The familial aggregation of cannabis use disorders.
OBJECTIVE
The aim of this paper is to examine the familial aggregation of cannabis use disorders and other psychiatric conditions among first-degree relatives and spouses of probands with a cannabis use disorder.


METHODS
Controlled family study methods.


METHODS
Out-patient psychiatric clinics and the local community (same geographic area).


METHODS
Two hundred and sixty-two probands with a life-time history of cannabis use disorder, alcohol dependence, anxiety disorders or no history of any disorder, and their first-degree relatives and spouses.


METHODS
Cannabis use disorders and other DSM-III-R disorders in the relatives and spouses using the Schedule for Affective Disorders and Schizophrenia.


RESULTS
Results reveal an elevated risk of life-time history of cannabis use disorders among siblings [odds ratio (OR: 3.6), adult offspring (OR): 6.9], and spouses (OR: 4.4) of probands with cannabis use disorders. There is a latent familial factor underlying cannabis use disorders that was shared partially with alcohol abuse/dependence. Comorbid mood and anxiety disorders aggregated independently from cannabis use disorders in families. Equal elevation in the magnitude of the association among the first-degree adult relatives and spouses of probands with a cannabis use disorder suggests the probable contribution of both environmental and genetic factors.


CONCLUSIONS
These findings support a family-based approach to drug abuse intervention and the importance of future research concerning environmental mediators of familial transmission of drug abuse.
Merikangas
Kathleen R
KR
Section on Developmental Genetic Epidemiology, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20814-3720, USA. kathleen.merikangas@nih.gov
Li
Julan Julia
JJ
Stipelman
Brooke
B
Yu
Kelly
K
Fucito
Lisa
L
Swendsen
Joel
J
Zhang
Heping
H