People with more severe anxiety, depression, or social difficulties initially improved in well-being during low-intensity mindfulness interventions (three or eight sessions), but those with worse symptoms tended not to sustain improvements and rebounded toward baseline during follow-up. The findings suggest that such brief mindfulness-based treatments can still be clinically useful for individuals with more severe mental health symptoms, as they experienced initial improvement, but offering longer-duration treatment might prevent symptom rebounding.
A systematic review and meta-analysis of 26 randomized clinical trials with 1,166 patients experiencing a major depressive episode found that intravenous ketamine infusions significantly reduce suicidal and depressive symptoms in the acute phase. A single ketamine infusion lowered suicidal symptoms at 24 hours and at 1 month, and repeated infusions produced similar reductions. Depressive symptoms decreased significantly from 4 hours through 1 week after a single infusion and after repeated infusions. Serious adverse events were unrelated to the interventions, and other side effects were transient. Longer-term outcomes remain unclear.