PSYX 340 Psychological Disorders · Unit 3: Psychosis, personality and childhood · on Exam 3
3.1 Schizophrenia and psychosis
Study notes for Schizophrenia and psychosis in PSYX 340 Psychological Disorders at Montana State University: the big ideas, a worked example, common mistakes and an exam tip. The same topic has endless practice questions and flashcards in Mathub.
Big ideas
- Schizophrenia needs 2 or more of 5 symptoms for a significant part of a month (at least one of the first three): delusions, hallucinations, disorganized speech, grossly disorganized or catatonic behavior, and negative symptoms. Continuous signs must last at least 6 months, with a decline in functioning. Lifetime prevalence is about 1 in 100.
- Positive symptoms are excesses: delusions (persecution, reference, grandeur, control), hallucinations (most often auditory), formal thought disorder (loose associations, neologisms) and inappropriate affect. Negative symptoms are deficits: alogia (poverty of speech), blunted or flat affect, avolition (loss of motivation), social withdrawal. Psychomotor symptoms include catatonia.
- Related disorders by duration: brief psychotic disorder (at least 1 day but under 1 month), schizophreniform disorder (1 to 6 months), schizophrenia (6 months or more), schizoaffective disorder (a mood episode plus psychosis, with at least 2 weeks of psychosis without mood symptoms) and delusional disorder (delusions for at least 1 month without other psychotic symptoms).
- Biological causes: strong genetic risk (roughly half of identical twins share it), the dopamine hypothesis (too much dopamine activity in some pathways, supported by antipsychotics blocking D2 receptors and amphetamines worsening symptoms), glutamate, enlarged ventricles and reduced brain volume, and prenatal or viral factors.
- Psychological and sociocultural factors: the diathesis–stress model; high expressed emotion in families (criticism, hostility, over-involvement) predicts relapse; social labeling; and cultural differences in course and outcome. Double-bind theory and “schizophrenogenic mothers” have been discredited.
Worked example
For the past 3 months Lee has heard voices commenting on him and believes the TV sends him messages; he stopped attending class. He had never had symptoms before. Which diagnosis fits right now?
Show the solution
Schizophreniform disorder. The symptoms (hallucinations and delusions, with a drop in functioning) have lasted between 1 and 6 months. If they continue past 6 months the diagnosis becomes schizophrenia; under 1 month it would be brief psychotic disorder.
Common mistakes
- Equating schizophrenia with “split personality”. That is dissociative identity disorder, a different condition.
- Mixing positive and negative symptoms. Positive means added (hallucinations), negative means missing (flat affect).
- Blaming parents for causing schizophrenia. Expressed emotion predicts relapse, not onset, and the “schizophrenogenic mother” idea is discredited.
Exam tipMemorize the duration ladder (under 1 month, 1–6 months, 6+ months) and practise sorting symptoms into positive, negative and psychomotor.
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