Frontier mental health research: psychedelics & drug studies

Key findings

• Ketamine can reduce depression symptoms very fast, sometimes within hours, and effects often peak around 24 hours after a single infusion. ^{10152 10149 15070}
• The antidepressant effect after one ketamine infusion usually lasts days to about two weeks, so many studies use repeated doses to keep benefits going. ^{12152 10149}
• Esketamine (a nasal spray) is approved for treatment-resistant depression and for depression with acute suicidal thoughts, and it must be given in a clinic with two-hour monitoring and blood-pressure checks. ^{10144 12156 15070}
• A common research method is an intravenous infusion of about 0.5 mg per kg over roughly 40 minutes; studies also test other routes like intranasal, subcutaneous, or intramuscular dosing. ^{10149 10159 12156 12152}
• Beyond depression, ketamine has shown early signs of helping with suicidal thoughts, PTSD, anxiety disorders, and some substance-use problems, but the evidence outside depression is smaller or less certain. ^{12152 9521 15068}
• Common short-term side effects include dissociation (a strange or detached feeling), sedation, higher blood pressure, dizziness, and brief psychosis-like sensations; these usually go away within a few hours. ^{12152 10159 10151 12156}
• Studies done under medical supervision report only a few clear cases of tolerance or dependence, so the addiction risk in clinical use seems low, but researchers say long-term risk is still uncertain. ^{8828 12152 12365}
• Scientists have evidence about how ketamine works, such as blocking NMDA receptors and boosting AMPA signaling, BDNF, and mTOR pathways that support brain plasticity, but the exact chain of events is still being worked out. ^{10147 10146 10148 9521 15070}
• Many published ketamine studies are small or have risks of bias, so experts call for larger, longer trials to answer questions about long-term safety, optimal dosing plans, and which patients will benefit most. ^{12152 10153 15129}