What Is the Efficacy of Conventional Antipsychotics for Prevention of Relapse and Recurrence of Positive Symptoms?
The Baldessarini et al. (1990) and Davis et al. (1993) reviews find overwhelming evidence that conventional antipsychotic agents reduce the risk of relapse of the positive symptoms of schizophrenia. Based on 44 placebo-controlled studies of antipsychotics with a total of 3,939 subjects and an average followup period of 9.8 months, Baldessarini et al. (1990) found that the rate of symptom exacerbation on placebo was 55 percent versus 14 percent on active medication (mean daily dose = 397 CPZ equivalents), a 3.9-fold overall sparing of relapse attributable to medication. Davis and colleagues (1993) evaluated 35 randomized double-blind studies with 3,720 patients and a minimum of 6 weeks of followup (most in the 4- to 6-month range) and estimated relapse rates to be 55 percent on placebo versus 21 percent on active medication, a highly significant difference. In interpreting this substantial impact, both reviewers point out several limitations to their research: (1) selection design for t
