Cognitive Behavioral Treatment and Substance Abusing Minority Adults: A Meta-Analysis

Background and Purpose:  Research has shown that CBT is an effective intervention for reducing substance abuse (Morgenstern et al., 2007). However, scholars have cautioned against the generalization of these findings to minority populations, since CBT clinical trials have typically included mostly White samples (Suinn, 2003). Thus, we conducted a meta-analysis to compare CBT’s effectiveness in reducing substance abuse between Black/Latino and White participants.

Method: Article selection followed the recommendations of Johnson and Eagly (2000), which included: 1) Searching scientific databases; 2) searching for unpublished work; and 3) using reference lists to find additional articles. The search yielded 281 articles that were subsequently reviewed by three raters using the following inclusion criteria: 1) Studies conducted in the United States; 2) studies published or conducted between 1990 and 2010; 3) studies with samples 18 years of age and over; 4) studies using an experimental design; and 5) studies including at least one substance abuse outcome.  SPSS was used to process studies’ demographic variables, methodology, and findings.  Effect size analysis was conducted using Comprehensive Meta-Analysis software. To compute individual effect sizes from each study, we compared: 1) The experimental group and control groups for each substance abuse outcome at each follow-up point; 2) pre and posttest differences for each substance abuse outcome at each follow up point for the CBT group.  An aggregate effect size was calculated from the mean of the Hedges’ g effect size estimates in order to reduce artificial inflation/ deflation. To assess and compare CBT’s effectiveness between White and Black/Latino samples, studies were divided into two subgroups: Studies with a predominantly White sample and studies with a predominantly Black/ Latino sample. Effect size was weighted by the inverse of its variance and confidence intervals were calculated. Then we computed I² and Q statistics. 

Results: The analysis included 19 studies comprising a total of 176 effect sizes and N = 4,175 individuals. CBT and comparison group therapies had similar effects on substance abuse across racial groups in the posttest group comparison. Pre/ posttest comparisons indicated CBT’s impact was half as strong for studies with a predominantly Black/Latino sample (g =.43; 95% CI: .52 - .68; p = .001; I² = 35.51) compared to studies with a predominantly White sample (g = 1.00; 95% CI: .68 – 1.32; p = .000; I² = 91.35). Random effects meta-regression analysis failed to identify significant effects with respect to race, treatment format, type of substance, sample size, number of CBT sessions, and use of intent to treat analysis on effect size. Treatment retention was lower for studies with a predominantly Black/Latino sample when compared to their White counterparts. 

Conclusions and Implications: Results indicated that CBT is an effective treatment for reducing substance abuse among both White and Black/Latino adults. However, results revealed that CBT and comparison treatments may be less effective for Black/Latino populations than White populations. Results highlight the need for further research examining the impact of evidence-based treatments, such as CBT, on substance abuse among Blacks and Latinos.