Efficacy indicators of four methods in outpatient addiction treatment

Abstract Background In Portugal, as far as we know, there are no recent studies that evaluated the comparative efficacy of therapeutic modalities in addiction problems by reference to a holistic and psychosocial model of effectiveness. Objectives Using a sample of Portuguese patients in outpatient treatment for drug and alcohol abuse, this study aimed to examine if a combined treatment modality (group therapy with individual intervention) had greater overall efficacy when compared to other three types of treatment without group therapy. Methods This is a correlational and cross-sectional study using a convenience sample of patients (N = 254) from an outpatient treatment in the Intervention Service on Addictive Behaviors and Substance Dependence. At the time of data collection, the patients were attending four types of treatment, such as receiving intervention based on individual psychological counseling (n = 66); receiving individual psychiatric counseling (n = 68); receiving both individual psychological and psychiatric counseling (n = 102); and receiving not only individual counseling (i.e., psychology or psychiatry), but also attending group therapy (n = 18). Results Using MANOVA and Wilks’s multivariate test criterion, there was a significant effect of treatment modality on the global efficacy, Λ = 0.88, F(9, 603) = 3.75, p