PSYC 415 -- Dr. King -- Terms for schizophrenia Positive vs. Negative Symptoms positive symptoms - hallucinations, delusions, thought disorder, mannerisms negative symptoms - flattened affect, apathy, anhedonia, poverty of speech, stupor, catatonia, social withdrawal, deterioration Cognitive Symptoms - difficulty in sustaining attention, low psychomotor speed, learning and memory deficits, poor abstract thinking, poor problem solving Statistics - 1% lifetime risk First Diagnosis - most commonly during adolescence, esp. in men Course - negative symptoms first (prodromal), followed by cognitive symptoms, followed sometimes years later by positive symptoms Rule of Quarters Schizophrenia and Public Health Heritability twin studies - MZ twins are more likely to be concordant than DZ twins adoption studies - more likely correlated with biological than adoptive family morbid risk - Gottesman & Bertelsen (1989); be sure you understand this Congenital Factors birth complications maternal viral infections Methylation Theory - no longer really considered seriously Dopamine Theory drugs that alleviate symptoms of schizophrenia are DA receptor blockers chlorpromazine (Thorazine) - introduced in 1956 side effects - Parkinsonism and tardive dyskinesia amphetamine-induced stereotypy atypical antipsychotics - e.g., clozapine dopamine pathways nigrostriatal system - substantia nigra to basal ganglia mesolimbic system - ventral tegmental area to nucleus accumbens, amygdala, and prefrontal cortex potency of drugs is strongly correlated with drug's ability to block DA receptors amphetamine psychosis - LSD does not produce psychosis DA receptor studies - at autopsy and by PET scanning functional imaging studies Dopamine Theory: Problems about 1/3 of patients who get DA receptors blockers are nonresponders onset of drug response is delayed by 2-3 weeks tardive dyskinesia is not accompanied by tardive schizophrenia Schizophrenia as a Neurological Disorder soft neurological signs general brain atrophy shows up as enlarged ventricles loss of cortical gray matter cell loss and disorganization in the hippocampus hypofrontality - Wisconsin Card Sort Test possibility of a viral infection causing brain damage Epidemiology seasonality effect population density prenatal malnutrition prenatal maternal stress obstetric complication The Emerging Story - abnormal brain development is strongly implicated esp. in the dorsolateral prefrontal cortex hypofrontality esp. important in development of negative symptoms working memory impairment associated with changes in DA activity in the nuc. accumbens PCP and ketamine So Here's What Happens Clozapine, etc.