Childhood Loneliness Linked to Faster Cognitive Decline and Higher Dementia Risk

According to a major new study published on November 17, 2025, the roots of cognitive decline later in life may begin in childhood. Researchers discovered that the subjective, emotional feeling of loneliness in childhood is strongly linked to accelerated cognitive decline and a significantly higher risk of dementia in people aged 50 and up.

The study found that people who felt lonely as children started their middle-aged years with lower memory and thinking skills. Moreover, their cognitive abilities declined at a faster pace each year compared to those who were not lonely as kids. In fact, the 4.2% of participants who reported frequent childhood loneliness faced the highest risk of cognitive decline.

Crucially, the link between childhood loneliness and dementia risk persisted even for those who were no longer lonely as adults, suggesting the damaging effects of early-life isolation can cast a long shadow over the brain's health. Adults who recalled a childhood marked by both loneliness and a lack of close friends faced a 41% greater risk of developing dementia, which affects an estimated 7 million Americans and is projected to grow to 14 million by 2060.