The CADD (Center on Antisocial Drug Dependence) began in 1988 with a feasibility project entitled “Teenage substance abusers and their families”. The following year, a pilot project was funded by NIDA. The original participants were 25 adolescent boys (ages 14-18) who had entered a residential treatment program at the CU Health Sciences Center and 25 control boys (a control subject is someone who is the same age, has a similar family structure and lives in the same area). The family members of these first 50 subjects were also included in the study.

In 1992, the project was renewed with funding from NIDA and expanded to include an additional 242 male and female individuals in treatment and 200 control participants, as well as 1450 family members (including parents, siblings, and some extended family members). At this time, families in the CAP (Colorado adoption project) were also included in the study. All study participants were given confidential interviews related to mental health and substance use behaviors.

The project was renewed in 1997 and DNA was also collected from willing participants. Additionally, Longitudinal Twin Study and Community Twin Study participants and their families were enrolled. By 2003, data had been collected on nearly 5000 individuals. At this time, a follow up study was proposed to look at how individuals in the study had changed over time. Follow-up interviews were then conducted with subjects over the next 5 years (2003-2008).

In 2008, the center shifted direction to include a focus on risk behaviors related to HIV/AIDS. Substance use is one factor associated with this risk, as are other factors collectively referred to as behavioral inhibition. Currently, a third round of interviews is being conducted with participants. This longitudinal data will include measures of additional risk taking behavior, as well as recurring questions about substance use and mental health.

As it enters its third decade, the CADD remains a highly unique longitudinal study which includes the largest sample in existence combining individuals in treatment and their families, together with a twins study, a control family study and an adoption study. Nearly 100 scientific papers have been written using data from this project, and much has been learned about the genetics of substance abuse, antisocial behaviors, and risk taking behaviors. New data collection and analysis will help increase our understanding about factors that lead to drug abuse and HIV related risk behavior. This knowledge, in turn, will contribute to the development of strategies aimed at reducing the risk of drug abuse and addiction, STDs and HIV/AIDS.