Journal of Psychosocial Nursing and Mental Health Services
June 30, 2016
Robert H Howland
22 citations
Antidepressant, atypical antipsychotic, and hallucinogen drugs act partly through the serotonin-2A (5HT2A) receptor. Hallucinogens like psilocybin bind as agonists at this receptor, altering perception, mood, and cognition. Some hallucinogens are being tested in small Phase 2 studies for depression, alcoholism, smoking cessation, anxiety, and PTSD. However, concurrent use of antidepressants or atypical antipsychotics may attenuate hallucinogens' therapeutic effects because those medications desensitize or down-regulate 5HT2A receptors. This finding has implications for optimizing hallucinogen therapy in psychiatry.
The British journal of psychiatry : the journal of mental science
May 13, 2025
Shabnam Hossein, Manivel Rengasamy, Aiyedun Uzamere et al.
3 citations
Ketamine infusion most strongly alleviates sadness both immediately and during the first week after treatment, whereas improvements in suicidal thoughts emerge only after three to four weeks. In a secondary analysis of 152 adults with treatment-resistant depression (38.8% with suicidal ideation at baseline), those randomized to a single 40-minute intravenous infusion of ketamine (0.5 mg/kg) showed greater early improvement in sadness-related symptoms compared with saline. Network analyses revealed that ketamine increased connectivity among depressive symptoms, strengthening interrelationships between residual symptoms. The findings suggest that different depressive symptoms respond to ketamine with distinct time courses and possibly different mechanisms.
Brain, behavior, and immunity
April 4, 2025
Manivel Rengasamy, Benjamin Panny, Zakary Hutchinson et al.
3 citations
In adults with treatment-resistant depression, a single ketamine infusion did not produce detectable changes in blood markers of neurotrophic and inflammatory factors compared with a saline placebo, nor were those markers linked to depression improvement over five days. Among 133 participants, only one subgroup—those with a body-mass index below 25—showed an association: rising levels of interleukin-1 receptor antagonist in the first day after ketamine correlated with less reduction in depression symptoms. The results do not support the idea that peripheral neurotrophic or inflammatory factors mediate ketamine's rapid antidepressant effects, though central nervous system activity may still be involved.
Journal of Psychopathology and Clinical Science
April 1, 2025
Shabnam Hossein, Mary L Woody, Benjamin Panny et al.
3 citations
Ketamine rapidly improves symptoms of treatment-resistant depression (TRD), but because TRD varies widely among patients, markers are needed to personalize treatment. This study measured brain functional connectivity during positive mood processing in 152 adults with TRD before they received either ketamine or a saline placebo. Two connectivity-based subgroups emerged: Subgroup A (110 patients) and Subgroup B (42 patients). Ketamine improved depression uniformly across both subgroups. However, among patients given saline, those in Subgroup B were more likely to show a placebo response 24 hours later than those in Subgroup A. Thus, brain connectivity patterns predicted placebo response but not ketamine response.
Molecular Psychiatry
November 1, 2024
H Nur Eken, Crystal Spotts, Benjamin Panny et al.
1 citation
A combination of ketamine infusion and a digital training program called automated self-association training (ASAT) produced more positive implicit self-associations immediately after treatment in adults with treatment-resistant depression, compared to control groups that received only one active component. These changes in implicit self-worth tracked with concurrent depression symptom improvement across all groups and specifically predicted longer-term depression relief at 30 days for the combined treatment group. The findings indicate that shifting implicit self-esteem during a post-ketamine 'plasticity window' is a key mechanism behind the combined treatment's antidepressant effect, confirming the intended cognitive target.