The effects of experimentally lowered serotonin function on emotional information processing and memory in remitted depressed patients
Bibliographic record
Abstract
It has been well documented that acute tryptophan depletion (ATD) induces symptoms in remitted depressed patients treated with an SSRI. ATD also has effects on cognition, both in patients and in healthy samples. The exact nature of ATD-induced cognitive changes in depression remains unclear. It is also unclear whether cognitive effects can be induced through partial ('low-dose') depletion. The aim of this study is to investigate the differential effects of low-dose and high-dose ATD on emotional information processing and mood in remitted depressed patients. Eighteen remitted depressed patients received high-dose and low-dose ATD in a randomized, double-blind, within-subjects crossover design. Mood was assessed before and after administration of the depletion drink. Five hours after administration, patients conducted tests measuring neutral and emotional information processing. High-dose ATD increased depressive symptoms and induced a temporary depressive 'relapse' in half of the patients. High-dose ATD also decreased the recognition of fear and impaired learning and memory retrieval. The impaired learning occurred only in mood-responders. Low-dose ATD had no effects on mood but speeded the recognition of facial expressions of disgust. Accurate recognition of sad faces at baseline was associated with mood response to ATD. High-dose ATD leads to changes in memory and in the recognition of negative facial expressions in SSRI-treated remitted depressed patients. The effect of low-dose ATD on mood and cognition seems to be quite limited. Emotional information processing at baseline predicts mood-response to ATD.
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".