Adherence to antipsychotic medications.

Taking antipsychotic medication as prescribed is one of the best means patients have of managing psychotic symptoms and preventing relapse. Yet, for various reasons, patients may discontinue taking their medication or skip doses, either occasionally or frequently. Among patients treated with conventional neuroleptics, approximately 40% stop taking their antipsychotic medication within 1 year, and about 75% stop taking the medication within 2 years. Although adverse effects play a large role in a patient's decision to discontinue antipsychotic therapy, other factors also have an effect. Using the health belief model, clinicians can assess the relative impact of various factors on medication adherence. This model posits that adherence to treatment is determined by the patient's assessment of the perceived benefits of treatment and risks of illness versus the costs of treatment (including adverse effects such as weight gain). Other factors in the decision are barriers to adherence and cues to act (i.e., reminders to take medication). Patients who believe the risks of treatment outweigh the benefits are likely to discontinue their medication and are candidates for intervention to increase adherence.