Although studies indicated that the atypical drugs are similar to the conventional drugs in reducing psychotic symptoms and produce few neurologic effects, the evidence of their superior efficacy has been neither consistent nor robust,3-8 with the exception of clozapine, which repeatedly has been effective in patients whose condition is refractory to treatment with other types of agents but has severe side effects that limit its use.9-11 The newer agents appear more efficacious than conventional drugs in reducing negative symptoms (e.g., lack of emotion, interest, and expression), possibly owing to the absence of extrapyramidal symptoms12 or other secondary causes of negative symptoms (e.g., depression) rather than to direct therapeutic effects.13 The results of studies of the effects of treatment on cognitive impairment and mood symptoms have been inconclusive.14,15 The ability of atypical agents to prevent relapse and their effects on social and vocational functioning, quality of life, long-term outcome, and the caregivers' burden have been incompletely explored.8,12,16