OBJECTIVE: To characterize better the length of time required for the
onset of improvement during clozapine treatment for refractory
schizophrenia, the author reanalyzed data from a naturalistic outcome
study. METHOD: Medical records of 100 adults sequentially treated with
clozapine in a state hospital were reviewed through 18 months. A priori
criteria were used to categorize change in a measure of global social
functioning. RESULTS: Of 73 patients who met the criteria for at least some
improvement during clozapine treatment, 55 demonstrated initial improvement
within 6 months, and the remainder demonstrated improvement by month 11.
Response at 3 months was significantly correlated with outcome at 18
months. CONCLUSIONS: Gross social improvement as measured in this study is
likely to lag behind more sensitive indicators of clinical response. This
study supports the notion that initial response to clozapine occurs within
the first few months of treatment.