sir christian kreipke, phd, frsc. a disease manifested in the brain that causes deviation in...
TRANSCRIPT
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