Dopaminergic Balance and Subtypes of Schizophrenia

Several attempts have been made to relate subtypes of schizophrenia to dopaminergic status. For example, Crow's hypothesis states that Type I schizophrenia is characterised by positive symptoms, increased activity of the dopaminergic system, good response to neuroleptics, and no brain structural changes; and Type II by negative symptoms, reduced dopaminergic activity, poor response to neuroleptics, and brain structural changes. Testing of this hypothesis has, however, been inconclusive, and it seems more likely that both types are inter-related.