The Effects of Ketamine on Cognition in Unipolar and Bipolar Depression
Bibliographic record
Abstract
To determine the objective neurocognitive effects of (1) single-dose ketamine, (2) repeated-dose ketamine, (3) ketamine adjunct to electroconvulsive therapy (ECT), and (4) ketamine as the anesthetic for ECT in major depressive disorder (MDD) and depression in bipolar disorder (BD). and their synonyms. Clinical trial registries (search date May 4, 2020) and reference sections of included articles were also searched. There was no restriction on language or year of publication. Of 4,035 identified articles, 17 met inclusion criteria. Controlled and open-label studies of adults who received at least 1 ketamine treatment for a current major depressive episode, as part of MDD or BD, were included. Only studies measuring cognition using at least 1 validated, objective neurocognitive assessment were eligible. Results are presented using a narrative review format. Data regarding change in cognitive performance from baseline to end-of-treatment and/or differences in cognition between ketamine and control groups were extracted. There were no negative effects of single- or repeated-dose intravenous ketamine up to 2 weeks post-treatment in MDD. Limited data were available for BD populations, as well as on other routes of ketamine administration. Data to definitively answer the question of whether ketamine has substantive or persistent cognitive effects are insufficient; thus, larger controlled trials measuring cognition as the primary outcome are needed. Future research should focus on different routes of ketamine administration, ketamine enantiomers, and BD populations.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.012 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.002 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".