Examining the stepping-off hypothesis among young adult marijuana users in Los Angeles

Background:

The “stepping-off hypothesis,” in contrast to the conventional “gateway hypothesis,” suggests that marijuana use might be associated with reduced or lower illicit drug use in some cases. We evaluated the stepping-off hypothesis among a sample of marijuana users (aged 18-26 years) by examining whether patient status (medical marijuana patients (MMP) vs. non-patient marijuana users (NPU) and self-reported medical purpose of marijuana use (for medical reasons at least on half occasions in the past 90 days) predicted 90-day illicit drug use.

Methods:

187 MMP and 114 NPU were recruited in Los Angeles during 2014-15. Study participants were surveyed about reasons for and rates of marijuana use, illicit drug use, and health outcomes. Logistic regression analysis investigated effects of patient status, marijuana use for medical purposes, and other covariates on 90-day illicit drug use.

Results:

61% of the sample were MMP, and 59% reported using marijuana for medical purposes at least on half or more occasions in the past 90 days. 75% reported lifetime and 31% reported 90-day illicit drug use, such as cocaine, MDMA and mushrooms.  No differences in 90-day illicit drug use were found between MMP and NPU.  However, participants who reported using marijuana for medical purposes on half or more occasions were significantly less likely to use illicit drugs (OR=0.58, P<0.05), more likely to use marijuana with higher frequency (175 vs 118 days in the past 90 days, P<0.001), and scored higher on anxiety (P<0.05) and somatization (P<0.01) subscales.

Conclusion:

In this sample of marijuana-using young adults, results provide preliminary support for the stepping-off hypothesis: marijuana use for medical purposes (but not medical marijuana patient status) was associated with lower rates of illicit drug use.