Spouses often have overlapping mental disorders
A new large-scale study of more than 14 million people in different countries has found: married couples are more likely than might be expected to suffer from the same mental health problems.
This similarity has been observed for 90 years and is confirmed in different cultures.
An international team of scientists published a paper in the journal Nature Human Behaviour. They analysed correlations between spouses for nine psychiatric diagnoses, including schizophrenia, depression, bipolar disorder, ADHD, eating disorders and others.
The sample included:
5 million couples from Taiwan
571,534 couples from Denmark
707,263 couples from Sweden
A total of 14.8 million people. Up to 6 million couple controls were also used. Main findings:
In all countries there was a positive correlation between spouses with the same disorder.
In Taiwan, similarities between spouses for all nine diagnoses were confirmed except for anorexia, OCD and bipolar disorder, where regional differences were noted.
Parents with the same diagnoses have an increased risk of transmitting the disorder to their children - especially for schizophrenia, depression, bipolar and alcohol use disorder.
These trends are supported by genetic data, including GWAS (genome-wide association studies).
The study also found that:
The overlap of addiction-related disorders between spouses increased over time.
In contrast, OCD became less common in both partners in the couple.
The level of overlap for ADHD fluctuated but did not show a consistent trend.
The level of concordance on depression and addictions between parents and children increased with new generations.
Previously, it had been assumed that mental disorders were influenced by genetics and environment. But the study emphasises another factor - non-random m ate choice (assortative mating). People tend to choose life partners with a similar mental profile, which increases the likelihood of passing the disorder on to their children.