Elevated presynaptic striatal dopaminergic function is a well-known feature of schizophrenia. However, the relationship between elevated dopamine and response to dopamine-blocking antipsychotic treatments is still unclear. The authors of this study tested the hypothesis that response to antipsychotic treatment would be related to the severity of presynaptic dopamine dysfunction, using [18F]-DOPA uptake positron emission tomography (PET). Schizophrenic patients who were known to respond to antipsychotic treatment were compared with treatment-resistant patients and healthy volunteers.
The results suggested that in a subgroup of schizophrenics, antipsychotic treatment may be ineffective because these patients do not exhibit the elevation in dopamine synthesis capacity that is classically associated with the disorder. The authors suggest that this may reflect a different underlying pathophysiology or a differential effect of antipsychotic treatment.
Demjaha A, Murray RM, McGuire PK, Kapur S, Howes OD: Dopamine Synthesis Capacity in Patients with Treatment-Resistant Schizophrenia. Amer. J. Psychiatry 169: 1203-1210 (2012).
