Repeated intravenous infusions of ketamine: Neurocognition in patients with anxious and nonanxious treatment-resistant depression

Neurocognitive performance of repeated versus single intravenous subanesthetic ketamine in treatment resistant depression

“…Improvement in similar cognitive dimensions was reported by studies of repeated ketamine (e.g., speed of processing 32,34,37 and visual memory and executive function 36 ) and single ketamine (e.g., attention 33 and working and visuospatial memory 35 ). The prefrontal cortex has been intricately linked to executive functions including attention, working memory and speed of processing 38 .…”

“…In our post-hoc analysis of the six ketamine, better performance in working memory (visual and complex), and lower attention at baseline were associated with greater antidepressant response. Previously, two open label studies of six ketamine also reported attention and working memory as predictors of response among Veterans 12 and non-anxious Chinese with TRD 32 , respectively. Other studies, however, revealed a lack of association between depression response and baseline cognition .…”

Ketamine as an antidepressant: overview of its mechanisms of action and potential predictive biomarkers

“…166,167 Only the group of anxious depressed patients demonstrated a similar change in the third study. 168 Improvement in many domains of memory in another study of repeated infusions over 12 days with a 4 week follow-up period was seen, but was not significant when controlling for depressive symptom improvement. 169 A single infusion of 0.5 mg/kg in TRD patients was also seen to be slightly beneficial in attention and response control as well.…”

“…170 In terms of predictive cognitive variables of response to ketamine, greater baseline visual learning predicted degree of MDD response to ketamine treatment in two of the above studies. 166,168 Low attention 169 and processing speed have also been seen to be predictive. 171…”

“…Ketamine treatment in actual MDD treatment protocols also shows promising results in CCS. Three groups of patients – with treatment-resistant unipolar and bipolar depression, 166 TRD 167 and anxious/non-anxious depression 168 – were given six ketamine infusions over 12 days, with similar cognitive testing in a 2 week follow-up period. No deterioration in cognitive function was seen in any of the studies.…”