The probability of developing a depression before you turn thirty is associated with genetics, but also has to do with the psychiatric history and socioeconomic status of a person’s parents. This is shown by a research result from iPSYCH, which may help to improve identifying the risk of depression.

2021.01.27 | Helle Horskjær Hansen

The fact that people who are genetically disposed are diagnosed with depression is no secret. Previous research has shown this (link to article). It is also known that depression is a common but very serious condition which is very costly for both the individual and society as a whole. In Denmark, 15.5 per cent of woman and nine per cent of men receive treatment for depression at a psychiatric hospital at some stage of their lives.

A result from the Danish psychiatry project iPSYCH now shows that the genetic predisposition cannot stand alone. The risk of depression is also increased by other known risk factors such as family history and economic status.

"In many ways, genetics are exactly like all other risk factors – a high genetic risk score isn’t necessarily the end of the world, it just increases the risk," says one of the researchers behind the study, Esben Agerbo from iPSYCH.

The purpose of the study was to assess the individual's genetic disposition or risk score for early-onset depression in combination with the parents' psychiatric history and socioeconomic status – with the socioeconomic status being measured by factors such as e.g. the mother's level of education and marital status and the father's employment.

Pronounced in women

In total, the researchers analysed data from 17,098 people with a depression and 18,582 without.

"We saw a significant correlation between the genetic risk score, the parents' medical history and lower socioeconomic status and the risk of depression, particularly in women," says the researcher.

For example, the study demonstrated that 24 per cent of women aged 30 years with a high genetic risk score and a mother or father with a psychiatric disorder were diagnosed with depression. The corresponding risk for women with low genetic risk and without parental history is three per cent. 

The results suggest that, while the genetic risk score alone does not identify the risk of depression better than known risk factors, it can contribute significantly in combination with these known major risk factors. 

The results have been published in the recognised scientific journal JAMA Psychiatry.

Esben Agerbo emphasises that it is also important to study the age-related risk of depression and not just the risk factors, as previous studies have done.

Background for the results

• A cohort study.
• Financed by the Lundbeck Foundation.
• Professor Naomi R. Wray, Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland, Australia.
• Professor John McGrath, Queensland Brain Institute, University of Queensland, St Lucia, Queensland, Australia. 23andMe Inc. The Psychiatric Genomics Consortium.
• Read the scientific article here

Contact

Esben Agerbo
Aarhus University, Department of Economics and Business Economics
ea@econ.au.dk
(+45) 5177 9359