Interactionist Approach

Interactionist approach

Explanation that schizophrenia results from both biological vulnerability and environmental stress.

Diathesis–stress model

States that a genetic or biological predisposition (diathesis) interacts with stressors to trigger schizophrenia.

Diathesis definition

A vulnerability or predisposition, usually genetic or biological.

Stress definition

Any environmental experience that triggers the onset of schizophrenia.

Genetic diathesis

Schizophrenia strongly linked to genetic factors such as multiple risk genes.

Biological diathesis examples

Genes affecting dopamine or glutamate, prenatal infection, brain abnormalities.

Environmental stressors

Family conflict, trauma, abuse, high expressed emotion, drug use (especially cannabis).

Tienari adoption study

Found schizophrenia most likely in individuals with genetic vulnerability AND high-stress adoptive families.

Cannabis as a stressor

Cannabis use increases risk by affecting dopamine; not sufficient alone to cause schizophrenia.

Modern diathesis–stress model

Diathesis can include genetic, psychological or trauma-based vulnerability.

Childhood trauma

Physical, emotional or sexual abuse increases likelihood of schizophrenia.

Urban living stress

High population density and social stress linked to increased incidence.

Interactionist treatment approach

Combines antipsychotic medication with psychological therapies.

Medication role

Reduces biological symptoms and allows engagement in therapy.

CBT role

Helps challenge irrational beliefs and improve coping.

Family therapy role

Reduces stress and expressed emotion in the home environment.

Strength: holistic explanation

Considers both nature (biology) and nurture (environment).

Strength: strong research support

Tienari’s adoption study directly supports the diathesis–stress model.

Strength: effective treatment

Combined therapy more effective than medication or therapy alone.

Limitation: unclear mechanisms

Exact way genes and stress interact is not fully understood.

Limitation: oversimplification

Schizophrenia likely involves many interacting factors beyond simple diathesis and stress.

Limitation: treatment causation fallacy

Just because combined treatment works does not prove interactionist cause.

Overall conclusion

Best explanation of schizophrenia integrates biological, psychological and social factors.