Objective: It is suggested that schizophrenic patients who respond to neuroleptic medication and those who do not might differ with respect to their pathogenesis. In particular, it has been proposed that genetic factors may contribute to treatment response and/or outcome. In order to test this hypothesis, we compared the pattern of familial aggregation of schizophrenia related disorders in schizophrenic patients who are either responders (R) or nonresponders (NR) to typical neuroleptics.
Method: R (n=36) or NR (n=35) patients to typical neuroleptics and healthy controls (n=63) were recruited. At least one key informant relative of each proband was interviewed blind as to the status of the proband using the Family Interview for Genetic Studies. Morbid risk for schizophrenia and cluster A personality disorders and family loading score for schizophrenia were examined in first- and second-degree relatives of these probands.
Results: First-degree relatives of NR patients were at a significantly higher risk for schizophrenia (MR=8.84), compared, respectively, to relatives of controls (MR=1.52) or relatives of R patients (MR=2.45). The same pattern was observed in second-degree relatives. Family loading score for schizophrenia in first- and second-degree relatives was significantly higher in NR compared to R patients.
Conclusions: Schizophrenic patients who do not respond to typical neuroleptics may suffer from a more familial form of schizophrenia compared to patients who are responders.