Explaining the gaps in psychological distress and suicidal behaviours between non-Indigenous and Indigenous adults living off-reserve in Canada: a cross-sectional study

Abstract

Background: Indigenous people are disproportionately affected by mental health issues in Canada. We investigated factors underlying the difference in psychological distress and suicidal behaviours between non-Indigenous and Indigenous populations living off-reserve in Canada.

Methods: We conducted a cross-sectional study using data from the 2012 Canadian Community Health Survey - Mental Health. Respondents were aged 18 years and older. We measured the variation in psychological distress (10-item Kessler Psychological Distress Scale scores, ranging from 10 [no distress] to 50 [severe distress]) and the prevalence of lifetime suicidal ideation and suicide plan between the Indigenous and non-Indigenous populations and explained these differences using the Blinder-Oaxaca approach.

Results: The overall response rate for the survey was 68.9%, comprising 18 300 respondents (933 Indigenous and 17 367 non-Indigenous adults). We found lower mean psychological distress scores among non-Indigenous people than among Indigenous people (15.1 v. 16.1, p < 0.001) and a lower prevalence of lifetime suicidal ideation (9.2% v. 16.8%, p < 0.001) and plan (2.3% v. 6.8%, p < 0.001). We found that if socioeconomic status among Indigenous people were made to be similar to that of the non-Indigenous population, the differences in mean psychological distress scores and prevalence of lifetime suicidal ideation and suicide plan would have been reduced by 25.7% (women 20.8%, men 36.9%), 10.2% (women 11.2%, men 11.9%) and 5.8% (women 7.8%, men 8.1%), respectively.

Interpretation: Socioeconomic factors account for a considerable proportion of the variation in mental health outcomes between non-Indigenous and Indigenous populations in Canada. Improving socioeconomic status among Indigenous people through plans like income equalization may reduce the gap in mental health outcomes between the 2 populations in Canada.

Figure 1:

Percentage point contribution of explained and unexplained components to the differences in psychological distress scale and the prevalence of lifetime suicidal ideation and suicide plan between non-Indigenous and Indigenous adults living off-reserve in Canada. Percentage point contributions of explained component were calculated by dividing the sum of the contribution of all variables in each category by the total difference in the corresponding mental health outcome. Some percentages do not add up to 100 as a result of rounding.