We know that social isolation, involuntary confinement, and poverty tend to be extremely detrimental to health.

However, many humans have willingly isolated themselves and taken vows of poverty for religious and spiritual reasons for thousands of years.

Do we know if these people often face the same consequences? Are they affected differently from people who don’t have a choice?

No sources. Violating rule 9.

I have a feeling this has probably been studied, but I'm not a sociologist so I wouldn't know where to look.

https://scienceinsights.org/why-do-people-become-hermits-causes-and-psychology/

Voluntary hermits: While solitude can be challenging, it is often accompanied by structured routines, spiritual guidance, and community support, which can mitigate negative effects. Some traditions emphasize that solitude without moral living can lead to despair or madness, underscoring the need for discipline Academia.edu.

Prisoners in solitary: Research shows severe psychological and physical impacts, including insomnia, paranoia, hallucinations, aggression, and long-term mental health deterioration Wikipedia+1. The lack of control, constant surveillance, and punitive atmosphere can erode self-worth and increase risk of self-harm or suicide.

From the interwebs, not my research