Kan bastu faktiskt förbättra din psykiska hälsa? Här är vad forskningen säger

Mental health has become one of the defining concerns of the twenty-first century. Rates of anxiety and depression have risen steadily across the developed world. The tools available to people struggling with these conditions — therapy, medication, lifestyle change — are genuinely helpful, but they are not universally accessible, not always sufficient, and not without side effects.

Against this backdrop, research on the mental health effects of sauna bathing has attracted serious scientific attention. The findings are encouraging — not as a replacement for professional care, but as a meaningful complementary practice with real neurobiological effects.

What Happens to the Brain in a Sauna

The immediate neurological effects of sauna exposure are well characterised.

Beta-endorphin release. Heat stress triggers the release of beta-endorphins — the same neurotransmitters released during intense exercise and responsible for the sense of wellbeing often described as a "runner's high." This is not a metaphor or a placebo effect; it is a measurable biochemical response.

Norepinephrine increase. Sauna heat produces a modest increase in norepinephrine — a neurotransmitter that plays a role in attention, focus, and mood regulation. This is part of why many sauna users report feeling sharper and more energised after a session.

Cortisol reduction. Cortisol — the body's primary stress hormone — rises initially in response to the heat stress of sauna. But in regular sauna users, post-session cortisol levels are significantly lower than baseline. The body's stress regulation system adapts, becoming more efficient. Regular sauna users show better cortisol regulation across the day, not just during sessions.

Heat shock proteins. Repeated heat exposure induces the production of heat shock proteins (HSPs), which play a role in cellular repair and may protect against neurological damage associated with chronic stress.

The Depression Research

A 2018 population study published in Psychiatry Research analysed data from over 2,000 Finns and found a statistically significant inverse relationship between sauna use frequency and depression: people who used sauna four or more times per week were substantially less likely to report depressive symptoms than those who used it once a week or less.

This is a correlation study — it cannot prove that sauna causes lower rates of depression. People who use sauna more often may also be more socially connected, more physically active, and more health-conscious in general. But the association is consistent with the known neurobiological mechanisms, and it persists even after adjusting for confounding variables.

More directly relevant is a 2023 pilot study from the University of Wisconsin-Madison, which put clinically depressed patients through eight weeks of regular sauna sessions. Participants showed significant reductions in depression scores compared to controls. The researchers proposed that the mechanism was partly neurobiological (endorphin and norepinephrine effects) and partly social (the structured, communal nature of the sauna sessions provided a form of behavioural activation).