PSYC 304: Psychopathology

positive symptoms of schizophrenia

hallucinations (auditory), delusions, disordganized thinking, excited motor behaviour

negative symptoms of schizophrenia

slow speech/thought, emotional/social withrawal, blunted affect

cognitive impairments of schizophrenia

memory problems, poor attention, difficulty planning, reduced social cognition

heritability of schizophrenia

partly heritable, MZ twin concordance = 50%

biological indicators of schizophrenia

no single causal gene, but some include: DISC1 and synaptic rearrangement

• genetic vulnerability + stress = increased risk

endophenotypes of schizophrenia

fast eye movements

epigenetic factors of schizophrenia

paternal age, maternal stress (eg; influenza, low birth weight, hypoxia)

environmental factors of schizophrenia

adolescent transitions, city living, time of year

brain differences in schizophrenia

• enlarged ventricles

• smaller hippocampus/amygdala

• hippocampal pyramidal cell disorganization

• abnormal limbic network activity

• altered corpus callosum

• loss of frontal lobe matter, reduced metabolism

dopamine hypothesis

excess DA D2 receptor activity leads to positive symptoms of schizophrenia

evidence of dopamine hypothesis

amphetamines, which are agonists for DA, produce side effects similar to positive symptoms

• antipsychotics to stop these side effects block D2 receptors

limitations of dopamine hypothesis

slow symptom improvement, even though antipsychotics work within hours

• some people don’t respond to antipsychotics

glutamate hypothesis of schizophrenia

schizophrenia is caused by underactive glutamate receptors, which may account for hypofrontality

evidence of glutamate hypothesis

PCP and ketamine, which are both glutamate antagonists, mimic the positive, negative and cognitive symptoms of schizophrenia

symptoms of depression

unhappy mood, loss of interest, low energy, poor concentration, anhedonia

DSM criteria of depression

at least 5 symptoms for 2+ weeks, disrups daily living and is not linked to other causes

depression and suicide

depression may lead to suicide

• if first attempt is averted, chance of future suicide attempts are greatly reduced

heritability of depression

higher concordance rate in MZ than DZ twins

• no single gene, but some D2 receptor gene subsets are linked to depression

• genetic screening may predict individual’s responses to medical treatments

prefrontal cortex and amygdala (depression)…

have increased blood flow

parietal, posterior temporal, anterior cingulate (depression)…

have decreased blood flow

hippocampal volume in depression

reduced volume and activation during memory tasks

non-drug treatments of depression

• ECT

• rTMS

• vagal nerve stimulation

• DBS

• exercise

• CBT

pharmacological treatments of depression

• MAO inhibitors

• SSRI/SNRIs

• ketamine

• psychedelics

sleep with depression

• less stage 3

• more stage 1-2

• earlier REM onset

REM sleep and depression

shortened REM sleep correlates with severity

• this may impair negative emotion processing - REM is involved with processing emotions/consolidating memories

• if shortened, individual processes emotions when awake instead