Researchers identified genes related to tendency to social isolation, depression and obesity

Researchers from the UK have identified genes that are related to a tendency to loneliness and social isolation, and have associations with depression or obesity

depression and obesity data

Studies have shown that social isolation is dangerous to health, even compared to risk factors such as smoking or lack of physical activity. 

Social isolation is known to be associated with psychological disorders, including depression, stress, cognitive deficits, memory loss, and impaired concentration. 

The impact of social isolation

Preliminary results from an ongoing study also suggest that social isolation might have a negative impact on the brain itself. 

Researchers from the University of Philadelphia and University of Pittsburgh placed mice, who were born and raised in an enriched social environments, in conditions of social isolation. 

After 30 days of isolation, the researchers examined the shape, size, and the branching structure of neurons in specific regions of the brain known to be associated with psychological effects induced by social isolation, such as alterations in memory, loss of sensory threshold and deficits in motor function. 

They found significant differences in the total neuronal volume across the specified brain regions.

Perceptions of loneliness 

But loneliness can have many reasons, and a new research shows that not all of them are dependent on the environment: genes also affect our chances of being lonely.

Researchers from the University of Cambridge, obtained from the UK Biobank, data about half a million of volunteers, including their medical data and DNA sequence. 

Among other things, volunteers were asked questions about loneliness, such as "do you feel lonely often?" "how many people live in your house?" And "how often do you visit friends or relatives, or do they visit you?"

The researchers found 15 genes that one of their versions (alleles), found only in part of the population, was probably related to loneliness. 

This does not mean that if a person has these alleles in all 15 genes he or she will be definitely lonely - there are many non-genetic factors that affect loneliness. But these genes may affect, to a certain extent, the chances of individual perception of loneliness. 

Some of the gene alleles responsible for feelings of loneliness tend to be associated with psychological and physical conditions such as neuroticism and depression, as well as obesity; obese people tended to be more socially isolated. 

Social behavior

The researchers examined additional data collected from Biobank volunteers, data concerning their participation in various social activities, such as regular visits to a gym or pub or attending a religious group, which may alleviate loneliness. 

They identified 38 genes associated with such activities, some specific for a given activity. A gene known to be related to alcohol consumption, for example, is not surprisingly associated with pub entertainment, rather than gym training.

To conclude, the study did not find genes responsible for loneliness or genes for social activity because there are none: these traits, like many other features, are very complex and influenced by a variety of factors, both environmental and genetic. 

However, the study suggests that certain genes may affect our level of loneliness, and even more so our perception and feeling of loneliness. It also points to a connection between genetic tendency to loneliness to other traits.