Ten year outcomes of outpatients with schizophrenia on conventional depot antipsychotics: a systematic chart review

Long-term follow-up data of patients with schizophrenia on depot antipsychotics have been few and the longest follow-up period has been up to 7 years. We carried out a systematic chart review to examine 10-year outcomes for outpatients with schizophrenia who were receiving a conventional depot antipsychotic. Maintenance of outpatient status for 10 years was considered as a favorable outcome. From the initial sample of 1587 outpatients, 90 patients who were receiving a depot antipsychotic were included in this study (mean±SD, age 44.0±13.0 years; men, N=54). Haloperidol decanoate, fluphenazine decanoate, fluphenazine enanthate, and haloperidol decanoate plus fluphenazine enanthate were used in 53 (58.9%), 29 (32.2%), seven (7.8%), and one (1.1%) patients, respectively. These depot antipsychotics accounted for 36.9% of the total antipsychotic dosage on average. Seventeen patients (18.9%) successfully maintained outpatient status for 10 years. The most frequent reason for dropout was 'hospitalization' (N=49, 54.4%), followed by 'referral to another clinic/hospital' (N=9, 10.0%) and 'side effects' (N=7, 7.8%). As only 36.9% of the chlorpromazine equivalents were administered through depot antipsychotics, it is difficult to draw any firm conclusion. Still, the data suggest that even depot antipsychotics may not sufficiently prevent relapse in the treatment of schizophrenia.