Childhood sexual abuse and risks for licit and illicit drug-related outcomes: a twin study.
BACKGROUND
This study examined the relationships between self-reported childhood sexual abuse (CSA) and drug-related outcomes in an Australian twin panel.


METHODS
A semi-structured psychiatric interview was conducted in 1996-2000 by telephone with young adult Australian twins (mean age 29.9 years). Data reported here are from 6050 twins who responded to both CSA and drug-related items.


RESULTS
A history of CSA was associated with significant risk for subsequently occurring regular smoking and use of each illicit drug class. Further CSA-associated risk was found among regular users, for nicotine and alcohol dependence, and among illicit drug users, for abuse/dependence of most drug classes. In same-sex discordant pairs, significant risk for regular smoking and illicit drug use was found in twins with a history of CSA compared to their non-abused co-twins. Similar analyses for abuse/dependence found significant risk for opioids, any illicit drug, and any non-cannabis illicit drug. CSA was associated with significantly earlier drug use. Despite the association of CSA with risk for early-onset cannabis use and regular smoking, risks for illicit drug outcomes associated with CSA and with either form of early-onset use combine in near-additive fashion.


CONCLUSIONS
CSA is associated with risk for subsequently occurring regular smoking and illicit drug use and abuse/dependence. Risks for drug use are mildly attenuated with control for familial contributions; similar risks for abuse/dependence remain significant for opioids and for illicit drugs combined across classes. Although we found evidence of earlier onset drug use with CSA, risks associated with CSA and with early-onset use combine in a largely additive manner.
Nelson
Elliot C
EC
Washington University School of Medicine, Department of Psychiatry, St Louis, MO 63110, USA. nelsone@wustl.edu
Heath
Andrew C
AC
Lynskey
Michael T
MT
Bucholz
Kathleen K
KK
Madden
Pamela A F
PA
Statham
Dixie J
DJ
Martin
Nicholas G
NG
D000328:Adult; D001315:Australia / Q000453:epidemiology; D002648:Child; D002650:Child Abuse, Sexual / Q000523:psychology* / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D013287:Illicit Drugs; D015994:Incidence; D008297:Male; D015995:Prevalence; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D019966:Substance-Related Disorders / Q000453:epidemiology*; D011795:Surveys and Questionnaires; D014427:Twins
D013287:Illicit Drugs