Insights on Canadian Society
Examining variations in immigrants’ lower risk of suicide-related behaviours

by Fei-Ju Yang, Linlu Zhao and Nicole Aitken

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Introduction

Suicide is an ongoing public health concern in Canada and globally. Suicide-related behaviours exist on a spectrum of severity that includes suicide ideation (thoughts about taking action to end one’s life), attempted suicide (a potentially self-injurious behaviour associated with at least some intent to die), and completed suicide (a fatal self-injurious act with some evidence of intent to die).^Note   An estimated 11.8% of Canadians reported suicidal thoughts in their life, 2.5% had suicidal thoughts in the past year, and 3.1% made a suicide attempt in their lifetime. Relative to other causes of death, death by suicide is a relatively rare occurrence in Canada.^Note   Approximately 4,000 deaths by suicide occur in Canada every year^Note  out of approximately 285,000 total annual deaths. Although death by suicide is a relatively rare occurrence, these suicides could have long-lasting impact on the family members of the deceased including grief and bereavement.^Note 

Immigrants generally have a lower risk of suicide-related behaviours compared to non-immigrants in immigrant-receiving countries such as Canada.^Note  Long-term immigrants who have resided in Canada for more than 10 years typically have higher rates of suicide-related behaviours than recent immigrants, possibly as a result of prolonged exposure to post-migration-related stressors, including social isolation, discrimination, language barriers, and unemployment.^Note  

However, the immigrant population in Canada is not a homogeneous group, the origins of immigrants to Canada are increasingly diverse.^Note  When the heterogeneity of immigrant populations is considered, it becomes clear that certain immigrant populations are disproportionately affected by suicide-related behaviours. For instance, a Statistics Canada study found that suicide mortality rates for immigrants generally were lower compared with the Canadian-born population but suicide rates varied by birthplace. Those born in Europe and Oceania had suicide rates similar to that of the Canadian-born population and those born in Asia and Africa had the lowest rates.^Note  Country of origin analysis of immigrants living in Ontario also showed a wide range in suicide mortality rates.^Note   This variability among immigrants of different origins can be seen in other immigrant-receiving countries for risk of suicide ideation, attempted suicide, and completed suicide.^Note  Suicide-related behaviors are an interaction of pre-migration factors (e.g., home country’s investment in mental health services, religion, etc.) and post-migration factors (e.g., social support, linguistic acquisition, employment, access to health care in destination countries etc.).

It has been over 20 years since the last national release of disaggregated suicide risk by immigrant status in Canada. This national level analysis was performed using three-year combined death data centered around Census years 1991 and 1996.^Note   There is thus a need to conduct a disaggregated analysis using more contemporary data given the shifting patterns of country of origin of immigrants and socioeconomic and sociocultural changes over time. The purpose of this study is to provide estimates of rates of suicide ideation and suicide mortality of immigrants in Canada. Analogous analyses were conducted among Canadian-born individuals for reference. It is important to emphasize that within the Canadian-born population, there is much diversity, such as possible differences within and between racialized groups, as well as between Indigenous and non-Indigenous people.

Since national immigrant suicide-related behaviour has not been recently studied, the study aims to provide contextual information on groups in this population, particularly across life stages. Guided by the social determinants of health framework,^Note  the descriptive analysis disaggregates suicide-related behaviours by sociodemographic and socioeconomic factors, including age, sex,^Note  income, household level education; and for immigrants, time since migration and country of birth (see Data sources, methods and definitions). The impacts of these factors on suicide-related behaviours are investigated using regression modelling.

This study analyzes both suicide ideation and suicide mortality. To understand suicide ideation, the analysis used the 2015, 2016 and 2019 Canadian Community Health Survey (CCHS) pooled cohort. For the analysis of suicide mortality, the 2006 Canadian Census Health and Environment Cohort (CanCHEC) was used.^Note 

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In total, 1 in 16 Canadian immigrants had suicidal thoughts in their lifetime

Overall, 6% of Canadian immigrants experienced thoughts of suicide at some point in their lives. This was considerably lower than the 14% of Canadian-born persons who seriously considered suicide in their lifetime. Past-year suicide ideation was also less prevalent among immigrants (1.5%) than their Canadian-born counterparts (3.1%) (Chart 1).

To understand differences in suicide ideation within immigrant and Canadian-born populations, sociodemographic and socioeconomic characteristics were examined (Table 2).^Note  For immigrants, youth aged 15 to 24 years were the most likely to report past-year suicide ideation, with 4% reporting thoughts of suicide within the last year. This was more than 2.5 times the proportion reported for immigrants overall (1.5%). There were no significant differences by sex, region of birth, time since migration, household education and household income among immigrants.

For the Canadian-born population, youth also had the highest rate of past-year suicide ideation, at 6.5%. In addition, 3.6% of the 25-to-39-year-olds reported past-year suicide ideation, which was higher than the 2% among 40-to-64-year-olds. Unlike immigrants, there were differences across various other socio-demographic characteristics. A higher proportion of Canadian-born females (3.4%) reported past-year suicide ideation than Canadian-born males (2.7%). In addition, Canadian-born individuals from households with no post-secondary education, as well as households in the bottom income quintile reported higher past-year suicide ideation (3.9% and 6.2% respectively).

Additional comparisons between immigrants and the Canadian-born population indicates that for both sexes, the Canadian-born population had higher prevalence of past-year suicide ideation. In each age group, immigrants had lower prevalence of past-year suicide ideation than the Canadian-born population, except for older immigrants aged 65 years and older, for whom no significant difference between the two groups was found.

Anxiety or mood disorders were associated with suicide ideation among both immigrants and Canadian-born individuals

Having a diagnosed mood disorder or anxiety was associated with a higher prevalence of past-year suicide ideation for both Canadian immigrants and Canadian-born individuals. In general, the prevalence of anxiety and mood disorders is about 2 times greater among Canadian-born than immigrants (Appendix A).  For immigrants with a mood disorder, such as depression, bipolar disorder, mania or dysthymia, 14% had past-year suicide ideation. Similar elevated levels were seen among immigrants with an anxiety disorder, with 11% having past-year suicide ideation. For Canadian-born individuals, the proportion with past-year suicide ideation was 18% for those diagnosed with mood disorders and 14% for those with anxiety disorders.

Having a mood disorder or anxiety was the strongest risk factor of suicide ideation among immigrant and the Canadian-born populations

Multivariable logistic regression modelling examined associations between sociodemographic, socioeconomic and mental health factors on past-year suicide ideation for Canadian immigrants and the Canadian-born population. Separate models were estimated for the immigrant and the Canadian-born populations as the influence of risk factors on suicide ideation may be different for these two populations.

When all risk and protective factors for suicide ideation were considered simultaneously, results suggested that having either an anxiety or mood disorder, which are strongly correlated with each other, was the strongest risk factor for both immigrant and Canadian-born populations (Table 3).^Note  After controlling for a range of socio-economic factors, the odds of suicide ideation was about 10 times greater among those with an anxiety or mood disorder compared to those without. Sex was not associated with past-year suicide ideation in the fully adjusted model for both populations, after accounting for impact of mental health disorders.

The fully adjusted model for both populations suggests that the age pattern of past-suicide ideation varied by immigrant status, when controlling for other sociodemographic factors. Being very young was a risk factor for past-year suicidal ideation among immigrants. Compared to 40-to-64-year-olds, immigrants aged 15 to 24 were about 4 times more likely to have thought about killing themselves in the past year. The Canadian-born population had a larger age range at risk. Plus, the Canadian-born seniors were at less risk than the working-aged reference group.

In addition, among immigrants, time since migration was a risk factor on suicide ideation. Specifically, long-term immigrants, defined as those who immigrated to Canada over 10 years ago, were more likely to report past-year suicide ideation than recent immigrants.

For the Canadian-born population, socioeconomic factors, such as being in the lowest household income quintile and having no postsecondary education at the household level, remained risk factors after taking into account different socio-demographic factors. These same risk factors did not have significant associations with past-year suicide ideation for immigrants.

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Age-standardized suicide mortality rate lower among immigrants compared to Canadian-born individuals

The following section presents patterns of suicide mortality among immigrants and Canadian-born individuals based on the 2006 CanCHEC cohort with 10 years of death data follow-up. In the following analysis, protective or risk factors similar to the CCHS data, if available on CanCHEC, were used for descriptive and multivariable analysis. The goal is to identify whether past-year suicide ideation and suicide mortality generally share the same risk or protective factors.

The findings are presented as an estimated number of deaths by suicide per 100,000 person-years at risk. The person-year concept is often used in cohort studies and represents unit of time when individuals are at risk of dying, and can be roughly understood as persons per year.

Mirroring the lower rate of suicide ideation, the prevalence of suicide mortality was lower among immigrants compared to the Canadian-born population (Table 5). The age-standardized suicide mortality rate for immigrants was 7.5 per 100,000 person-years at risk and 13.9 per 100,000 person-years for Canadian-born individuals. However, variations in the suicide mortality rates within the populations emerged when disaggregated by sociodemographic and socioeconomic factors.

Immigrants born in Western Europe had the highest suicide mortality rate among immigrants

For both immigrant and Canadian-born populations, suicide rates were higher among males than females, contrasting patterns in suicide ideation.  For immigrant men, the suicide rate was 2.75 times higher compared to immigrant women (11 versus 4 per 100,000 person-years). Similarly, it was 3 times higher among Canadian-born men compared to Canadian-born women (22 versus 7 per 100,000 person-years). The apparent gender paradox in ideation and suicide mortality is well-documented.^Note  Men tend to use more lethal methods to kill themselves than women, while women tend to report higher suicide thoughts and attempts.

The risk of suicide varied among immigrants from different regions. Immigrants born in Western Europe had the highest suicide mortality rate at 15 suicides per 100,000 person-years. Immigrants from other regions had suicide mortality rates ranging from 6 to 11 per 100,000 person-years (Table 5).

The variation in suicide mortality by region of birth is likely influenced by the interplay of birth country environment and post-migration integration in Canada. According to the World Health Organization, risk of suicide varies by region, with African, European, and South-East Asia regions having higher rates than the global average.^Note  Although immigrants’ socioeconomic and health characteristics largely differ from those of the population in their birth country, they still carry the risk of suicide in their birth country including stigmatization of mental health difficulties.^Note 

After migration, immigrants are impacted by another set of risk factors in the destination country, including language barriers, poor job outcomes, and barriers to health care.^Note The impact of poor social integration on health is usually not immediate. It could take many years of persistent high-effort coping to impact the health of immigrants who experience low social integration.^Note 

Along with sex and region of birth, economic family income played a role in risk for immigrants. Those in the lowest income quintile had a suicide mortality rate 1.3 times higher than those not in the lowest income quintile (9 versus 7 per 100,000 person years). The influence of economic conditions on suicide mortality among immigrants in this study but not on suicide ideation, may be related to differences in the composition of immigrants in the two data sources. For example, the CanCHEC database contains a greater share of European immigrants and long-term immigrants compared to the CCHS.  For this reason, it is not recommended to compare results across the two data sources.

Some researchers argue that objective economic conditions have weaker associations with mental health than ‘subjective social status’ for immigrants because recent immigrants and older immigrants  do not necessarily compare themselves to the host country population.^Note  However, for immigrants who acculturate to the host country over time, their internal reference group can switch to the native-born population and the sense of relative deprivation may be stronger.

The suicide mortality rates for immigrants, however, did not differ by household education. This result indicates that, for immigrants, the protective effect of postsecondary education on suicide-related behaviours was weak. According to a recent study, the experience of over-education was found to be more prevalent among working-aged immigrants, where 62% of the recent immigrants and 48% of the established immigrants did not find jobs that matched their educational credentials, compared to 40% for the Canadian-born population.^Note  As a result, it points to the possibility that the experience of underemployment reduces the protective effect of postsecondary education on mental health for immigrants, who are generally well-educated in Canada.^Note 

Similar to the immigrant population, the suicide mortality rates were higher for Canadian-born from a household in the lowest income quintile (23 per 100,000 person years). However, unlike the immigrant population, risk was higher for Canadian-born in households without a post-secondary education (16 per 100,000 person years). 

Although there were similarities in the patterns between the Canadian immigrant and Canadian-born populations for sex and income, the magnitude of difference was smaller for immigrants. For instance, the male-to-female ratio in suicide rate was 3.2 among the Canadian-born population and 2.7 for immigrants. Income-related health inequalities also appeared to be smaller among the immigrants. For instance, the rate ratio between those in the lowest income quintile and the highest quintile was larger for the Canadian-born than the immigrants (1.9 times versus 1.3 times).

Immigrants aged 25 to 39 had the lowest suicide mortality rate among immigrants

Age-specific patterns in suicide mortality differed from suicide ideation. While young people tended to have higher rates of suicidal thoughts, they were not necessarily at higher risk of dying by suicide.  (Table 6).

For immigrants, 40-to-64-year-olds were more at risk of suicide mortality, but only compared to their counterparts aged 25 to 39. Rates of suicide mortality for working-aged immigrants were similar to the youngest and oldest age groups. For the Canadian-born population, 40-to-64-year-olds had the highest suicide mortality rates (17 per 100,000 person years) compared to other age groups.

Additional comparison between immigrants and the Canadian-born population indicates that the two groups were equally vulnerable to late-life suicide. Moreover, suicide mortality among immigrant youth did not differ from that of the Canadian-born youth.

Sex, age, region of birth, and income quintile remain strong risk factor of immigrant suicide mortality, after accounting for other factors

To examine the role of sociodemographic and socioeconomic factors in the risk of death by suicide among immigrants and the Canadian-born, multivariable analysis was conducted. Sociodemographic and socioeconomic variables that were identified as possible risk factors for suicide-related behaviours across all life stages were entered into the model sequentially to adjust the hazard ratio of suicide mortality. The hazard ratios can be understood as the relative risk of suicide mortality based on certain characteristics. 

Overall, the models for both the immigrant and the Canadian-born populations largely reflect the descriptive statistics. After accounting for the other factors, both immigrant and Canadian-born males had a risk of suicide mortality approximately three times higher than their female counterparts (Table 7).

Among the immigrant population, the models suggest that sex, age, region of birth, and income quintile remained factors associated with a higher risk of suicide mortality. Likewise, among the Canadian-born population, sex, age, household-level education, and income quintile were factors associated with a higher risk of suicide mortality. One of the main limitations of this model is the lack of data on mental health disorders, in light of the positive correlation between anxiety or mood disorders and the risk of suicide ideation.

Conclusion

Overall, Canadian immigrants had lower rates of suicide ideation and suicide mortality than the Canadian-born population. Yet, there was heterogeneity within this broader pattern, as the disaggregated results illustrated variations in suicide mortality by region of birth. This is consistent with previous studies, which indicate that the overall health patterns of immigrants as an aggregated group do not extend to immigrants from certain regions.^Note 

The immigrant population in Canada represents a diverse group, and as such, disaggregation of data is necessary to identify variations in suicide-related behaviours. This, in turn, can create opportunities for targeted suicide prevention strategies. The study highlighted that, while immigrant and Canadian-born population share some broader patterns in suicide-related behaviours, there are also some unique patterns.  After accounting for socio-demographic and economic factors, for both immigrants and Canadian-born individuals, sex was not associated with differences in past-year suicide ideation but males had roughly three times higher suicide mortality rates than those of females. This sex gap was similar to previously published Canadian statistics.^Note 

Having an anxiety or mood disorder was found to be the strongest risk factor for past-year suicide ideation for both populations, consistent with other studies indicating a negative influence of mental disorders on suicide-related behaviours.^Note  Low household income was associated with a higher risk of suicide ideation for the Canadian-born only, but lower income was associated with suicide mortality for both populations.

These disaggregated results further indicate that the relationship between age and suicide-related behaviours varied by immigrant status. Though for both populations, past-year suicide ideation peaked among youth. Immigrants in all age groups reported lower rates of past-year suicide ideation compared to the Canadian-born population, except for senior immigrants.

In terms of suicide mortality, young and older immigrants were as likely to die by suicide, while young Canadian-born persons were less likely than their older working-aged counterparts to die by suicide. These age patterns in suicide mortality have also been reported in other Canadian studies.^Note  The relationship between age and suicide-related behaviours can be related to other age-related psychosocial factors not captured in this study, including self-esteem, mastery, and social support.^Note  Additionally, the analysis suggested education at the household-level was associated with suicide-related behaviours for Canadian-born population but not for immigrants. It is noteworthy that measures for mental disorders were not available for the analysis of suicide mortality. Given its important link to suicide ideation, it is recommended that future studies look into the possibility of including direct or proxy measures of mental health when analyzing suicide mortality.

There are several factors that influence mental health and suicide-related behaviours that were not included in this study. These included admission class (economic-class, family-class, or refugee), period of migration, acculturative stress, psychosocial resources, substance use, religion, adverse childhood experiences and racialization.^Note  In addition, since the goal of this study was to study suicide-related behaviours for a nationally representative population aged 15 years and over, only protective and risk factors that apply across all stages of life were included. As a result, job status and marital status were excluded in this study since youth may not have a job or be married.

Protective and risk factors likely vary by age group in a subpopulation. It is also important to develop suitable measures of protective and risk factors for specific subpopulation. For instance, for working-age immigrants, over-education or job-related stress could be risk factors for mental health, while for older adults, the risk factors could be social isolation and language barriers. Future suicide-related research should be tailored to specific age groups to help identify important protective and risks factors for different stages of life. In addition, factors such as racialization, as well as sexual and gender diversity should be considered.

It must be recognized that low suicide-related behaviours may not represent good mental health.  According to the WHO, “mental health is more than the absence of mental disorder. It exists on a complex continuum, which is experienced differently from one person to the next, with varying degrees of difficulty and distress and potentially very different social and clinical outcomes”.  In fact, previous studies indicate that immigrants typically had lower distress or lower depression, yet they had similar level of self-rated mental health, or lower quality of life than the Canadian-born population.^Note  When immigrants experience poor mental health, they were also less likely to consult mental health professionals than the Canadian-born population.^Note  As such, it is important to acknowledge that there is no ‘one-size-fits-all’ approach to mental health promotion or suicide prevention.

Fei-Ju Yang and Nicole Aitken are analysts at the Centre for Health Data Integration (CHDI) at Statistics Canada. Linlu Zhao is an analyst at Public Health Agency of Canada.

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