Sir Christian Kreipke, PhD, FRSC. A disease manifested in the brain that causes deviation in behavior from a set of socially acceptable norms Distinct.

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