This exploratory study aims to investigate whether anxiety, depression, and pain are associated with changes in marijuana use and drug use consequences among primary care patients.
In all, 331 adult primary care patients with marijuana as the only drug used were followed prospectively to investigate associations between anxiety/depression symptoms (no/minimal symptoms; anxiety or depression symptoms; symptoms of both) and pain (1-10 scale: none [0]; low [1-3]; medium [4-6]; high [7-10]) (independent variables) and substance use outcomes in regression models. These outcomes were changes (over 6 months) in primary outcomes: marijuana use days (past 30); and drug use consequences (Short Inventory of Problems-Drugs [SIP-D]); secondary outcomes-drug use risk (Alcohol, Smoking, and Substance Involvement Screening Test [ASSIST] score for drugs).
At baseline, 67% reported no/minimal anxiety/depression symptoms, 16% anxiety or depression symptoms, 17% both; 14% reported no pain, 16% low, 23% medium, 47% high pain level. Mean (SD) number of marijuana use days was 16.4 (11.6), mean SIP-D 5.9 (9.0), mean ASSIST 12.5 (7.8); no significant association was found between anxiety/depression and marijuana use changes. Given the same baseline status for SIP-D and ASSIST, respectively, those with anxiety or depression had greater increases in SIP-D (adjusted mean difference [95% confidence interval] +3.26 [1.20; 5.32], P = 0.004) and borderline significant increases in ASSIST (+3.27 [-0.12; 6.65], P = 0.06) compared with those without anxiety or depression; those with both anxiety and depression had greater increases in ASSIST (+5.42 [2.05; 8.79], P = 0.003), but not SIP-D (+1.80 [-0.46; 4.06], P = 0.12). There was no significant association between pain and marijuana use and SIP-D changes. Given the same baseline ASSIST level, those with high pain level had greater increases in ASSIST (+4.89 [1.05; 8.72], P = 0.04) compared with those with no pain.
In these exploratory analyses, anxiety, depression, and high pain level appear to be associated with increases in drug-related harm among primary care patients using marijuana.