Problem Solving Therapy for Depressed Older Adult Methadone Clients: A Randomized Controlled Trial

Background and Purpose

The population of adults receiving treatment for opioid abuse is aging. Understanding the interconnectedness of psychiatric and substance abuse disorders is critical to providing appropriate services to an aging population. This study compared the efficacy of Problem Solving Therapy (PST) and Treatment as Usual (TAU) in decreasing rates of depressive symptoms for older adults over the age of 50 in methadone maintenance treatment. PST is designed to teach problem solving skills and is often used by social workers. Since PST is an empirically-tested relatively brief intervention for older adults with late-life mood disorders, it was hypothesized that PST participants would have decreased depression over time.

Methods

Participants were at least 50 years old, attended a methadone clinic from three to seven days a week, and had a depression score of 10 or greater as measured by the PHQ-9. The PHQ-9 is a 9-item scale used to identify a depressive disorder or to summarize the severity of depressive symptoms. The nine items reflect the criteria for depression provided in the DSM-IV. The PHQ-9 has demonstrated reliability, validity, and good measures of sensitivity and specificity with a variety of different clinical populations. It has demonstrated internal consistency and convergent validity with outpatient substance abusers and has identified mild depression in residential substance abuse clients. 

Forty-seven participants were randomly assigned to the PST or TAU group. Participant assessments at baseline, and one-month, 3-months, and 6-months after the acute treatment period were analyzed. A series of t-tests and chi-square tests were conducted to test the randomization to treatment group. Custom pairwise tests and a mixed analysis of variance were performed on the analytic group on their depression scores as a function of time and randomized group assignment. 

Results

A test of the a priori hypothesis was conducted using Bonferroni adjusted alpha levels of .00625 per test (.05/8). Results indicated that the pattern of difference on depression scores was significantly different at the 6-months durability phase (M=7.625, SE=1.056) compared to baseline (M=11.313, SE=.681) for the PST group. There was an overall significant main effect of time on depression scores. 

Conclusions and Implications

The findings suggest that over time, participants in PST successfully lowered their depression score. Given the results over time for the PST group, it suggests that methadone maintenance programs may successfully implement other potentially effective treatments. Social workers who utilize interventions, such as PST, can engage integrated treatment models for substance abuse related disorders that account for age-related physiological, cognitive, and social changes due to old age.