Underlying heterogeneity among individuals with cocaine dependence is widely postulated in the literature; however, identification of a group of factors that explain risk of cocaine use severity has yet to be confirmed.
Latent mixture modeling evaluated 338 cocaine-dependent individuals recruited from the community to assess the evidence for the presence of distinct subgroups. Variables included 5 baseline questionnaires measuring cognitive function (Shipley), impulsivity (BIS), mood (BDI), affective lability (ALS), and addiction severity (ASI). Results failed to suggest multiple subgroups. Given a lack of evidence for discrete latent classes, an exploratory factor analysis followed by exploratory structural equation modeling was implemented to identify functional dimensions to enhance interpretation of these variables.
Findings from the exploratory factor analysis indicated a 3-factor model as the best fit, and the subsequent exploratory structural equation modeling solution resulted in associations with lifetime cocaine use. Factor 1, best characterized by demographic factors (sex and age), is associated with less lifetime cocaine use. Psychological problems best characterize factor 2, which is associated with higher lifetime cocaine use. Finally, factor 3 is characterized by other substance use (alcohol and marijuana). Although this factor did not demonstrate a statistically reliable relation with self-reported, lifetime cocaine use, it did indicate a potentially meaningful positive association.
These 3 factors delineate dimensions of functioning that likewise help characterize the variability found in previously established associations with self-reported cocaine use.
The University of Texas Health Science Center at Houston, Houston, TX
The authors declare no conflict of interest.
Reprints: Nadeeka R. Dias, BSc, The University of Texas Health Science Center at Houston, 1941 East Rd., Houston 77054, TX (e-mail: firstname.lastname@example.org).