Family Environment and Intergenerational Exposure on Drug Use Patterns among Patients with Substance Use Disorders in South-West Nigeria: A Structural Equation Modelling Approach

The study, a cross-sectional descriptive survey, examined how family environment and
exposure across generations affect current drug use among 425 adult drug users attending
treatment centers in Southwest Nigeria. Structural Equation Modelling (SEM) was used. Six
family-level factors were examined: cohesion, expressiveness, conflict, exposure to family
substance use, perceived impact, and preventive communication. The analysis is based on
Social Learning Theory and Family Systems Theory. The SEM showed a very good fit with
the data (SRMR = 0.013, d ULS = 0.0569, d G = 0.0388). The strongest predictor of current
drug use was exposure to family substance use (β = 0.4760, p < .001, f² = 0.1136), highlighting
the role of observational learning. Family cohesion had a significant negative direct effect (β =
–0.1707, p = .0396, f² = 0.0332), meaning it offered protection. Preventive communication
showed a negative effect that was marginal (β = –0.2299, p = .0813). Expressiveness produced
an unexpected positive indirect effect through exposure (β = 0.1108, p = .0086, VAF = 63.1%).
This suggests that expressiveness may become a risk factor when exposure is high. The
relationship between exposure and drug use was significantly mediated by perceived impact
(VAF = 57.1%, β = 0.3404, p < .001), pointing to the importance of emotional trauma. Family
conflict had no significant effect (β = –0.0338, p = .6029). Taken together, the results support
culturally tailored, family-based, and trauma-informed interventions in Nigeria. Structured
family therapy and attention to emotional trauma from family substance use could help prevent
relapses and improve treatment outcomes.