Discuss one or more explanations for schizophrenia 16 marks

One biological explanation for schizophrenia is the dopamine hypothesis. It suggests that schizophrenia is linked to abnormal dopamine activity in the brain. High dopamine activity in the subcortical areas, such as the mesolimbic pathway, is associated with positive symptoms like hallucinations. Conversely, low dopamine activity in the prefrontal cortex is linked to negative symptoms like avolition. More recent versions of the hypothesis also include the role of glutamate and serotonin, suggesting a more complex neurochemical interaction.

Another biological explanation is genetic. Schizophrenia appears to run in families, and studies of twins and adoption show a genetic link. For instance, Gottesman (1991) found that the concordance rate for schizophrenia is about 48% in monozygotic twins, compared to 17% in dizygotic twins. Research has also identified candidate genes, such as PCM1 and PPP3CC, and suggested that schizophrenia is polygenic, meaning it involves many genes.

Psychological explanations include family dysfunction. One example is the double-bind theory, which suggests that receiving contradictory messages from caregivers in childhood can contribute to the development of schizophrenia. Another is expressed emotion (EE), where families are highly critical or emotionally over-involved, potentially increasing the risk of relapse in diagnosed individuals.

One strength of the biological explanation is that it is supported by research evidence.
Leucht et al. (2012) conducted a meta-analysis and found that antipsychotic drugs, which reduce dopamine activity, are significantly more effective than placebos in reducing symptoms of schizophrenia. This supports the dopamine hypothesis, suggesting that dopamine plays a key role in symptom expression and can be manipulated through pharmacological treatment. However, not all patients respond to dopamine-based medications, and some atypical antipsychotics target other neurotransmitters, indicating that the dopamine explanation may be incomplete.

A limitation of both biological and psychological explanations is that they often struggle to establish causation. Changes in brain structure or family dynamics may be the result of schizophrenia, not the cause of it. This limits the internal validity of these explanations, as they may only describe correlations rather than clear causal mechanisms. Longitudinal studies can help clarify causality, but ethical and practical issues make these difficult in schizophrenia research.

A criticism of the biological explanation is that it may be too biologically reductionist.
It simplifies the complex experience of schizophrenia down to genes or neurotransmitters and ignores environmental and psychological influences. This may lead to limited treatments focused solely on medication, overlooking therapies like CBT or family therapy, which have shown effectiveness. On the other hand, biological explanations are scientifically testable and supported by objective brain imaging studies, giving them strong empirical credibility.

Another strength of using multiple explanations is that it supports an interactionist approach. The diathesis-stress model combines genetic vulnerability (nature) with environmental triggers (nurture), such as trauma or high expressed emotion. This approach reflects the complex reality of schizophrenia and has practical implications for combining drug therapy with psychological support. However, critics argue that the model can be vague in defining what constitutes "stress" and how it interacts with predisposition.