@article{ref1,
title="Changes in patient health questionnaire (PHQ-9) scores in adults with medical authorization for cannabis",
journal="BMC public health",
year="2020",
author="Round, Jessica M. and Lee, Cerina and Hanlon, John G. and Hyshka, Elaine and Dyck, Jason R. B. and Eurich, Dean T.",
volume="20",
number="1",
pages="e987-e987",
abstract="BACKGROUND: Legal access to medical cannabis is increasing world-wide. Despite this, there is a lack of evidence surrounding its efficacy on mental health outcomes, particularly, on depression. This study assesses the effect of medical cannabis on Patient Health Questionnaire (PHQ-9) scores in adult patients between 2014 and 2019 in Ontario and Alberta, Canada.   METHODS: An observational cohort study of medically authorized cannabis patients in Ontario and Alberta. Overall change in PHQ-9 scores from baseline to follow-up were evaluated (mean change) over a time period of up to 3.2 years.   RESULTS: 37,338 patients from the cohort had an initial PHQ-9 score recorded with 5103 (13.7%) patients having follow-up PHQ-9 scores. The average age was 54 yrs. (SD 15.7), 46% male, 50% noted depression at baseline. The average PHQ-9 score at baseline was 10.5 (SD 6.9), following a median follow-up time of 196 days (IQR: 77-451) the average final PHQ-9 score was 10.3 (SD 6.8) with a mean change of - 0.20 (95% CI: - 0.26, - 0.14, p-value < 0.0001). Overall, 4855 (95.1%) had no clinically significant change in their PHQ-9 score following medical cannabis use while 172 (3.4%) reported improvement and 76 (1.5%) reported worsening of their depression symptoms.   CONCLUSIONS: Although the majority showed no clinically important changes in PHQ-9 scores, a number of patients showed improvement or deteriorations in PHQ-9 scores. Future studies should focus on the parallel use of screening questionnaires to control for PHQ-9 sensitivity and to explore potential factors that may have attributed to the improvement in scores pre- and post- 3-6 month time period.<p /> <p>Language: en</p>",
language="en",
issn="1471-2458",
doi="10.1186/s12889-020-09089-3",
url="http://dx.doi.org/10.1186/s12889-020-09089-3"
}