Adverse effects of antipsychotics as outcome measures

BACKGROUND: Antipsychotic drugs are associated with adverse effects that can lead to poor medication adherence, stigma, distress and impaired quality of life. AIMS: To review the use of adverse effects of antipsychotic drugs as outcome measures, with a particular emphasis on methodological issues. METHOD: Review of data on adverse effects from sources including randomised controlled trials (RCTs), post-marketing surveillance and naturalistic studies. RESULTS: All have advantages and disadvantages and the best overview comes from considering all sources of data together. Adverse effects are inconsistently reported, hampering cross-study comparisons. Many outcome measures lack clinical meaning. In both naturalistic studies and RCTs adverse effects often account for less treatment discontinuation than lack of efficacy. CONCLUSIONS: Standardisation in the reporting of adverse effects is needed. Patients' subjective experience of medication should be given more consideration. Total discontinuation rates provide a useful global outcome measure that incorporates tolerability and efficacy as well as patient and clinician viewpoints. Patients should be informed of common side-effects prior to treatment and monitored for their occurrence during treatment.