Risk of Dependency
One of the touted potential benefits of the decriminalization of marijuana is that cannabis dependence is less harmful than alcohol dependence. Granted the percentage of persons using cannabis who become dependent is only about 9%, compared to approximately 15% who become dependent on alcohol. But do cannabis-dependent persons have less social and economic problems than those who are alcohol-dependent?
Only 45% of American adolescents rate cannabis as risky
Dunedin Study
A long-term longitudinal study on the health and behavior of 1,037 consecutive births between 1972 and 1973 has been ongoing in the city of Dunedin in New Zealand. This report is based on 947 participants (94% of the 1,007 study members who are still alive), and who have completed at least 3 out of 5 adult cannabis assessments from ages 18 to 38 years. The following graph shows the change in social class (top) with participants who never used cannabis; used but had no diagnosis of cannabis dependence; and with 1, 2 and 3+ diagnosis of cannabis dependence. With increasing cannabis dependence there was increasing decline in social class from childhood to age 38 years.
The bottom graph shows a similar increase in financial difficulties at age 38 years with increasing cannabis dependency.
Conclusion
The authors concluded that:Cannabis dependence was more strongly linked to financial difficulties than was alcohol dependence; it was not associated with less downward mobility, antisocial behavior in the workplace and relationship conflict than was alcohol dependence. This finding stands in contrast to the popular and expert opinion which states that heavy alcohol use imposes more economic and social costs than does heavy cannabis use.
Cerdal, M., Moffitt, T.E., Meier, M.H., Harrington, H., Houts, R., Ramrakha, S., Hogan, S., Poulton, R., and Caspi, A., “Persistent Cannabis Dependence and Alcohol Dependence Represent Risks for Midlife Economic and Social Problems: A Longitudinal Cohort Study”, Clinical Psychological Science, 1-19, 2016