They believed in God in their youth - and now feel lonely: surprising findings of a study

That's the conclusion reached by researchers from the University of North Carolina at Charlotte, in collaboration with Harvard University's Human Thriving Programme.

The new study, published in the journal Stress and Health, is based on data from the large-scale National Adolescent to Adult Transition Study (Add Health). Participants were 10,529 people tracked from 1994 to 2008.

It is already known that involvement in religious or spiritual practices is often correlated with better well-being and lower stress levels. However, the role of specifically deeply personal, transformative experiences in adolescence has long remained understudied.

Researchers have focused on adolescents who had such experiences between the ages of 15 and 18. They accounted for about 17 per cent of the total number of participants. This group was more likely to have experienced financial difficulties in the family, strained relationships with parents, lower academic achievement and higher levels of depression as children.

Despite vulnerability in adolescence, by early adulthood (around age 25), these participants showed an increased propensity to volunteer and participate in elections compared to those who had no such experiences. At the same time, according to the authors, religious experiences appeared to foster a sense of meaning and a desire to do good in the community.

However, the opposite effect was also observed: young adults who had transformative spiritual experiences in their youth were more likely to report feelings of loneliness. Less robust but still notable associations were also found with signs of post-traumatic stress disorder (PTSD), lower self-rated health, symptoms of depression, functional limitations, and increased risk of diabetes and prescription drug abuse.

Even after accounting for a number of social and behavioural factors, key links between adolescent religious experiences and adult volunteering, voting and loneliness persisted.

The authors of the study conclude that such transformative experiences are a double-edged sword: they can either be a resource for active citizenship or leave a residue of psychological vulnerability.

The scientists emphasise the importance of further research into the processes of making sense of such experiences and their integration into the personality.