Factors associated with antidepressant adherence for Medicaid-enrolled children and adolescents

Antidepressants have been shown to be efficacious for the treatment of pediatric depression. However, many youths do not receive an adequate duration of treatment, and factors associated with nonadherence in this population remain poorly understood.

To examine rates of antidepressant adherence for depressed youth and identify factors associated with adherence during the acute and continuation phases of treatment.

A retrospective cohort analysis was conducted using claims data from a state Medicaid-enrolled population of 1650 youths (aged 5-17 years) with new episodes of depression between January 1, 2005, and December 30, 2007. These patients were treated with selective serotonin reuptake inhibitors or newer antidepressants and followed for 6 months from the first prescription fill date. Adherence measures were derived from the Health Plan Employer Data and Information Set (HEDIS) quality indicators on antidepressant management (3 months of continuous treatment for the acute phase and 6 months for the continuation phase) and assessed using the medication possession ratio. Multivariate logistic regression analyses evaluated the association between demographic, clinical, medication, and treatment factors, and adherence.

About half (49.5%) of the youths were adherent to antidepressant medication during the acute phase, and 42% of these were adherent during the continuation phase; 21% were adherent across both treatment phases. Optimal follow-up visits and adequate antidepressant dosing was associated with better adherence during both treatment phases, as was use of other psychotropic medications. Youths prescribed trazodone for sleep had higher adherence rates during the acute phase. Minority youths and adolescents had lower adherence rates during the acute phase. Youths in foster care had higher adherence rates during both treatment phases.

Nonadherence with antidepressant medications is common among Medicaid-covered children and adolescents. Study findings underscore the need for clinicians to deliver guideline-concordant care, assess adherence, and develop interventions that improve adherence, particularly for vulnerable subgroups.