Challenges in researching migration status, health and health service use: an intersectional analysis of a South London community.

OBJECTIVES: This study aimed to investigate the associations between migration status and health-related outcomes and to examine whether and how the effect of migration status changes when it is disaggregated by length of residence, first language, reason for migration and combined with ethnicity. DESIGN: A total of 1698 adults were interviewed from 1076 randomly selected households in two South London boroughs. We described the socio-demographic and socio-economic differences between migrants and non-migrants and compared the prevalence of health-related outcomes by migration status, length of residence, first language, reason for migration and migration status within ethnic groups. Unadjusted models and models adjusted for socio-demographic and socio-economic indicators are presented. RESULTS: Migrants were disadvantaged in terms of socio-economic status but few differences were found between migrant and non-migrants regarding health or health service use indicators; migration status was associated with decreased hazardous alcohol use, functional limitations due to poor mental health and not being registered with a general practitioner. Important differences emerged when migration status was disaggregated by length of residence in the UK, first language, reason for migration and intersected with ethnicity. The association between migration status and functional limitations due to poor mental health was only seen in White migrants, migrants whose first language was not English and migrants who had moved to the UK for work or a better life or for asylum or political reasons. There was no association between migration status and self-rated health overall, but Black African migrants had decreased odds for reporting poor health compared to their non-migrant counterparts [odds ratio = 0.15 (0.05-0.48), p < 0.01]. CONCLUSIONS: Disaggregating migration status by length of residence, first language and reason for migration as well as intersecting it with ethnicity leads to better understanding of the effect migration status has on health and health service use

Reconsidering the reasons for heightened inflammation in major depressive disorder

Background Increased circulating pro-inflammatory markers have repeatedly been associated with major depressive disorder (MDD). However, it remains unclear whether inflammation represents a causal mechanism for MDD, or whether the association is influenced by confounding factors such as body mass index (BMI). Methods To better understand this complex relationship, we generated polygenic risk scores (PRS) for MDD and BMI in a population cohort and attempted to isolate the impact these potential risk factors have on adulthood inflammation. Peripheral blood samples were collected as part of the South East London Community Health study, where we generated individualized PRS for MDD and BMI and quantified inflammatory markers using multiplex ELISA-based technology. We performed linear regressions to investigate the effects of PRS for MDD and BMI on inflammatory marker levels. Results Out of 35 inflammatory markers, we found a nominal effect of PRS for MDD on interleukin-10. We also found a significant positive effect of BMI on nine inflammatory markers, of which the two most strongly affected markers, interleukin-6 (IL-6) and C-reactive protein (CRP), were also nominally predicted by BMI PRS. Limitations The study utilized a cross-sectional design with a moderately sized sample. Conclusions Our findings suggest there may not be a shared genetic mechanism contributing to MDD and higher inflammatory marker levels. However, there may be shared genetic etiology between BMI and adulthood levels of CRP and IL-6. Therefore, polygenic risk scores for BMI may represent a useful indicator for heightened levels of inflammation in adulthood

Importance of thinking locally for mental health: data from cross-sectional surveys representing South East London and England.

Reliance on national figures may be underestimating the extent of mental ill health in urban communities. This study demonstrates the necessity for local information on common mental disorder (CMD) and substance use by comparing data from the South East London Community Health (SELCoH) study with those from a national study, the 2007 English Adult Psychiatric Morbidity Study (APMS)

Challenges in the retrospective assessment of trauma:comparing a checklist approach to a single item trauma experience screening question

Background Research on trauma and its impact on mental health typically relies on self-reports which can be influenced by recall bias and an individual’s subjective interpretation of events. This study aims to compare responses on a checklist of life events with a trauma experience screening question, both of which assessed trauma experience retrospectively. Methods A community sample of adults were asked about life events from a checklist before asking them whether they ever had a trauma experience, i.e. “an event that either puts them or someone close to them at risk of serious harm or death”. Results Less than half of the sample who reported at least one life event on the checklist that qualified as a trauma reported a trauma experience that they perceived put them or close others at risk of serious harm. Women responders, those reporting early life traumas, and a greater number of lifetime trauma events were more likely to report a trauma experience. Current symptoms of Common Mental Disorder did not account for differences in reporting of trauma experiences. Conclusions Epidemiological approaches which require participants to make subjective judgement on the severity of the trauma experience will capture individual differences that we have shown are influenced by gender and previous trauma experience

Recurrence of Depression in Relation to History of Childhood Trauma and Hair Cortisol Concentration in a Community-Based Sample.

Background: Childhood trauma represents a risk factor for developing depression with increased rates of recurrence. Mechanisms involved include a disturbed regulation of the hypothalamic–pituitary–adrenal (HPA) axis. Hair cortisol concentration (HCC) is a measure of long-term HPA axis activity with less interference from circadian and confounding factors. However, no study has so far used HCC to investigate the role of childhood trauma in recurrent pattern of depressive symptoms. Methods: A community-based sample of 500 participants was recruited, and depression was assessed at 3 time points using the Revised Clinical Interview Schedule. The Childhood Trauma Questionnaire was administered to identify a history of childhood trauma. Hair samples were obtained from 144 participants for analysis of cortisol. Results: Patients with recurrent depression had higher rates of childhood trauma compared to participants with no depression. Participants with current-only depression had increased HCC compared to the no depression group, while this was absent in participants with recurrent depression. Within the depressed group (both current-only and recurrent depression), those with a history of childhood physical abuse had lower HCC when compared to those with no such history. Conclusions: Our findings show that retrospectively reported childhood trauma is associated with protracted trajectories of depression and a distinct pattern of long-term HPA axis activity

Discrimination and common mental disorder among migrant and ethnic groups:findings from a South East London Community sample

Purpose Few studies have examined discrimination and mental health in the UK, particularly by migrant status and in urban contexts with greater demographic diversity. This study aims to (1) describe the prevalence of discrimination experiences across multiple life domains; (2) to describe associations between discrimination experiences and common mental disorder (CMD); (3) to determine whether or not the relationship between discrimination and CMD varies by migrant status and ethnicity. Methods Data on major, anticipated and everyday discrimination and CMD symptoms were collected from an ethnically diverse prospective sample of 1052 participants followed up from 2008 to 2013 in the South East London Community Health study, a population-based household survey. Results With few exceptions, discrimination was most prevalent among those in the Black Caribbean group. However, those in the White Other ethnic group had similar or greater reporting major and anticipated discrimination to Black or mixed ethnic minority groups. The effects of discrimination on CMD were most pronounced for individuals who had recently migrated to the UK, an ethnically heterogeneous group, and for Black and Mixed ethnic minority groups in partially adjusted models. Prior CMD accounted for differences between the Mixed and White British ethnic groups, but the strength of the association for the most recent migrant group and the Black ethnic groups remained two or more times greater than the reference groups. Conclusions The strength of the relationship suggests a need for more consideration of migration status along with ethnicity in examining the impact of discrimination on mental disorder in community and clinical samples

Genetic Risk for Psychiatric Disorders and Telomere Length

Background: Previous studies have revealed associations between psychiatric disorder diagnosis and shorter telomere length. Here, we attempt to discern whether genetic risk for psychiatric disorders, or use of pharmacological treatments (i.e., antidepressants), predict shorter telomere length and risk for aging-related disease in a United Kingdom population sample. Methods: DNA samples from blood were available from 351 participants who were recruited as part of the South East London Community Health (SELCoH) Study, and for which whole-genome genotype data was available. Leukocyte telomere length was characterized using quantitative polymerase chain reactions. Individualized polygenic risk scores for major depressive disorder (MDD), bipolar disorder (BD), and schizophrenia (SCZ) were calculated using Psychiatric Genomics Consortium summary statistics. We subsequently performed linear models, to discern the impact polygenic risk for psychiatric disorders (an etiological risk factor) and antidepressant use (common pharmacological treatment) have on telomere length, whilst accounting for other lifestyle/health factors (e.g., BMI, smoking). Results: There were no significant associations between polygenic risk for any of the psychiatric disorders tested and telomere length (p > 0.05). Antidepressant use was significantly associated with shorter telomere length and this was independent from a depression diagnosis or current depression severity (p ≤ 0.01). Antidepressant use was also associated with a significantly higher risk of aging-related disease, which was independent from depression diagnosis (p ≤ 0.05). Conclusion: Genetic risk for psychiatric disorders is not associated with shorter telomere length. Further studies are now needed to prospectively characterize if antidepressant use increases risk for aging-related disease and telomere shortening, or whether people who age faster and have aging-related diseases are just more likely to be prescribed antidepressants