Social isolation, loneliness and depression in young adulthood: a behavioural genetic analysis

Abstract

PurposeTo investigate the association between social isolation and loneliness, how they relate to depression, and whether these associations are explained by genetic influences.MethodsWe used data from the age-18 wave of the Environmental Risk Longitudinal Twin Study, a birth cohort of 1116 same-sex twin pairs born in England and Wales in 1994 and 1995. Participants reported on their levels of social isolation, loneliness and depressive symptoms. We conducted regression analyses to test the differential associations of isolation and loneliness with depression. Using the twin study design, we estimated the proportion of variance in each construct and their covariance that was accounted for by genetic and environmental factors.ResultsSocial isolation and loneliness were moderately correlated (r = 0.39), reflecting the separateness of these constructs, and both were associated with depression. When entered simultaneously in a regression analysis, loneliness was more robustly associated with depression. We observed similar degrees of genetic influence on social isolation (40 %) and loneliness (38 %), and a smaller genetic influence on depressive symptoms (29 %), with the remaining variance accounted for by the non-shared environment. Genetic correlations of 0.65 between isolation and loneliness and 0.63 between loneliness and depression indicated a strong role of genetic influences in the co-occurrence of these phenotypes.ConclusionsSocially isolated young adults do not necessarily experience loneliness. However, those who are lonely are often depressed, partly because the same genes influence loneliness and depression. Interventions should not only aim at increasing social connections but also focus on subjective feelings of loneliness.

Breaking down the genetics of depression using brain endophenotypes

“…AE models showed the best fit to the data and shared environment could not explain the association (p-value<1.7e-03). We also replicated that self-reported measures of stress are genetically correlated with the depression score (Supplementary Document 33) [8,9].…”

“…Some studies have described three genetic factors that explain the variety of symptomatic profiles [6], others have suggested that environmental risk factors (e.g. childhood trauma and stressful life events) could define sub-types of the disorder [7][8][9], or have proposed to break down MDD by sex to reflect differences in heritability and prevalence [5,13,447]. More recently, some studies have suggested differentiating cases 247 based on appetite/weight gain (atypical depression) or loss (typical) based on different patterns of association with BMI and SCZ [620].…”

“…In addition, environmental risk factors (e.g. childhood trauma and stressful life events) also contribute to the heterogeneity of MDD, and may even define genetic sub-types [7][8][9]. Furthermore, symptoms of depression may also be present in other psychiatric disorders (and conversely), making the diagnostic boundaries overlap.…”

“…These include: neuroticism [394], personal life events [9] and perceived social support [7,8]. MRI brain measurements represent promising endophenotypes, being objective (not self reported), reliable [398] and heritable [27,399].…”

‘Life in the Travelling Circus’: A Study of Loneliness, Work Stress, and Money Issues in Touring Professional Golf

“…However, such studies have focussed on sports that have a greater level of stability in their migratory moves, rather than those that involve almost constant 'circulatory' geographical movements such as golf where issues are further exacerbated. It is important to consider the impact of feelings of loneliness on sport migrants' well-being, particularly given the large amount of research that identifies a strong relationship between loneliness, isolation, and psychological health in relation to depression (Alpass & Neville, 2003;DiTommaso & Spinner, 1997;Luanaigh & Lawlor, 2008;Matthews et al, 2016). Unsurprisingly, research on loneliness tends to focus on 'elderly' populations, however, given it was a large feature of the lives of the golfers in this study, it is important to consider the links to mental health and well-being within sports migrants' lives.…”