Loneliness Linked to 37% Increase in Parkinson’s Disease Risk

Earlier this week, a study published in JAMA Neurology linked reports of loneliness to an elevated risk of Parkinson’s disease, indicating that social connection or loneliness is a psychosocial determinant of health.

The study used data from the United Kingdom Biobank to gather information on participants 38–73 who were initially assessed between March 13, 2006, and October 1, 2010. Using that data, the researchers identified 491,603 participants with loneliness data who did not have a PD diagnosis upon initial assessment. Each patient had a follow-up on October 9, 2021.

Loneliness was measured based on participants’ responses to the following question: Do you often feel lonely? Patients who responded “no” got a score of zero, while those who responded “yes” got a score of one.

Meanwhile, PD incidence was determined using data from the National Health Service (NHS) hospital admission data and death records. “Most incident cases were determined as the earliest known relevant International Classification of Diseases, Ninth Revision code 3320 or International Statistical Classification of Diseases and Related Health Problems, Tenth Revision code G20 in the hospital admission records,” noted researchers in the article.

Of all the participants included in this cohort study, approximately 2,822 developed PD after a 15-year follow-up.

Overall, the researchers found that those who reported being lonely had a 37% greater risk of developing Parkinson’s disease. After adjusting for demographic factors, including socioeconomic status, social isolation, PD polygenetic risk score, smoking, physical activity levels, BMI, and comorbidities like diabetes, hypertension, stroke, myocardial infarction, and depression, researchers found that reported loneliness still correlated with a 25% increased risk of PD.

“This large cohort study found that loneliness was associated with risk of incident PD across demographic groups and independent of depression and other prominent risk factors and genetic risk. The findings add to the evidence that loneliness is a substantial psychosocial determinant of health,” concluded researchers in the study.

This evidence underscores claims made by the United States Surgeon General, Vivek H. Murthy, MD, MBA, earlier this year in an advisory issued by the United States Department of Health and Human Services (HHS). The advisory emphasized that social connection should be a public health priority, revealing that loneliness was associated with a 26% greater risk for premature death.

As more insight into the impacts of isolation and loneliness is revealed, it is critical to prioritize social connection.