Month: February 2020

Genetic Overlap Between Type 2 Diabetes and Depression in a Sri Lankan Population Twin Sample

Kan, Carol MRCPsych, PhD; Jayaweera, Kaushalya MD; Adikari, Anushka MD; Siribaddana, Sisira FRCP; Zavos, Helena M.S. PhD; Harber-Aschan, Lisa PhD; Sumathipala, Athula PhD; Hotopf, Matthew PhD, FRCPsych; Ismail, Khalida MRCPsych, PhD; Rijsdijk, Frühling PhD

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Psychosomatic Medicine  Volume 82 – Issue 2

doi: 10.1097/PSY.0000000000000771

Abstract

Objective 

Results from twin studies examining the genetic overlap between type 2 diabetes and depression are currently inconclusive. This question has not been addressed in non-Western populations. We aimed to examine whether there are common genetic factors between type 2 diabetes and depression in a Sri Lankan population using genetic model-fitting analysis.

Method 

The Colombo Twin and Singleton Study–Phase 2 consists of 2019 singletons, and 842 monozygotic and 578 dizygotic twin pairs. The primary outcomes were self-reported type 2 diabetes diagnosis and Beck Depression Inventory scores. Standard bivariate twin models were fitted to estimate the genetic and environmental (co)variance of type 2 diabetes and depression.

Results 

In the best-fitting model, the phenotypic correlation between type 2 diabetes and depression was significant in female individuals only (r = 0.15 [0.08–0.21]). This association was primarily attributed to a significant genetic correlation between the traits (rA = 0.53 [0.19–0.98]).

Conclusions 

In female individuals, but not male individuals, we found a significant genetic overlap between type 2 diabetes and depression in the context of a modest phenotypic correlation.

Website:

Genetic Overlap Between Type 2 Diabetes and Depression in a… : Psychosomatic Medicine (lww.com)

PDF:

Genetic Overlap Between Type 2 Diabetes and Depression in a Sri Lankan Population Twin Sample : Psychosomatic Medicine (lww.com)

The relationship between independent and dependent life events and depression symptoms in Sri Lanka: a twin and singleton study


Helena M. S. Zavos, Bethan Dalton, Kaushalya Jayaweera, Lisa Harber-Aschan, Gayani Pannala, Anushka Adikari, Stephani L. Hatch, Sisira Siribaddana, Athula Sumathipala, Matthew Hotopf & Frühling V. Rijsdijk

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Social Psychiatry and Psychiatric Epidemiology, Volume 55, Pages 237 – 249

doi:https://doi.org/10.1007/s00127-019-01765-z

Abstract

Purpose
Life events have been associated with a variety of mental health conditions including depression. There is a scarcity of research in South Asia exploring the aetiology of independent and dependent life events and their relationship with depression symptoms. This study aimed, in a Sri Lankan population, to identify the socio-demographic correlates and genetic and environmental influences on independent and dependent life events and their relationship with depression.

Methods
Questionnaire data came from the Colombo Twin and Singleton Follow-up Study, CoTaSS-2 (N = 3969), a population study of Sri Lankan twins and singletons. Lifetime-ever independent and dependent life events were measured using a questionnaire and depressive symptoms using the Revised Beck’s Depression Inventory. Structural Equation Model-fitting analyses explored the genetic and environmental influences on life events and depression.

Results
Living in a rural environment and financial hardship were associated with greater reporting of independent and dependent life events. Sex differences were evident in the aetiology of life events and depression symptoms. Independent and dependent life events, but not depression symptoms, were heritable in males. Independent life events and depression symptoms, but not dependent life events, were heritable in females. Non-shared environmental influences explained phenotypic associations between independent life events and depression symptoms in both males and females. Genetic and non-shared environmental influences explained the phenotypic associations between dependent life events and depression symptoms in males. Only non-shared environment explained the covariation between dependent life events and depression symptoms in females.

Conclusions
Socio-demographic correlates of independent and dependent life events were similar to those reported in Western populations. Life events were associated with increased depression symptoms. Contrary to research in Western populations, we found that non-shared environmental, rather than genetic, influences explained much of the covariation between life events and depression symptoms. This suggests that whilst independent LEs may be heritable, the relationship is unlikely to be confounded by genetic influences and has significant implications for possible interventions for depression.

Website:

The relationship between independent and dependent life events and depression symptoms in Sri Lanka: a twin and singleton study | Social Psychiatry and Psychiatric Epidemiology (springer.com)

PDF:

https://link.springer.com/content/pdf/10.1007/s00127-019-01765-z.pdf