6 Despite the demonstrated efficacy of antipsychotic drugs (APDs)

in short-term placebo-controlled clinical trials, long-term outcomes frequently remain unsatisfactory. The largest NIH-supported clinical trial of antipsychotic agents conducted to date revealed that both first-generation antipsychotics (FGAs) and second -generation antipsychotic (SGA) agents have limited long-term effectiveness, largely due to high rates of discontinuation (-75% discontinuation within 18 months).7 Similar results were obtained in two large-scale European effectiveness trials.8,9 In each of these trials, Inhibitors,research,lifescience,medical clinically significant side effects were noted in the majority of patients, Inhibitors,research,lifescience,medical and tolerability was the primary cause of at least 20% of all drug discontinuations. The high likelihood of medication discontinuation has substantial clinical and economic implications, as treatment nonadherence is perhaps the single strongest predictor of relapse and rehospitalization.10 Patients who have discontinued APDs may be as much as five times more likely to relapse as medicated patients.11 Moreover, nearly half of rehospitalization costs in SCZ may be accounted for by medication nonadherence.12 In addition Inhibitors,research,lifescience,medical to the effectiveness trials cited above, many observational studies and

controlled trials have presented evidence that perceived side-effect burden frequently leads to both poor attitudes towards medications and a tendency towards discontinuation, nonadherence, and partial adherence.13,14 Although side effects are highly prevalent, there Inhibitors,research,lifescience,medical is also substantial variability in liability to clinically significant or intolerable adverse events.15 Consequently, understanding and predicting liability to side effects may be an effective Inhibitors,research,lifescience,medical strategy- to improve prognosis in schizophrenia. Antipsychotic-induced side effects FGAs were most commonly

associated with neuromuscular side effects, including the potentially irreversible movement disorder, tardive dyskinesia (TD).16 In large cohort studies, TD has been shown to affect at least one in five, and perhaps as many as one in three, patients treated chronically with FGAs.17 New onset (incidence) of TD is approximately Phosphatidylinositol diacylglycerol-lyase 3% to 5% per year of treatment, and these rates are increased as much as fivefold in elderly patients.18 In addition to physical discomfort and social stigma, presence of TD has been associated with reduced quality of life, increased psychopathology, and increased mortality rates.19 Even at low doses and/or intermittent treatment schedules, the high prevalence and morbidity associated with TD was the primary impetus for the PD98059 mw promotion of SGAs as preferred firstline treatment, at least in the United States.15,20 Although use of SGAs is not entirely free from TD risk, incidence and rates are as much as 80% lower for SGAs compared with FGAs.