Evidence map›Paper›PMID 41924884›Full record

SynthesisActa psychiatrica Scandinavica2026

Pineal Gland Volume, Sleep Quality, and Psychiatric Disorders: A Systematic Review and Meta-Analysis.

Sophie Bolwig, Kristian H R Jensen

Abstract readSystematic ReviewMeta-Analysis
In one paragraph

Synthesis in Acta psychiatrica Scandinavica, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

2 authors.

Sophie BolwigNeurobiology Research Unit, Rigshospitalet, Copenhagen, Denmark.
Kristian H R JensenNeurobiology Research Unit, Rigshospitalet, Copenhagen, Denmark.ORCID https://orcid.org/0000-0001-6117-4379

Funding

Danmarks Frie Forskningsfond 4309-00083 ALundbeck Foundation R279-2018-1145
6 · The paper itself

Abstract

introductionDisturbances in sleep and circadian rhythms are features of several psychiatric disorders. The pineal gland regulates these rhythms via melatonin, with pineal gland volume (PGV) serving as a structural proxy. We conducted a meta-analysis to synthesize evidence on differences in PGV between patients with psychiatric disorders and healthy controls and the association between PGV and sleep outcomes.

methodSystematic searches of PubMed, Embase, Scopus, and Web of Science were performed (August 2025). Study quality was assessed using the Newcastle-Ottawa Scale. Random-effects meta-analyses using restricted maximum likelihood (REML) estimation were conducted for correlation and group-comparison outcomes. Subgroup analyses were performed by diagnostic category.

resultsFourteen studies compared PGV between psychiatric patients and healthy controls, and seven studies examined associations between PGV and sleep outcomes. PGV was significantly lower in patients with psychiatric disorders compared with healthy controls (1055 patients, 712 controls, Hedges' g = -0.54 [-0.68, -0.41], p < 0.001). Reductions were most pronounced in schizophrenia spectrum disorders (g = -0.63 [-0.81, -0.46], p < 0.001), and were approximately twice the magnitude observed in mood disorders (g = -0.33 [-0.59, -0.06], p = 0.027). The pooled association between larger PGV and better sleep was weak and nonsignificant (47 patients, 713 controls, Z

conclusionAcross psychiatric disorders, PGV is reduced relative to healthy controls, with the largest and most consistent reductions observed in schizophrenia spectrum disorders. In contrast, evidence for an association between PGV and sleep outcomes remains inconclusive. These findings suggest that reduced PGV may represent a trait-like structural alteration linked to psychiatric illness, particularly schizophrenia spectrum disorders, rather than a direct marker of sleep disturbance.

trial registrationPROSPERO: CRD420251138624.

Indexed as

Mental DisordersPineal GlandSleep QualitySleep Wake DisordersHumansmagnetic resonance imagingmood disorderspineal glandschizophreniasleep

Identifiers

PMID41924884
PMCPMC13242971

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.