Main findings
In this population-based longitudinal study, four different trajectories of antidepressant use during 3 years before and after a suicide attempt were identified among all 3492 refugees and 58,950 Swedish-born individuals, respectively, who were 20–64-years-old when receiving specialised healthcare due to suicide attempt during 2009–2015 in Sweden. During this period, antidepressant use was constantly low (≤15 DDDs) for 65% of refugees. Among 6% of refugees, a low antidepressant use before a suicide attempt (< 100 DDDs) sharply increased after the attempt (around 650 DDDs). Two other trajectory groups had constant use of antidepressants at medium and high levels (22.5 and 6.6% of refugees had 110–190 and 630–765 DDDs, respectively). The method of index attempt and any use of psychotropic drugs during the year before index attempt influentially determined the differences among the trajectory groups in refugees. The patterns and composition of the trajectory groups and the association of these trajectories with the covariates among the Swedish-born were fairly similar to those among refugees.
The majority among refugees and the Swedish-born suicide attempters belonged to the ‘Low constant’ trajectory of antidepressant use. Although ‘low use’ was more prevalent among refugees (64.9%) than the Swedish-born (59.7%), the difference was quite small between these groups. The discrepancies in proportions of other psychotropic drug use among refugees and the Swedish-born during the year before suicide attempt were also marginal. It is not possible to make a direct comparison of these results with the literature because, to our knowledge, no previous studies investigated such trajectories before and after a suicide attempt. In a cross-sectional study in 2009, the prevalence of antidepressant use among refugees was considerably lower in refugees than in Swedish-born [28]. Much stronger differences between refugees and Swedish-born were found in a study focusing on young individuals with common mental disorders which reported considerably lower initiation of antidepressants in young refugees than their Swedish-born peers [29]. These contrasting findings regarding the degree of difference in antidepressant treatment in refugees, compared to host population, might be due to differences in study populations i.e. if the general population is investigated or different diagnostic groups. Also, discrepancies in socio-demographic factors (e.g. age group and socioeconomic status), as well as health status at baseline, might underlie the observed differences.
Some marginal differences were seen between refugees and the Swedish-born concerning the ‘Low increasing’ trajectories. There was a slightly lower proportion of refugees (5.9%) than the Swedish-born (10.8%) who belonged to these trajectory groups. Also, the increase of annual DDDs of antidepressants after the index attempt was much sharper among refugees than the Swedish-born. A possible explanation for this sharper increase in refugees than the Swedish-born can be that refugees in this group had a higher medical severity at baseline or received inadequate treatment preceding the attempt, which was then followed by higher dosages and adequate treatment with antidepressants after the attempt. Future studies should investigate if other factors, such as a higher number of reattempts among refugees who belonged to this trajectory group, can explain these findings.
Comparing the ‘Low constant’ and ‘Low increasing’ trajectories between refugees and the Swedish-born reveals that, in general, proportions of refugee suicide attempters using antidepressants were somewhat lower than that among the Swedish-born. This is in line with previous research that reported lower psychiatric healthcare use [9, 30] and treatment [29] in refugees than the host population. On the one hand, this may suggest that refugees have unmet needs for the treatment of their mental ill-health. On the other hand, lower use of antidepressants can be due to the side-effects of medication or mistrust in Western medicine. Furthermore, socio-cultural biases such as lack of proficiency in the Swedish language could have hampered expressing their mental distresses and therefore, they received fewer prescriptions. There can also be cultural differences in the expression of symptoms of mental ill-health leading to under-diagnosis and management. Higher levels of stigma towards mental ill-health and somatization of symptoms of underlying mental disorder may further contribute to such under-diagnosis and treatment. Furthermore, due to cultural influences, refugees may prefer alternative medicine like herbal remedies etc. over pharmacotherapy for treatment of mental disorders [31].
Considering so many potential barriers to healthcare access for refugees, the fact that we found only marginal differences in antidepressant use related to the ‘Low constant’ and ‘Low increasing’ trajectories and hardly any differences related to the two other trajectory groups at ‘Medium’ and ‘High’ levels between refugee and Swedish-born suicide attempters was somewhat surprising. Reasons for these comparable patterns might be due to the Swedish healthcare system managing quite well in bridging the treatment gap between refugees and Swedish-born particularly when it comes to suicide attempters. An alternative explanation might, however, be that refugees have a higher medical severity when they get specialised healthcare due to a suicide attempt due to the known barriers to specialised healthcare. This in turn might explain the comparable treatment rates to Swedish-born, i.e. relatively higher rates than what would be expected. Our data might not be sufficient to test this hypothesis as we don’t have access to information on the medical severity of the underlying disease or the severity of the suicide attempt. Further studies with information on suicide attempters with such clinical data are warranted to elucidate these associations. Finally, a third potential explanation for the apparent similarities rather than differences between the trajectory groups of antidepressant use among refugees and the Swedish-born could be due to the fact that most refugees (87%) in our cohort had been living in Sweden for longer than 5 years and a longer duration of residence was reported to be favourable for increasing access and use of psychiatric healthcare [28].
Association of covariates with identified trajectory groups
The socio-demographic, labour market marginalisation and clinical factors included in the full model explained around 43 and 39% of the variance across the trajectory groups among refugees and Swedish-born, respectively. It may suggest that, in determining the trajectory group belonging for refugees and the Swedish-born, there could be cultural and other unmeasured factors which will be worthwhile to investigate in future studies.
Any use of anxiolytic or hypnotic and sedative drugs during the year before index attempt was the most influential clinical factors in explaining the variability among the trajectory groups among refugees and the Swedish-born. The use of other psychotropic medication than antidepressants before the index attempt might here reflect a better knowledge and acceptance of the healthcare system or higher medical severity of the underlying mental disorder. We found that the difference in Nagelkerke pseudo R2 related to the use of hypnotics and sedatives was higher for refugees than in Swedish-born. This difference in pseudo R2 is based on a more skewed distribution across the trajectory groups in refugees than the Swedish-born; the biggest difference being among the ‘Low increasing’ trajectory group. This trajectory group also showed the biggest differences in temporal DDD level changes between refugees and Swedish-born and might, as previously mentioned, reflect differences regarding the medical severity.
Strengths and limitations
To the best of our knowledge, this is the first study where trajectories of antidepressant use before and after a suicide attempt among refugees and Swedish-born are explored. The main strength of this study is the population-based cohort design which allowed adequate statistical power for group-based trajectory analyses among a minority group i.e. refugee suicide attempters. Another strength is the use of high-quality [16,17,18,19,20] nationwide register data on DDDs of antidepressants and several covariates which also limited the possibility of recall bias and selection bias from non-response.
Our results should be interpreted within the context of some limitations. First, while previous surveys showed that approximately 50% of suicide attempters in Sweden require hospitalisation [32], the available data allowed only the inclusion of suicide attempters treated in specialised healthcare in this study. For refugees, this may have led to differential selection into the study population, because they probably had underreported suicidal behaviour differently than the Swedish-born population, due to higher levels of stigma associated with this behaviour [7]. Although this differential selection may have hampered the generalisability of our results, we believe that we were able to minimize this bias in both groups by including the events of undetermined intent (ICD-10 codes: Y10–Y34) as suicide attempts. Second, for 0.02% of refugees and Swedish-born individuals, the annual measure of use of antidepressants lacked data for the last 2 months during Y + 3. We think, though, that this has not affected our results. Moreover, the DDDs of antidepressants registered as purchases may not indicate the actual use of antidepressants. In Sweden, register data on antidepressants include prescriptions from primary and specialised outpatient healthcare, but not hospitalised care, suggesting some underestimation in our study. Furthermore, underuse in the form of non-compliance after purchase may occur and some individuals may overuse by obtaining unregistered drugs from abroad or via the internet. Also, we did not have information on the clinical indication for using an antidepressant. Antidepressants can be prescribed for other reasons than common mental disorders e.g. chronic pain. However, these conditions are often co-morbid and idioms of distress may present as somatic symptoms in refugees [33]. Finally, generalisability of our results to refugees, who arrived recently in a host country, may have been compromised because most individuals (87%) in this cohort of refugee suicide attempters had already been living in Sweden for longer than 5 years when they entered the cohort. Moreover, these results are not generalisable to asylum seekers awaiting legal status as refugees or to individuals living in refugee camps or in countries with substantially different healthcare systems than Sweden.