Single, Repeated, and Maintenance Ketamine Infusions for Treatment-Resistant Depression: A Randomized Controlled Trial

Encoding, Consolidation, and Renormalization in Depression: Synaptic Homeostasis, Plasticity, and Sleep Integrate Rapid Antidepressant Effects

“…In support of ENCORE-D, clinical evidence suggests that the most robust antidepressant responses to subanesthetic ketamine become evident during the following day (i.e., after one night's sleep) (Berman et al, 2000;Zarate et al, 2006a;Lapidus et al, 2014;Phillips et al, 2019). Studies have also demonstrated the normalization of global functional connectivity patterns when measured 24 hours after treatment (Abdallah et al, 2017a,b) and decreases in suicidal cognition within the same time frame (Price et al, 2014(Price et al, , 2009Wilkinson et al, 2018).…”

“…Indeed, Evans et al (2018) reported that the connectivity changes induced by ketamine in depressed patients were reversed after 10 days, in line with the duration of ketamine's antidepressant effects and in alignment with a viable timeframe for multiple cycles of renormalization to occur. Moreover, repeated ketamine infusions have cumulative effects in treating depression, and patients that relapse between treatments still respond to new infusions (Phillips et al, 2019). This suggests that such changes can be reestablished with further treatments.…”

Essential role of microglial transforming growth factor-β1 in antidepressant actions of (R)-ketamine and the novel antidepressant TGF-β1

“…In 2000, Berman et al 2 demonstrated the rapidacting and sustained antidepressant effects of the NMDAR antagonist ketamine in patients with major depressive disorder (MDD). Subsequently, several groups replicated the robust antidepressant effects of ketamine in treatment-resistant patients with either MDD or bipolar disorder [3][4][5][6][7][8][9][10] . Interestingly, ketamine rapidly reduced suicidal thoughts in depressed patients with suicidal ideation within 1 day and for up to 1 week 11,12 .…”

Ketamine for chronic depression: two cautionary tales

“…Unexpected data about the clinical course of ketamine trial participants were gathered during a psychotherapy pilot study we conducted immediately after our 3-phase clinical trial that examined the effects of adjunctive ketamine infusions for refractory depression. 6 Our preliminary study results were presented at the European Association of Cognitive Behavioural Therapy Annual Meeting in 2016. Two adverse events occurred that raise questions about the impact of receiving what is often perceived as a novel and end-ofthe-line treatment.…”