Schizophrenia

Onset - late adolescent and early adulthood

Symptoms- delusions - inappropriate affect- hallucinations- incoherent thought- odd behavior (extreme - catatonia)

Causes

Genetic - some roleconcordance in identical twins - 45%

Suceptibility idea- environment plays some role- flu (or related virus) in 2nd trimester?- the latitude effect- the seasonality effect (born in feb to may - slight increase)

Dopamine hypothesis

Chlorpromazine - surgical antihistamine

- blocks DA receptors- neuroleptics

Refinement - D2 receptors most important

too much dopamine - schizophrenic behaviorBlock dopamine - schizophrenia gets better

Too much dopamine? - no evidencetoo many receptors - some evidence

(but changes due to treatment?)- more sensitive to dopamine

- ventral tegmental area - just above S.N. (mesocortical - mesolimbic system)- nucleus accumbens - receives dopamine from VTA

- perhaps screwed up systems rewards bad thoughts and behaviors- process gets worse and worse

- or VTA -> prefrontal area -> Limbic system- damage to prefrontal cortex (which INHIBITS Limbic system)- hypoactivity of prefrontal cortex (PET Studies)- hyperactivity in limibc system (goes wild - no inhibition)

- amygdala - emotion - increased activity of dopamine system in temporal lobe

** positive symptoms & negative mental symptoms

** negative physical symptoms - the other dopamine system - basal ganglia- brain damage - enlarged ventricles

Affective Disorders

Depression-Reactive-endogenous (unipolar) - 6%

-- twice as high in women (?)-- 10% suicide

Mania (bipolar disorder)- about 1%- no sex difference

Causal Factors

Genetic- concordance in identical twins - 60%

(origin - organic vs experience?)

- why gender difference?- genetic? (X chromosome?)- experience/behavioral?

Experience- stress

- acute (precipitating factor/ trigger)- sustained (?)

Brain changes- lower volume of prefrontal cortex- fewer glial cells

- fewer and smaller neurons- enlarged ventricles (means?)

- cerebellum & basal ganglia?

- due to depression or the drug treatment

Amygdala involvement?- too active?- involved in negative emotion

Treatment- monoamine oxidase inhibitors (MAOI)

- agonist effect

- problem - tyramine (cheese, wine)- usually metabolized by MAO- if not, raises blood pressure - stroke

- tricyclics- block reuptake

- serotonin- norepinephrine

Lithium- bipolar disorder- much faster, but low compliance- effects serotonin system? - receptors

SSRI’s- here and anxiety disorders- effective on lots of things (previously psychther)- few side effects??

ECT - Shock therapy- still used- also magnetic stimulation

Anxiety disorders- generalized- phobic- panic- obsessive compusive

Cause- genetic component- experience - more individual/more closely linked

Treatment

Benzodiazepines- 10% of adults taking them??- GABA agonist (increase binding)

Serotonin agonists- MAOI, TriC, SSRIs- anxiolytic

Tourette’s Syndrome

Tics - motor, vocal, simple, complex

Treatment - dopamine receptor blockers (neuroleptic)

-suggests basal ganglia is involved (motivation for action)-- also limbic cortex (emotional/control)

Exam 5 - MondayTerm projects - Friday

Have a good summer.