Rates of and Factors Associated with Psychotropic Medication Adherence In Latinos: A Systematic Review of the Literature

Authors: Nicole Lanouette, MD, David Folsom, MD, MPH, Andres Sciolla, MD, Dilip V. Jeste, MD

Background:
Although medications for schizophrenia, depression, and bipolar disorder improve health outcomes, psychotropic adherence averages only 40-65%. Ethnic disparities exist, but few adherence studies have focused on Latinos. We conducted this systematic literature review to establish reported rates of and factors influencing psychotropic medication adherence among United States Latinos.

Methods:
We searched the MEDLINE and PsycINFO databases and bibliographies from recent reviews and relevant articles for studies published since 1980 that reported rates of and/or factors associated with antipsychotic, antidepressant, or mood stabilizer adherence in United States Latino adults. In total, 21 studies met our inclusion criteria.

Results:
Total N of participants ranged from 30 – 44,637, and the proportion of Latino participants in the 16 studies including multiple ethnic groups was 2.9 – 56% (mean 18.5). In the 7 studies reporting Latino participants’ preferred language and country of origin, 40.8% (SD 32.9) preferred Spanish, and country of origin was most frequently Mexico (N=5). The mean adherence rate in studies including only Latinos was 52.7% (SD 10.9). In studies including Latinos and other ethnic groups, the rates were: 63.8% (SD 15.2) overall; 59.2% (SD 16.2) for Latinos, 68.8% (SD 17.1) for non-Latino whites; and 56.9% (SD 16.8) for African Americans. The majority of studies (N=10 of 15) found Latinos had statistically significantly lower adherence rates than non-Latino whites, while 5 found no significant differences. The identified influences on adherence - including factors that may be uniquely or especially relevant for Latinos, such as language, acculturation, and family support -are reviewed. Additionally, we identify knowledge gaps and provide research recommendations.

Conclusions:
United States Latinos receiving mental health treatment appear to be at increased risk for psychotropic medication nonadherence. Influences particularly relevant for Latinos have been identified; further clarifying their effect and which subpopulations are most at-risk are essential for optimizing future interventions.