Abnormal Psychology: Schizophrenia and Psychotic Disorders

Schizophrenia and Other Psychotic Disorders

Prevalence and Epidemiology

• Lifetime prevalence of schizophrenia: just under 1%
• Age of onset: 18-30 years old, more common and severe in men
• Risk factors: older father, parent in dry cleaning business, first- and second-generation immigrants (especially from black Caribbean and African countries)
• Schizophrenia tends to "run in families" - 10% prevalence in first-degree relatives and 3% in second-degree relatives

Clinical Picture

• Delusions: fixed, firm beliefs despite clear contradictory evidence, e.g. being controlled by external agents, private thoughts being broadcast
• Hallucinations: sensory experiences without external stimuli, most common in auditory modality
• Disorganized speech: disorder of thought form, using language in unconventional ways
• Disorganized behavior: impairment of goal-directed activity, e.g. catatonia, unusual dress, and behavior
• Negative symptoms: absence or deficit of normally present behaviors, e.g. reduced expressive behavior, avolition

Other Psychotic Disorders

• Schizoaffective disorder: features of schizophrenia and severe mood disorder
• Schizophreniform disorder: schizophrenia-like psychoses lasting at least 1 month but less than 6 months
• Delusional disorder: delusional beliefs with otherwise normal behavior
• Brief psychotic disorder: sudden onset of psychotic symptoms or disorganized speech or catatonic behavior

Genetic and Biological Factors

• Genetic factors: schizophrenia tends to "run in families", higher concordance rates in identical twins
• Molecular genetics: candidate genes involved in processes believed to be aberrant in schizophrenia
• Endophenotypes: discrete, stable, and measurable traits thought to be under genetic control
• Prenatal exposures: viral infection, rhesus incompatibility, and pregnancy and birth complications
• Interaction between genes and environment: genetic liability may predispose individuals to suffer more from environmental factors

Brain Abnormalities

• Neurocognition: cognitive impairment is a core feature of schizophrenia, lower IQ may be a risk factor
• Social cognition: impaired recognition, thinking, and response to social information
• Loss of brain volume: patients with schizophrenia have enlarged brain ventricles, progressive brain deterioration
• Affected brain areas: reductions in frontal and temporal lobe volume, white matter problems, and impaired brain functioning

Psychosocial and Cultural Aspects

• Family environment: adverse family environments have little consequence if child is not at genetic risk for schizophrenia

• Cultural factors: schizophrenia may be triggered or exacerbated by cultural and social factors### Psychosocial and Cultural Aspects of Schizophrenia

• Expressed emotion (EE) is a measure of the family environment based on how a family member speaks about the patient during a private interview with a researcher.

• Three main elements of EE: criticism, hostility, and emotional overinvolvement (EOI).

• High-EE home environment more than doubles the chance of a relapse, especially for chronically ill patients.

• Researchers are still trying to understand how EE affects the brain.

Urban Living and Schizophrenia

• Children who spend the first 15 years of life in an urban setting are 2.75 times more likely to develop schizophrenia than those in rural settings.
• If everyone lived in relatively rural settings, the number of schizophrenia cases could decrease by 30%.

Immigration and Schizophrenia

• Recent immigrants have a much higher risk of developing schizophrenia.
• There is no evidence that this can be explained by cultural misunderstandings.
• Immigrants with darker skin have a much higher risk of developing schizophrenia than those with lighter skin.
• Healthy people who feel discriminated against are more likely to develop psychotic symptoms than healthy people who do not perceive any discrimination.

Cannabis Use and Abuse

• People with schizophrenia are twice as likely to smoke cannabis as people in the general population.
• Cannabis may accelerate the progressive brain changes that seem to go along with schizophrenia.
• Patients with schizophrenia who also use cannabis show more loss of gray matter over the course of a 5-year follow-up than patients who do not use cannabis or healthy controls.

Diathesis-Stress Model of Schizophrenia

• Biological factors play a role in schizophrenia, including genetic predispositions shaped by environmental factors such as prenatal exposures, infections, and stressors.
• No simple answer to what causes schizophrenia; genetics and environment combine in such a way that brain pathways develop abnormally.
• Nongenetic risk factors for schizophrenia include older father, virus exposure, obstetric complications, urban upbringing, head injury, cannabis use, and migrant status.

Clinical Outcome and Treatment of Schizophrenia

• Around 38% of patients have a favorable outcome and can be thought of as being recovered 15 to 25 years after development of the disorder.
• Around 12% of patients need long-term institutionalization.
• Around one-third show signs of continued negative symptoms.

Pharmacological Approaches

• First-generation antipsychotics block the action of dopamine.
• Second-generation antipsychotics have fewer extrapyramidal symptoms.
• Researching the role of estrogen may provide new treatment options.

The Patient's Perspective and Other Approaches

• Not all patients benefit from antipsychotic medications.
• May show clinical improvement but still need help.
• Side effects may lead patients to discontinue taking the medication.
• Some patients may try to avoid taking medications because, to them, needing to take medications confirms that they are mentally ill.
• Case management, family therapy, psychoeducation, social-skills training, cognitive remediation, cognitive-behavior therapy, and exercise may also be useful in treating schizophrenia.

Learn about the prevalence and symptoms of schizophrenia, as well as other psychotic disorders and their differences. Explore the genetic and biological risk factors and more.