Two studies in Poland show that whole body cryotherapy can help in treating anxiety and depression.
1. One study found improvement on 11 of 14 items on an anxiety scale and improvement on 12 of 16 items on a depression scale.
2. Another study showed a decrease of at least 50% in depressive symptoms among 34.6% of the treatment group and a decrease of at least 50% in anxiety symptoms among 46.2% of the treatment group.
Can short-term exposure to extremely low temperatures be used as an adjuvant therapy in the treatment of affective and anxiety disorders? (Link)
Whole-body cryotherapy as adjunct treatment of depressive and anxiety disorders. (Link)