Physiological Psychology 41363
Outline 13
I. Review of neurological disorders
Mental Disorders
I. Psychoses vs neuroses
A. Schizophrenia - bizarre disturbances in thoughts and feelings
1. Affects about 1% of the world's population
2. Two types of symptoms
a. Positive symptoms - abnormal symptoms that are present
b. negative symptoms - absence of normal behaviors
3. Causes
a. Genetics - adoption studies
- twin studies - 4 times higher concordance rate for identical twins than dizygotic
b. Biochemical causes - positive symptoms
-Dopamine hypothesis
-chlorpromazine - blocks dopamine receptors
-nucleus accumbens - drugs that block DA receptors only in the nucleus accumbens
result in decreased schizo symptoms
-why would DA be responsible? - reward
c. brain damage - negative symptoms of schizophrenia
-ventricles are twice as big in schizo patients
-differences in organization of the hippocampus
-what causes the brain damage -virally induced:
-latitude effect
-seasonality effect
B. Major affective disorders - feelings of mania or depression that are not justified by events
in their lives
1. types of depression
-reactive - following an event that saddens us
-endogenous - intrinsic characteristic
2. Two types of major affective disorders
a. bipolar disorder - alternating periods of mania and depression - mania lasts usually
days to weeks and then the periods of depression last months: equal numbers of
men and women
b. unipolar depression - unremitting or episodic: 2 to 3 times more common in women
- risk of death by suicide: 10% of depressed individuals commit suicide
-lower concentrations of serotonin in the brain and higher levels of circulating
cortisol
3. Genetics - concordance rate of monozygotic twins is 69% while for dizygotic is only
13%
4. Treatments
a. monoamine oxidase inhibitors - MAO inhibitors:
-monoamine hypothesis of depression - focus on NE and serotonin
b. tricyclic antidepressants - inhibit the reuptake of serotonin and NE by terminal buttons
c. electroconvulsive therapy (ECT) - has very rapid effects
d. lithium - used to treat bipolar disorder - very rapid: works best when administered
during a manic phase
5. Depression and sleep
a. difficulty falling asleep: decreased slow wave sleep: earlier REM period
b. treating depression with sleep deprivation 1.total sleep deprivation - immediate increases in mood for about 2/3 of all
depressives
2. partial sleep deprivation - selective deprivation of REM sleep
c. seasonal affective disorder - treated with phototherapy - might act through melatonin
6. Depression and the HPA axis
-high levels of cortisol have also been found in hospitalized depressed patients:
-dexamethasone suppression test
C. Anxiety disorders persistent unrealistic and unfounded fear
1. Panic disorder - 1-2% of the population and twice as many women as men
-anticipatory anxiety can lead to agoraphobia
-causes - some hereditary evidence: can be triggered with injections of lactic acid or
breathing carbon dioxide
-treated with benzodiazepine
2. Obsessive compulsive disorder -obsessions - inappropriate thoughts that will not leave
-compulsions - inappropriate behaviors that you can't keep from performing
-1-2% of the population and females are slightly more likely to have
a. causes - some genetic evidence - associated with Tourette's syndrome
-damage to the basal ganglia and the areas around the cingulate gyrus and the
prefrontal cortex
b. treatment
-knocking out the cingulate bundle
-serotonin agonists: blockers of 5-HT reuptake