Treatment adherence with antipsychotic medications in bipolar disorder

Abstract

Poor adherence with lithium and anticonvulsant medications has been found to be a common occurrence among individuals with bipolar disorder (estimates range between 20 and 55%) and is often associated with negative clinical outcomes (1-4). A variety of factors such as patient age, marital status, gender, educational level, symptoms, side effects of medications and comorbid substance abuse, as well as environmental factors such as psychosocial support and access to care are known to affect treatment adherence among individuals with bipolar disorder (1, 5-13). Posttraumatic stress disorder (PTSD), not infrequently Objectives: Atypical antipsychotic medications are a relatively new, increasingly prominent component of the treatment armamentarium for bipolar disorder. Information on adherence with antipsychotics among individuals with bipolar disorder in general, and atypical antipsychotics in particular, is currently quite limited. Using data from the VA National Psychosis Registry, we examined adherence with antipsychotic medications among patients with bipolar disorder (n ¼ 73,964).Methods: Antipsychotic medication adherence among veterans with bipolar disorder was evaluated using the medication possession ratio and categorizing patients into three groups: fully adherent, partially adherent and non-adherent. We compared characteristics of bipolar patients who received versus those who did not receive antipsychotic medication, and also identified predictors of poor adherence with antipsychotic medications.Results: Approximately 45% (n ¼ 32,993) of all individuals with bipolar disorder were prescribed antipsychotic medication. Individuals who were prescribed antipsychotic medications were younger and more often had comorbid substance abuse or post-traumatic stress disorder compared to individuals with bipolar disorder who were not prescribed antipsychotic medication. Just over half (51.9%) of individuals appear to be fully adherent with antipsychotic medications, while 48.1% of individuals are either partially adherent or non-adherent with antipsychotic medications. Factors associated with treatment nonadherence were younger age, minority ethnicity, comorbid substance abuse and homelessness.Conclusions: Treatment non-adherence is a major issue for close to half of individuals with bipolar disorder prescribed antipsychotic medication. Additional studies are needed to better understand treatment adherence within the full range of pharmacologic therapies among individuals with bipolar disorder.

Psychotropic Medication Nonadherence Among United States Latinos: A Comprehensive Literature Review

“…Study objectives varied, with some focusing specifically on adherence (1, 6, 41, 44–47, 49, 51–60) while others measured adherence as part of studies addressing different questions. Geographically, eight were based in California (6, 42, 43, 47, 48, 50, 54, 55), two in Texas (41, 51), one in New Mexico (52), one in New York (49), one in Connecticut (56), one in Ohio (40), and four were from Veteran’s Administration National Registries (46, 58–60), and three were national studies (1, 45, 57). …”

“…Twelve reports (N= 12) investigated nonadherence to antipsychotics (1, 6, 41–43, 46, 49–51, 54, 58, 59), five antidepressants (45, 47, 52, 55, 57), two mood stabilizers (48, 60), and two a combination of these medications (40, 56). Ten studies focused on schizophrenia or schizoaffective disorder (1, 6, 41–43, 49–51, 59), five on depression (45, 47, 52, 55, 57), three on bipolar disorder (48, 58, 60), and three a combination of those diagnoses (40, 54, 56).…”

“…Because most studies examined only adherence and nonadherence, for studies that reported more adherence categories than adherent and nonadherent (6, 40, 58–60), we report all provided rates in Table 1, but for mean nonadherence rate calculations we used the summed partial adherence, nonadherence, and excess filler rates as the nonadherence rate. For the one paper (40) that reported separate adherence rates by ethnicity and diagnosis, we give the separate rates in Table 1, but for calculating mean nonadherence rates, we averaged the rates between diagnoses within each ethnic group.…”

“…have been shown to be generally more objective measures (3, 62). Therefore, we also separately analyzed the 11 papers (1, 6, 46, 48, 51, 52, 54, 56, 58–60) that used these typically more objective measures.…”

“…We did secondary calculations on study data for 11 studies (3 nonadherence percentage calculations (51, 55, 56), two chi-square tests (50, 57), and six both percentage calculations and chi-square tests (1, 40, 47, 49, 58, 60)). For the two studies (55, 56) in which the unadjusted and adjusted nonadherence rates yielded conflicting results, we included both findings, but used the results of the multivariate analysis when describing comparisons in rates between ethnic groups.…”