Association of cannabis use with depression among cancer patients

Abstract

The rate of cannabis use by cancer patients is climbing. However, as the risk of mental illness caused by cannabis use in cancer patients has not been effectively evaluated, this study will analyze the association between cannabis use and depression in cancer patients. This study collected data from respondents to the National Health and Nutrition Examination Survey from 2005 to 2018. A total of 22,181 respondents self-reported information about cannabis use in questionnaire, of which 893 were diagnosed with cancer. We found that the rate of cannabis use among cancer patients increased each year from 2005 to 2018. We analyzed the association between cannabis use and depression in cancer patients by multivariable logistic regression. Results found that the current cannabis use had a significant positive correlation with increased risk of depression in cancer patients (OR = 2.135, 95% CI = 1.21-3.777, p = 0.009). In our stratified analysis, current cannabis use was associated with an increased risk of depression in cancer patients who were female, had a history of cocaine use, and initiated cannabis use after age 17. (OR = 1.981, 95% CI = 1.024-3.85, P = 0.043; OR = 3.19, 95% CI = 1.61-6.41, P < 0.001; OR = 2.236, 95% CI = 1.018-4.967, P = 0.045). In conclusion, the use of cannabis by cancer patients has an associated risk of depression and the cancer patients who currently use cannabis are more likely to have depression.

Keywords: Cancer patients; Cannabis use; Depression; National Health and Nutrition Examination Survey; Patient’s Health Questionnaire-9.

Fig. 1

Changes in the prevalence of cannabis use and the association of cannabis use status with depression in cancer patients. A. Changes in the prevalence of cannabis use among cancer patients in seven two-year cycles from 2005 to 2018. B. The relationship between different cannabis use statuses and depression in cancer patients.

Fig. 2

Subgroup analysis. The correlation between cannabis use status and depression in cancer patients in different subgroups was illustrated using a forest map. Gender stratification: A. Correlation between cannabis use and depression in female cancer patients; B. Association between cannabis use and depression in male cancer patients; C. Stratification of cocaine use history: correlation between cannabis use and depression in cancer patients without history of cocaine use; D. Association between cannabis use and depression in cancer patients with a history of cocaine use. The “Never” group was taken as a reference. According to the age of initial cannabis use, cancer patients with a history of cannabis use were divided into the ≥17 group and <17 group with the age of initial cannabis use having a cut-off value of 17; E. Correlation of cannabis use status with depression in cancer patients with initial cannabis use age ≥17; and F. Association between cannabis use status and depression in cancer patients with the age of initial cannabis use <17. The “Former” group was taken as a reference.

Fig. 3

Association between age of initial cannabis use with depression in cancer patients. A. Based on the logistic regression model, restrictive spline analysis showed the odds ratio between the age of initial cannabis use and depression; the cut-off value was determined according to the RCS curve; knots included the 5th, 35th, 65th, and 95th percentile of exposure factors; the model was fully adjusted according to social demographic factors, such as age and cannabis use status. B. The cancer patients who used cannabis were divided into the ≥17 group and <17 group, according to their age of initial cannabis use. Furthermore, cancer patients were grouped according to their cannabis use status and age of initial cannabis use. This was defined as the “Joint Group” and used as an exposure factor to analyze the correlation with depression. The ≥17 group and “Former” & ≥17 groups were taken as a reference, respectively. C. Taking cancer patients who have never used cannabis as a reference, the correlation between the “Joint Group” as an exposure factor and depression was analyzed.

Fig. 4

Sensitivity analysis. A. The association between cannabis use and depression was assessed in cancer patients with similar baseline characteristics as obtained by PSM. B. Assessing the association of the “Joint Group” (cancer participants grouped by cannabis use status and age at first cannabis use) with depression in PSM-matched participants. C and D. To analyze the correlation between cannabis use status and severe depression in cancer patients; the exposure factors included the cannabis use status and the age of initial cannabis use. The “Never” group was taken as the reference.

Fig. 5

Changes in prevalence of cannabis use among all participants and the relationship between cannabis use status and depression in all participants. A. Changes in the prevalence of cannabis use in all participants in seven two-year cycles from 2005 to 2018. B. The relationship between cannabis use status and depression in all participants. The status of cannabis use was divided into three groups: “Never”, defined as the group who never used cannabis; “Former”, defined as the group who used cannabis before and did not use cannabis in the past 30 days; “Current”, defined as the group who used cannabis in the past 30 days; The “Never” group was taken as the reference. C. All participants were matched by PSM to obtain a subset of participants with similar baseline characteristics, after which sensitivity analysis was conducted.