Ketamine rapidly and lastingly reduces depression in people with treatment-resistant depression (TRD), but how it works remains unclear. TRD is linked to inflammation, and ketamine may curb inflammatory processes. Whole blood gene expression was compared between 21 healthy controls and 26 TRD patients, and again in TRD patients 24 hours after a single ketamine infusion. Before treatment, TRD patients showed activation of interferon signaling pathways. Among TRD patients, those who later responded to ketamine had higher levels of two glutamate receptor genes (GRM2 and GRIN2D) before the infusion. Ketamine response produced a distinct gene expression signature, but no evidence of anti-inflammatory changes was found. More research is needed on the peripheral immune system's role.
Mind-body exercises such as yoga and mindfulness significantly reduce PTSD symptoms, depression, and anxiety in people with PTSD. A meta-analysis of 16 randomized controlled trials found a moderate effect on PTSD symptoms (standard mean difference = -0.41), depression (-0.35), and anxiety (-0.31). The most effective regimen for PTSD symptoms in patients under 45 was 60-150 minutes of mindfulness per session for 8-16 weeks. For depression, 150-180 minutes of yoga once weekly was effective. The optimal type, frequency, and duration for anxiety could not be determined due to limited trials. Mind-body exercises are recommended as an adjunct treatment, but more rigorous trials are needed.