The National Survey on Drug Use and Health (NSDUH, 2008) reported that among illicit drug users, 15.2 million report using marijuana, 75.6% reported using marijuana in the past month, and 53.3% reported using marijuana exclusively. Public concerns over marijuana use have decreased over the past few years. Consequently, daily adolescent marijuana use is on the rise, reaching 1.2% of 8th graders, 3.3% of 10th graders, and 6.1% of 12th graders according to Monitoring the Future Survey (2010).
A recent study (Large et al., 2011) found marijuana use precipitates schizophrenia and other psychotic disorders in some individuals. Specifically, the age of onset of psychosis increased by 2.75 years for marijuana users compared to non-users. This finding confirms an association between marijuana use and the mean age of early onset of psychotic illness, and supports the causal role of marijuana in the development of psychosis for some individuals. Adolescents using marijuana with a family history of psychotic disorders are particularly at risk of early onset of psychotic illness.
Early onset of schizophrenia and other psychotic disorders is extremely problematic, because individuals who develop these conditions at younger ages are much less likely to attain important developmental milestones, such as high school graduation, gainful employment, meaningful relationships, etc. In contrast, later onset of these disorders may allow individuals time to progress further toward developmental goals, decreasing the overall impact on the person’s life as well as treatment costs.
Consequently, delaying the onset of schizophrenia as well as other psychotic disorders by decreasing adolescent marijuana use appears to be a worthwhile endeavor. Talking to at-risk youth about the causal role of marijuana use and the development of psychosis, role modeling, and supporting a lifestyle without marijuana may help to reduce pot use among teens. Seeking out an expert in this area to validate these concerns and provide further education to at-risk youth—particularly those with a family history of psychotic disorders—can also help. Lastly, it is important to help at-risk youth find a social group that discourages, rather than promotes, marijuana use.
Working together, we can do much to reduce the pain and suffering of early onset schizophrenia and other psychotic disorders, improve quality of life for these individuals, and reduce the overall costs of these illnesses on families, communities, and health care systems.