Endpoint

Anxiety symptom severity (pooled across unnamed instruments)

CAT:outcome/anxiety-symptom-severity-pooledreported in standardised mean difference (SMD)3 findings from 3 compounds

What moved it

3 findings · 3 compounds · 1 null · by evidence strength

Compound	Direction	Findings	Strongest evidence
gabapentin	down	1	Evidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.
coenzyme Q10	no effect	1	Evidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.
melatonin	down	1	Evidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.

Reported to move it

2 findings

gabapentin — decreases
ModerateEvidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.Finding
“Compared with placebo, both pregabalin (SMD -0.55, 95% CI -0.92 to -0.18) and gabapentin (SMD -0.92, 95% CI -1.32 to -0.52) were significantly more effective in reducing preoperative anxiety.”
Quoted verbatim from Gabapentin and pregabalin in bipolar disorder, anxiety states, and insomnia: Systematic review, meta-analysis, and rationale..
Study

meta-analysis
Population

adult surgical patients with preoperative anxiety, pooled double-blind RCTs of gabapentin versus placebo
Effect -0.92 standardised mean difference, 95% CI -1.32 to -0.52
Gabapentin and pregabalin in bipolar disorder, anxiety states, and insomnia: Systematic review, meta-analysis, and rationale.2022PMID:34819636An author is affiliated with a producerPermalink
melatonin — decreases
Very limitedEvidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.Finding
“Compared with placebo, melatonin reduced the standardised mean difference (95% CI) pre-operative anxiety score by 0.88 (0.44-1.33) and postoperative pain score by 1.06 (0.23-1.88).”
Quoted verbatim from A systematic review of peri-operative melatonin..
Study

meta-analysis
Population

surgical patients undergoing peri-operative care, pooled across 24 RCTs (1794 participants)
Effect 0.88 standardised mean difference, 95% CI 0.44 to 1.33
A systematic review of peri-operative melatonin.2014PMID:24835540Permalink

Measured, no effect detected

1 finding

coenzyme Q10 — no detected effect on
Very limitedEvidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.FindingNull result
“Regarding anxiety severity, only two small studies were analyzed, and no statistically significant reduction was observed with CoQ10 (101 patients, -0.28 [-0.70, 0.13]).”
Quoted verbatim from The effect of coenzyme Q10 supplementation on depressive symptoms and anxiety: a systematic review and meta-analysis of randomized controlled trials..
Study

meta-analysis
Participants

101
Population

patients across clinical populations with anxiety symptoms
The effect of coenzyme Q10 supplementation on depressive symptoms and anxiety: a systematic review and meta-analysis of randomized controlled trials.2025PMID:40833470Permalink

How it is measured

Standardised mean difference in anxiety symptom severity pooled across whichever self-report or clinician-rated instruments the primary trials used, with no single instrument common to the analysis. The constituent instruments are listed with each finding.

Sources cited

3 papers

Subject: anxiety symptom severity (pooled across unnamed instruments)
Findings: 3
Papers: 3

Compound

Direction

Findings

Strongest evidence

gabapentin

down

coenzyme Q10

no effect

melatonin

down