Will lockdown loneliness make us loners?

Reduced social preference in isolated zebrafish is caused by stress and anxiety, not observed anti-social patterns

June 10, 2020

Science Daily/Sainsbury Wellcome Centre

Loneliness affects both mental and physical health, but counterintuitively it can also result in a decreased desire for social interaction. To understand the mechanics of this paradox, researchers investigated social behavior in zebrafish.

Over the past few months at least half of the world's population has been affected by some form of lockdown due to COVID-19, and many of us are experiencing the impact of social isolation. Loneliness affects both mental and physical health, but counterintuitively it can also result in a decreased desire for social interaction. To understand the mechanics of this paradox, UCL researchers based at the Wolfson Institute and the Sainsbury Wellcome Centre investigated social behaviour in zebrafish. Their results are published in eLife.

Most zebrafish demonstrate pro-social behaviour, but approximately 10% are 'loner' fish who are averse to social cues and demonstrate different brain activity than their pro-social siblings. However, even typically social zebrafish avoid social interaction after a period of isolation. PhD students Hande Tunbak and Mireya Vazquez-Prada, Postdoctoral Research Fellow Thomas Ryan, Dr Adam Kampff and Sir Henry Dale Wellcome Fellow Elena Dreosti set out to test whether the brain activity of isolated zebrafish mimics that of loner fish or whether other forces were at play.

To investigate the effects of isolation, the researchers isolated typically social zebrafish from other fish for a period of two days and then compared their brain activity to zebrafish who demonstrated aversion to social interaction without having been isolated. The isolated fish demonstrated sensitivity to stimuli and had increased activity in brain regions related to stress and anxiety. These effects of isolation were quickly overcome when the fish received a drug that reduces anxiety.

The differences between loner fish and their siblings were found mostly in the hypothalamus, the region of the brain responsible for social rewards. The loner fish hypothalamus did not demonstrate the same pattern of activation during social exposure as its typical counterparts, indicating that loner fish do not experience rewards in the same way as typical fish during social interactions.

By contrast, 'lonely' fish -- those that demonstrated typical social behaviour and were isolated -- demonstrated hypersensitivity to stimuli and activation of brain regions associated with stress and anxiety. Lonely fish experienced actively negative outcomes from social interaction whereas loner fish simply did not experience reward.

"A detailed view of the zebrafish brain can provide important clues for all of us currently experiencing the effects of social isolation," says Dr Elena Dreosti. Our understanding of the neural mechanisms of social behaviour are limited, but we do know that zebrafish and humans share a fundamental drive for social interaction that is controlled by similar brain structures. Although human behaviour is much more complex, understanding how this basic social drive arises -- and how it is affected by isolation -- is a necessary step towards understanding the impact of the social environment on human brains and behaviour. The zebrafish, which is completely transparent throughout early development, offers neuroscientists a detailed view of its brain circuitry.

We won't all be loners after lockdown, but we will be anxious upon returning to our normal social lives. As we emerge from lockdown, we should be aware of this new sensitivity and anxiety, but recognise that overcoming it is necessary for returning to a normal, healthy, social existence.

https://www.sciencedaily.com/releases/2020/06/200610112057.htm

Feeling depressed? Mahjong might be the answer

Study shows that for older Chinese, it might boost mental health

September 17, 2019

Science Daily/University of Georgia

When it comes to boosting mental health among older Chinese, it might be as simple as a game of mahjong, according to a new study from the University of Georgia.

Regularly playing the popular tile-based strategy game was one of several types of social participation linked to reduced rates of depression among middle-aged and older adults in China in the study appearing in Social Science & Medicine.

"Global economic and epidemiologic trends have led to significant increases in the burden of mental health among older adults, especially in the low- and middle-income countries," said Adam Chen, an associate professor of health policy and management at UGA's College of Public Health and study co-author.

Poor mental health is a major issue in China, which accounts for 17% of the global disease burden of mental disorders. On top of that, mental health issues related to social isolation and loneliness are on the rise as China's number of older adults -- as in other nations -- continues to increase.

The benefits of participating in social activities to mental health have been widely acknowledged, and some work has been done in developed nations, including the U.S. and Japan, to better understand this relationship.

But little is known about the role of social interaction and mental health outside of these settings.

"Social participation manifests itself in different formats within different cultural contexts," said Chen.

"Our paper provides evidence on the association between social participation and mental health in the context of a developing country. We also examined the rural-urban difference, which has not been examined extensively in this line of literature."

Chen and collaborators from China's Huazhong University of Science and Technology analyzed survey data from nearly 11,000 residents aged 45 years and older from the nationally representative China Health and Retirement Longitudinal Study.

They looked at symptoms of depression and compared it to the type and frequency of social participation, including visiting with friends, playing mahjong, participating in a sport or social club, and volunteering in the community.

They found that, on the whole, participating in a wide variety of activities more frequently was associated with better mental health. Specifically, urban residents who played mahjong, a popular strategy game, were less likely to feel depressed.

That wasn't too surprising for Chen, as this finding was in line with other studies, but he was surprised to find that rural Chinese overall tended to report poor mental health compared to their urban counterparts.

"Traditionally, rural China featured tight-knit communities of close kinship, often with a limited number of extended large families in a village," he said. "We were expecting strong ties and communal bonds in rural China, but it appears that we were wrong."

Chen suspects that the social structures in rural China were disrupted as many able-bodied adults moved into cities to find work. While family ties remained strong, community ties weakened in rural areas.

"What is more surprising is that mahjong playing does not associate with better mental health among rural elderly respondents," added Chen. "One hypothesis is that mahjong playing tends to be more competitive and at times become a means of gambling in rural China."

The authors believe these findings may offer a guide to health practitioners designing policies and interventions to improve mental health among older Chinese.

The findings could also translate, said Chen, to Asian American communities.

"Older Asian Americans have a much higher proportion of suicidal thoughts than whites and African Americans," he said. "Improving social participation among older Asian Americans may help to address this burden to the U.S. population health that has not received due attention."

https://www.sciencedaily.com/releases/2019/09/190917115420.htm