Overview
This lecture summarizes key points about schizophrenia, including its classification, causes, symptoms, diagnosis, and treatment approaches, for quick exam revision.
Classification and Symptoms of Schizophrenia
- Schizophrenia is diagnosed if two or more symptoms are present for at least a month, with at least one positive symptom.
- Positive symptoms: hallucinations (false sensory experiences), delusions (irrational beliefs), and disorganized speech.
- Negative symptoms: avolition (lack of motivation), speech poverty, and loss of normal functioning.
Diagnosis: Reliability and Validity
- Inter-rater reliability: agreement between different clinicians.
- Test-retest reliability: same clinician gives consistent diagnosis over time.
- Validity concerns: symptom overlap with other disorders (e.g., bipolar), comorbidity, and potential misdiagnosis.
- Studies show low agreement between doctors and cultural/gender biases in diagnosis.
Biological Explanations
- Schizophrenia is polygenic (multiple genes involved) and has higher prevalence in closer relatives.
- The dopamine hypothesis: excess dopamine linked to positive symptoms, low dopamine to negative symptoms.
- Enlarged brain ventricles and low glutamate are associated with schizophrenia.
- Concordance rates: higher in monozygotic twins than dizygotic, but not 100%, suggesting environmental roles.
Psychological Explanations
- Family dysfunction (e.g., double bind, high expressed emotion) is linked to higher relapse rates.
- Cognitive explanations: faulty attention and metarepresentation processes lead to symptoms.
- Evidence suggests both family environment and faulty cognition play roles, but socially sensitive.
Biological Treatments
- Typical antipsychotics (first generation) reduce positive symptoms but have severe side effects.
- Atypical antipsychotics (second generation) treat both positive and negative symptoms with fewer side effects.
- Drug therapies are effective but work best in combination with psychological therapies.
Psychological Treatments
- Cognitive Behavioural Therapy (CBT) targets dysfunctional thought patterns and challenges delusions.
- Family therapy educates families and reduces relapse, improving patient outcomes.
- Token economies use rewards to manage negative symptoms in institutional settings.
The Interactionist/Diathesis-Stress Model
- Schizophrenia results from a combination of genetic vulnerability and environmental stressors.
- The most effective treatment combines biological (drug) and psychological (CBT, family therapy) interventions.
- Concordance studies and adoption studies support the interactionist model.
Key Terms & Definitions
- Positive Symptoms — Additions to normal experience (e.g., hallucinations).
- Negative Symptoms — Loss of normal abilities (e.g., avolition).
- Inter-rater Reliability — Agreement between clinicians on diagnosis.
- Dopamine Hypothesis — Theory linking dopamine imbalance to schizophrenia.
- Expressed Emotion — Family environment with high criticism or hostility.
- Token Economy — Behavioral therapy using rewards.
- Diathesis-Stress Model — Interaction of genetic vulnerability and environmental stress in disorder development.
Action Items / Next Steps
- Review full-length videos or textbook for detailed explanations.
- Test knowledge using flashcards or the recommended app.
- Complete assigned readings on schizophrenia diagnosis, treatments, and theories for next class.