This study evaluated an hypothesized model of biopsychosocial factors that mediate the relationship between childhood abuse and substance abuse. A questionnaire packet consisting of self-report measures was administered to 160 drug dependent participants with and without co-occurring psychological disorders in residential, partial, and outpatient treatment at the Diagnostic Rehabilitation Center in Philadelphia, Pennsylvania. Self-report measures assessed biopsychosocial factors consisting of familial alcoholism and mental illness, childhood abuse, self-esteem, family and social support, belief systems, mood states, coping methods, risk behaviors, and substance use. A path analysis was conducted to assess the theoretical model, and to explore the direct and indirect relationships among childhood abuse, biopsychosocial factors, and substance use. The results partially support the hypothesis that child abuse is indirectly related to substance use through mediating factors of negative family and social support, low esteem, avoidance coping, avoidance and affective beliefs, and health and risk behaviors. In addition, exploratory path analyses demonstrated sexual abuse and emotional neglect are directly related to alcohol and other drug use among women in residential treatment. These findings support the hypothesized paradigm in understanding the nature of substance use as an avoidance coping method for biopsychosocial factors promoted by childhood abuse. Appendixes include items such as demographics; childhood trauma questionnaire; mood scale; substance beliefs; substance use survey; and gender and treatment survey results. (Contains 157 references.) (Author/JDM)