Source: MILA
Canada CIFAR AI Chair Danilo Bzdok, researcher at the Neuro and Mila – Quebec AI Institute, and colleagues uncovered brain substrates underlying insufficient regular social support with peers that have potential implications for loneliness, substance misuse, and resilience to stress. These findings from 40,000 participants, recruited across the United Kingdom, are extending the researchers’ previous study revealing that a neural “signature” may reflect how we respond to feelings of social isolation.

With social distancing and work-from-home measures due to the COVID-19 pandemic, many individuals have experienced reduced social connections that ultimately impact their quality of life, as loneliness has been shown to impose significant risks to physical, mental and brain health. Regular social contact and the sharing of life experiences within one’s social circle have been shown to be key to our well-being. Now, a new population-scale imaging-genetics study has systematically assessed the effects of social embeddedness and friendships on the brain successfully identified neural substrates that delineate rich versus poor social support.

To this end, Dr. Bzdok, who is an Associate Professor in the Department of Biomedical Engineering at McGill University, led an international team, including, among others, researchers from Oxford University (UK), University of Vienna (Austria), University of Miami (USA), as well as the Donders Institute (Netherlands). They applied advanced pattern-learning algorithms to high-resolution magnetic resonance imaging (MRI) brain scanning, genome-wide variants and a wide array of psychological self-assessments of approximately 40,000 men and women aged 40-69 years who volunteered their information to the UK Biobank, an open-access database available to health scientists worldwide. The MRI data obtained was used to compare participants who reported confiding in someone within their close network daily with those who did not.

Bzdok and colleagues found distinctive brain regions centering on the salience network—a set of brain regions involved in human communication, social behaviour, and self-awareness—that correlate to the level of social support a person regularly experiences. Additionally, the researchers identified reliable structural and functional associations of regular social support from close others within the limbic system. Their findings show that individuals with regular and consistent social support exhibited increased inter-network connectivity in the salience and limbic networks, which can be associated with enhanced functional coupling of these brain systems.

“The identified neural circuits, underlying the studied social isolation, are closely linked to substance-use behavior, loneliness and stress resilience,” explained Dr. Bzdok. “This insight could help identify new avenues for prevention and opportunities for medical intervention in the future.”

The demographic data obtained from men and women over the age of 40 also revealed brain manifestations of high versus low social support which were robustly linked to emotional tension and health- and substance-use-related factors, including difficulty getting up in the morning, as well as alcohol consumption, smoking abuse, and low-stress buffer capacity. In times of uncertainty as the world continues to face the ongoing pandemic, the present study extends previous research which suggests that social connectedness reduces general levels of psychological distress and anxiety.

Reinforcing and extending the investigators’ previous neuroscience research which explored subjective reports of loneliness, their work highlights the critical need to recognize that loneliness is on the rise and a major public health problem that must be addressed in today’s society. The absence of social experiences and their effects on mental health further emphasizes the urgent need to reduce loneliness in today’s society. According to Dr. Bzdok, a “deepened understanding of the consequences of social isolation for mental and physical health will be key in the years after the COVID-19 pandemic.”

The study was published in the journal Cerebral Cortex on May 13, 2021. This research was funded by Brain Canada, the Healthy Lives Healthy Brains Initiative, the Canadian Institutes of Health Research, US National Institutes of Mental Health, Google, and Canada CIFAR AI chairs program. No disclosures.

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