulants)

How do they work? Deplete the dopamine system quickly.

Recovery time squelches dopamine drive and quiets overactive behaviors. Specifically they cause dopaminergic neurons to release dopamine and block reuptake via blocking the DAT

DEPRESSION Characterized by chronic negative

affect usually not correlated with a particular event. CAVEAT: clinical depression may be triggered by environmental cue.

Emphasis on chronic!!!

DEPRESSION Possible biological cause:

Disrupted serotonergic drive to cortex

DEPRESSION Treatment:

SSRIs. Selectively prevent serotonin reuptake through the serotonin transporter, thus allowing more to remain in the synaptic cleft.

OCD Characterized by repetitive often self-

injurous behaviors

OCD Possible biological cause

Recapitulates that of depression

OCD Treatment:

SSRIs most effective Cognitive behavioral therapy

OTHERS Autism, turret’s and a host of other

pathological conditions sadly have unknown biological pathotrajectories and hence treatment is often laborious and inconclusive