The association between substance use disorders and early and combined use of alcohol and marijuana in two American Indian populations

Abstract

Objective: To study the relationships between early and combined use of alcohol and marijuana with diagnoses of alcohol and marijuana use disorders in two American Indian (AI) populations.

Method: Data were drawn from a psychiatric epidemiologic study of 3084 AIs living on or near two reservations. We analysed data for adults aged 18–54 years at the time of interview (n = 2739). Logistic regression models were estimated to examine associations between early and combined use of alcohol and marijuana with lifetime diagnoses of abuse and dependence.

Results: Overall, younger AIs (18–29 years old) were more likely than older AIs (40–54 years old) to initiate substance use early and initiate use with marijuana, with or without alcohol. Persons who initiated alcohol use before age 14 were more than twice as likely as those who initiated use at older ages to meet criteria for alcohol or marijuana use disorders (p < 0.01). The odds of abuse or dependence were two to five times higher among persons who reported combined use of alcohol and marijuana (p< 0.01) than among those who reported use of either substance.

Conclusions: These findings document the need to address both early and combined use of alcohol and marijuana in prevention and treatment programmes.

• American Indians
• alcohol
• marijuana

Acknowledgements

AI-SUPERPFP would not have been possible without the significant contributions of many people. The following interviewers, computer/data management and administrative staff supplied energy and enthusiasm for an often difficult job: Anna Barón, Antonita Begay, Amelia Begay, Cathy Bell, Phyllis Brewer, Nelson Chee, Mary Cook, Helen Curley, Mary Davenport, Rhonda Dick, Pearl Dull Knife, Geneva Emhoolah, Roslyn Green, Billie Greene, Fay Flame, Jack Herman, Tamara Holmes, Shelly Hubing, Cameron Joe, Louise Joe, Cheryl Martin, Jeff Miller, Robert Moran, Natalie Murphy, Melissa Nixon, Ralph Roanhorse, Margo Schwab, Jennifer Settlemire, Donna Shangreaux, Matilda Shorty, Selena Simmons, Wileen Smith, Tina Standing Soldier, Jennifer Truel, Lori Trullinger, Arnold Tsinajinnie, Marvine Two Eagle, Jennifer Warren, Intriga Wounded Head, Dawn Wright, Jenny Yazzie and Sheila Young. We also acknowledge the contributions of the Methods Advisory Group: Margarita Alegria, Evelyn Bromet, Peter Guarnaccia, Steve Heeringa, Ron Kessler, R. Jay Turner and William Vega. Finally, we thank the tribal members who so generously answered all the questions asked of them. Relevant ethical safeguards have been met in relation to the confidentiality and consent of the tribal members involved in the research. The university and the tribal institutional review boards approved the study protocol.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.