Department of Psychology (Gravely, Driezen, Fong), University of Waterloo, Waterloo, Ont.; Hollings Cancer Center (McClure), Medical University of South Carolina, Charleston, SC; Roswell Park Comprehensive Cancer Center (Smith), Buffalo, NY; Ontario Institute for Cancer Research (Fong), Toronto, Ont.
CMAJ Open. 2023 Jun 13;11(3):E516-E526. doi: 10.9778/cmajo.20220081. Print 2023 May-Jun.
Tobacco smoking and cannabis use are independently associated with depression, and evidence suggests that people who use both tobacco and cannabis (co-consumers) are more likely to report mental health problems, greater nicotine dependence and alcohol misuse than those who use either product exclusively. We examined prevalence of cannabis use and depressive symptoms among Canadian adults who smoke cigarettes and tested whether co-consumers of cannabis and tobacco were more likely to report depressive symptoms than cigarette-only smokers; we also tested whether cigarette-only smokers and co-consumers differed on cigarette dependence measures, motivation to quit smoking and risky alcohol use by the presence or absence of depressive symptoms.
We analyzed cross-sectional data from adult (age ≥ 18 yr) current (≥ monthly) cigarette smokers from the Canadian arm of the 2020 International Tobacco Control Policy Evaluation Project Four Country Smoking and Vaping Survey. Canadian respondents were recruited from Leger's online probability panel across all 10 provinces. We estimated weighted percentages for depressive symptoms and cannabis use among all respondents and tested whether co-consumers (≥ monthly use of cannabis and cigarettes) were more likely to report depressive symptoms than cigarette-only smokers. Weighted multivariable regression models were used to identify differences between co-consumers and cigarette-only smokers with and without depressive symptoms.
A total of 2843 current smokers were included in the study. The prevalence of past-year, past-30-day and daily cannabis use was 44.0%, 33.2% and 16.1%, respectively (30.4% reported using cannabis at least monthly). Among all respondents, 30.0% screened positive for depressive symptoms, with co-consumers being more likely to report depressive symptoms (36.5%) than those who did not report current cannabis use (27.4%, < 0.001). Depressive symptoms were associated with planning to quit smoking ( = 0.01), having made multiple attempts to quit smoking ( < 0.001), the perception of being very addicted to cigarettes ( < 0.001) and strong urges to smoke ( = 0.001), whereas cannabis use was not (all ≥ 0.05). Cannabis use was associated with high-risk alcohol consumption ( < 0.001), whereas depressive symptoms were not ( = 0.1).
Co-consumers were more likely to report depressive symptoms and high-risk alcohol consumption; however, only depression, and not cannabis use, was associated with greater motivation to quit smoking and greater perceived dependence on cigarettes. A deeper understanding of how cannabis, alcohol use and depression interact among people who smoke cigarettes is needed, as well as how these factors affect cessation activity over time.
吸烟和使用大麻与抑郁症独立相关，有证据表明，同时使用烟草和大麻的人（共同使用者）比只使用其中一种产品的人更有可能报告心理健康问题、尼古丁依赖程度更高和酒精滥用。我们研究了加拿大成年吸烟者中大麻使用和抑郁症状的流行情况，并检验了大麻和烟草的共同使用者是否比只吸烟的人更有可能报告抑郁症状；我们还测试了只吸烟的人和共同使用者在吸烟依赖程度、戒烟动机和是否存在抑郁症状时的危险饮酒行为上是否存在差异。
我们分析了来自加拿大 2020 年国际烟草控制政策评估项目四国吸烟和电子烟调查的成年（年龄≥18 岁）当前（每月≥一次）吸烟者的横断面数据。加拿大的受访者是从莱杰的在线概率小组在所有 10 个省份招募的。我们估计了所有受访者中抑郁症状和大麻使用的加权百分比，并检验了大麻和烟草的共同使用者（每月至少使用一次大麻和香烟）是否比只吸烟的人更有可能报告抑郁症状。使用加权多变量回归模型来确定有和没有抑郁症状的共同使用者和只吸烟的人之间的差异。
共有 2843 名当前吸烟者参与了研究。过去一年、过去 30 天和每天使用大麻的比例分别为 44.0%、33.2%和 16.1%（30.4%报告至少每月使用一次大麻）。在所有受访者中，有 30.0%的人出现抑郁症状，大麻共同使用者比不报告当前大麻使用者（27.4%，<0.001）更有可能报告抑郁症状（36.5%）。抑郁症状与计划戒烟（ = 0.01）、多次尝试戒烟（<0.001）、对香烟非常上瘾的看法（<0.001）和强烈的吸烟冲动（ = 0.001）有关，而大麻使用与这些因素无关（所有 ≥ 0.05）。大麻使用与高风险的酒精消费有关（<0.001），而抑郁症状与这些因素无关（ = 0.1）。
共同使用者更有可能报告抑郁症状和高风险的酒精消费；然而，只有抑郁症状，而不是大麻使用，与更强的戒烟动机和对香烟的更大依赖有关。需要更深入地了解吸烟人群中大麻、酒精使用和抑郁之间的相互作用，以及这些因素如何随时间影响戒烟活动。
