BACKGROUND: Knowledge regarding the causes of comorbidity among substance use disorders can have significant impact on future research examining the etiology of these disorders. Unfortunately, the conclusions of past studies examining the comorbidity among substance use disorders are conflicting; some studies emphasize familial influences common to multiple substances, while others emphasize substance-specific influences. Discrepancies in results may reflect different analytical approaches or differences in the samples. Here, we examine the causes of comorbidity between alcohol dependence and illicit drug dependence in adolescents. METHODS: We ascertained a clinical sample of adolescents treated for antisocial behavior and substance use disorders and their siblings and a matched control sample. A model fitting approach was used to test 13 alternative hypotheses for the causes of comorbidity. RESULTS: The best supported hypothesis for the comorbidity between alcohol dependence and illicit drug dependence was a model hypothesizing that comorbid disorders are alternate forms of a single underlying liability. The next best fitting models were two of the correlated liabilities models (correlated risk factors and reciprocal causation). DISCUSSION: The results suggest that the best hypotheses explaining the comorbidity between alcohol and illicit drug dependence in adolescents are that alcohol dependence and illicit drug dependence are manifestations of a single general liability to develop substance dependence or that there are separate liabilities that are highly correlated.
BACKGROUND: Knowledge regarding the causes of comorbidity among substance use disorders can have significant impact on future research examining the etiology of these disorders. Unfortunately, the conclusions of past studies examining the comorbidity among substance use disorders are conflicting; some studies emphasize familial influences common to multiple substances, while others emphasize substance-specific influences. Discrepancies in results may reflect different analytical approaches or differences in the samples. Here, we examine the causes of comorbidity between alcohol dependence and illicit drug dependence in adolescents. METHODS: We ascertained a clinical sample of adolescents treated for antisocial behavior and substance use disorders and their siblings and a matched control sample. A model fitting approach was used to test 13 alternative hypotheses for the causes of comorbidity. RESULTS: The best supported hypothesis for the comorbidity between alcohol dependence and illicit drug dependence was a model hypothesizing that comorbid disorders are alternate forms of a single underlying liability. The next best fitting models were two of the correlated liabilities models (correlated risk factors and reciprocal causation). DISCUSSION: The results suggest that the best hypotheses explaining the comorbidity between alcohol and illicit drug dependence in adolescents are that alcohol dependence and illicit drug dependence are manifestations of a single general liability to develop substance dependence or that there are separate liabilities that are highly correlated.
Authors: Rohan H C Palmer; Tanya M Button; Soo H Rhee; Robin P Corley; Susan E Young; Michael C Stallings; Christian J Hopfer; John K Hewitt Journal: Drug Alcohol Depend Date: 2012-01-11 Impact factor: 4.492
Authors: Rohan H C Palmer; Leslie Brick; Nicole R Nugent; L Cinnamon Bidwell; John E McGeary; Valerie S Knopik; Matthew C Keller Journal: Addiction Date: 2015-01-20 Impact factor: 6.526
Authors: J D Grant; M T Lynskey; P A F Madden; E C Nelson; L R Few; K K Bucholz; D J Statham; N G Martin; A C Heath; A Agrawal Journal: Psychol Med Date: 2015-08-18 Impact factor: 7.723
Authors: Arpana Agrawal; Julia D Grant; Andrew Littlefield; Mary Waldron; Michele L Pergadia; Michael T Lynskey; Pamela A F Madden; Alexandre Todorov; Timothy Trull; Kathleen K Bucholz; Richard D Todd; Kenneth Sher; Andrew C Heath Journal: J Stud Alcohol Drugs Date: 2009-03 Impact factor: 2.582