Drug use and dependence in cocaine dependent subjects, community-based individuals, and their siblings

Abstract

Background-The purpose of this study was to examine substance use and dependence among cocaine dependent subjects and their siblings compared to individuals recruited from the same neighborhood and their siblings in order to better understand family and neighborhood contributions to the development of dependence.Methods-Cocaine dependent subjects were recruited through treatment centers. Communitybased subjects were matched to cocaine dependent index cases on age, ethnicity, gender, and zip code. One full sibling for each case and community-based subject participated.Results-Cocaine dependent subjects were significantly more likely than community-based subjects to use all substances studied and were 2 to 10 times more likely to be dependent on alcohol and other illicit drugs. Dependence only on cocaine was uncommon (<10%). The siblings of cocaine dependent subjects had higher rates of substance use and were 1.3 to 3 times more likely to have a diagnosis of substance dependence compared siblings of community-based subjects. However, when analyses focused only on those who ever used a specific substance, the siblings of cocaine dependent cases were at a similar or modestly elevated risk (1.5 times) of developing dependence.Conclusions-Cocaine dependence is characterized by polysubstance use and dependence. In addition, the prevalence of substance dependence in the community subjects was higher than reported for the general population, indicating that cocaine dependent cases live in high-risk communities with elevated prevalence of substance dependence. A potential intervention to decrease the family clustering of dependence is to reduce the initiation of drug use in at risk relatives.

A genome-wide association study of alcohol dependence

“…Cocaine-dependent subjects were recruited systematically from chemical dependency treatment units in the greater St. Louis, MO, metropolitan area (35). Community-based comparison subjects were identified through the Missouri Family Registry and matched by age, race, gender, and residential zip code.…”

PKNOX2 gene is significantly associated with substance dependence in European-origin women

“…Cases and controls were selected from three large, complementary cohorts: Collaborative Study on the Genetics of Alcoholism (COGA), Family Study of Cocaine Dependence (FSCD), and Collaborative Genetic Study of Nicotine Dependence (COGEND). These three studies have been previously described (8,29,32,33). Lifetime dependence on nicotine, alcohol, marijuana, cocaine, opiates, or other dependence on other drugs was diagnosed in accordance with the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV).…”

Association of Gamma-Aminobutyric Acid A Receptor α2 Gene (GABRA2) with Alcohol Use Disorder

“…SAGE samples were genotyped on the Illumina Human1M array, including individuals from the Collaborative Study on the Genetics of Alcoholism (Edenberg, 2002), the Family Study of Cocaine Dependence (Bierut et al, 2008), and the Collaborative Genetic Study of Nicotine Dependence (Bierut, 2007). More details regarding the sample and quality control can be found at the dbGap (http:// www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?study_ id=phs000092.v1.p1).…”