The expert consensus guideline series: adherence problems in patients with serious and persistent mental illness

OBJECTIVES: Poor adherence to medication treatment can have devastating consequences for patients with mental illness. The goal of this project was to develop recommendations for addressing adherence problems to improve patient outcomes.
METHODS: The editors identified important topics and questions concerning medication adherence problems in serious mental illness that are not fully addressed in the literature. A survey was developed containing 39 questions (521 options) asking about defining nonadherence, extent of adherence problems in schizophrenia and bipolar disorder, risk factors for nonadherence, assessment methods, and interventions for specific types of adherence problems. The survey was completed by 41 (85%) of the 48 experts to whom it was sent. Results of the literature review and survey were used to develop recommendations for assessing and improving adherence in patients with serious mental illness.
RESULTS: ASSESSING ADHERENCE: The experts endorsed percentage of medication not taken as the preferred method of defining adherence, with 80% or more of medication taken endorsed as an appropriate cut-off for adherence in bipolar disorder and schizophrenia. Although self- and physician report are the most common methods used to assess adherence in clinical settings, they are often inaccurate and may underestimate nonadherence. The experts recommend that, if possible, clinicians also use more objective measures (e.g., pill counts, pharmacy records, and, when appropriate, serum levels such as are used for lithium). Use of a validated self-report scale may help improve accuracy.
SCOPE OF THE PROBLEM: The majority of the experts believed the average patient with schizophrenia or bipolar disorder in their practices takes only 51%-70% of prescribed medication. FACTORS ASSOCIATED WITH NONADHERENCE: The experts endorsed poor insight and lack of illness awareness, distress associated with specific side effects or a general fear of side effects, inadequate efficacy with persistent symptoms, and believing medications are no longer needed as the most important factors leading to adherence problems in schizophrenia and bipolar disorder. The experts considered weight gain a side effect that is very likely to lead to adherence problems in patients with schizophrenia and bipolar disorder; sedation was considered a more important contributor to adherence problems in bipolar disorder than schizophrenia. The experts rated persistent positive or negative symptoms in schizophrenia and persistent grandiosity and manic symptoms in bipolar disorder as the most important symptomatic contributors to adherence problems in these illnesses.
INTERVENTIONS: It is important to identify the specific factors that may be contributing to a patient's adherence problems in order to customize interventions to target those problems. Multiple problems may be involved, requiring a combination of interventions.
CONCLUSIONS: Adherence problems are complex and multidetermined. The experts recommended customized interventions focused on the underlying causes.