Table 2.
Peer-reviewed longitudinal analyses of the association between medical marijuana laws and various outcomes
| Outcome variable | Source | Association with medical marijuana |
|---|---|---|
| Marijuana prevalence among youth | Khatapoush & Hallfors (2004) | Not statistically significant |
| Harper et al. (2012) | Negative, but statistical significance depends on specification | |
| Wall et al. (2012) | Not statistically significant once Montana or Vermont is dropped | |
| Lynne-Landsman et al. (2013) | Not statistically significant | |
| Schuermeyer et al. (2014) | Not statistically significant for commercialization on prevalence; marginally significant positive effect on abuse/dependence | |
| Choo et al. (2014) | Not statistically significant | |
| Anderson et al. (2015) | Not statistically significant | |
| Wen et al. (2015) | Positive for initiation for those 12–20; positive for dispensaries and past-month use | |
| Pacula et al. (2015) | Not statistically significant for dispensaries, mixed for other aspects of MML | |
| Hasin et al. (2015); Keyes et al. (2016) | Negative for eighth-graders; no statistically significant effect for other grades | |
| Martins et al. (2016) | Not statistically significant | |
| Stolzenberg et al. (2016) | Positive | |
| Wall et al. (2016) | Not statistically significant | |
| Johnson et al. (2017) | Not statistically significant for MML, but positive with higher possession limits and a voluntary registration | |
| Marijuana prevalence among adults | Gorman & Huber (2007) | Not statistically significant |
| Harper et al. (2012) | Not statistically significant | |
| Schuermeyer et al. (2014) | Not statistically significant | |
| Pacula et al. (2015) | Positive association with dispensaries (all ages; no test for adults only) | |
| Wen et al. (2015) | Positive for adults 21+ | |
| Martins et al. (2016) | Positive for adults 26+ | |
| Alcohol use | Anderson et al. (2013) | Negative for adults |
| Sabia et al. (2015) | Negative for binge drinking for adults | |
| Wen et al. (2015) | Not statistically significant for those 12–20; positive for frequency of binge drinking among those ages 21+ | |
| Opioids | Bachhuber et al. (2014) | Negative for overdose deaths |
| Wen et al. (2015) | Not statistically significant for prescription painkiller misuse | |
| Bradford & Bradford (2016) | Negative for pain medication prescriptions in Medicare D population | |
| Kim et al. (2016) | No statistically significant effect for drivers in fatal crashes testing positive for opioids; negative for those aged 21–40 | |
| Bradford & Bradford (2017) | Negative for pain medication prescriptions among Medicaid enrollees | |
| Suicide rates | Anderson et al. (2014) | Negative |
| Rylander et al. (2014) | Negative | |
| Grucza et al. (2015) | Not statistically significant |
Abbreviation: MML, medical marijuana law (dichotomously coded).