Does the biology go around the symptoms? A copernican shift in schizophrenia paradigms

It is often assumed that if physical differences exist between the brains of people with schizophrenia and normal people then those biological differences will have caused the psychological abnormalities to occur. In this article, we challenge this view. First, we argue that the reverse case is also plausible, namely, that it is possible for the physiological differences associated with the condition to be the result of the condition and not the cause. Less contentiously, we propose that the relationship between the psychological problems and the physiology should be viewed not as a simple billiard-ball style cause-and-effect relationship but more as a reciprocal and iterative relationship where psychological effects can affect the physiology that can in turn affect the psychology. The evidence for the various physiological differences between people with schizophrenia and normals is assessed and it is concluded that these differences exist but that there is little evidence to demonstrate that all (or indeed even any), of them precede the onset of schizophrenic symptoms. Similarly, current information-processing theories can also be considered as descriptive of a psychotic state rather than causal to it. Similarities between traumatic shock and schizophrenia are discussed and it is argued that phenomena associated with trauma might need to be considered as an integral part of the psychoticʹs experience. It is also concluded that no psychological theory can deny the importance of the physiological level in schizophrenia.