OBJECTIVE: To assess the prevalence and association of depression among Canadian adults with cancer in a population-based context.
METHODS: The Canadian Community Health Survey (CCHS) (2015-2016) was accessed and adult participants with cancer who completed the Personal Health Questionnaire (PHQ9) were included in the current analysis. Multivariable logistic regression was conducted to elucidate the factors associated with the development of depression. An additional multivariable logistic regression analysis was conducted to evaluate the association of depression with ever contemplating suicide (suicidal ideation).
RESULTS: A total of 867 participants with cancer have completed PHQ9 were included in the current analysis (including 603 participants (69.6%) without depression (PHQ9 ≤ 4) and 264 participants (30.4%) with depression (PHQ9> 4)). Moreover, 92 participants (10.6%) fulfill the criteria for moderate/severe depression (PHQ9>9). Participants with depression were more likely to have visited a mental health professional in the last 12 months (33.7% versus 9.5%; P<0.001), to have been diagnosed with a mood disorder (24.3% versus 4.6%; P< 0.001) and to have a suicidal ideation (22.4% versus 7.3%; P<0.001). The following factors were associated with the presence of depression (PHQ9>4), female sex (OR for males versus females: 0.56; 95% CI: 0.34-0.93; P=0.02); poor self-perceived health (OR for excellent health versus poor health: 0.12; 95% CI: 0.02-0.62; P=0.01) and poor self-perceived mental health (OR for excellent mental health versus poor mental health: 0.02; 95% CI: <0.01-0.24; P<0.01). Additional multivariable logistic regression analysis showed that depression (PHQ9>4) was associated with a higher probability of suicidal ideation (OR for no depression versus depression: 0.43; 95% CI: 0.21-0.91; P=0.02).
CONCLUSIONS: Depression seems to be an underdiagnosed and possibly undertreated comorbid condition among Canadian adults with cancer. This increases the risk of suicidal ideation (which might lead to completed suicide) among affected cancer patients.