Evidence map›Paper›PMID 42286512›Full record

ArticleBMC psychiatry2026

Seasonal variation in ammonia among euthymic women with Bipolar I Disorder treated with valproic acid in Turkey: a prospective study.

Ipek Özönder Ünal, Habib Erensoy, Tonguc Demir Berkol

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Article in BMC psychiatry, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

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2 · The registry

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

3 authors.

Ipek Özönder ÜnalDepartment of Psychiatry, Kartal Dr Lutfi Kirdar City Hospital, D-100 Güney Yanyol, Cevizli, Cevizli Mevkii No:47, Kartal, Istanbul, 34865, Turkey. ipekozonder@gmail.com.ORCID http://orcid.org/0000-0003-3509-0061
Habib ErensoyDepartment of Psychiatry, Medical Faculty, Uskudar University, Istanbul, Turkey.ORCID http://orcid.org/0000-0002-4278-2739
Tonguc Demir BerkolDepartment of Psychiatry, Bakirkoy Research and Training Hospital for Psychiatry, Neurology and Neurosurgery, Istanbul, Turkey.ORCID http://orcid.org/0000-0003-4341-6826

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundValproic acid (VPA)-induced hyperammonemia (VPA-IH) is a common metabolic complication in Bipolar I Disorder (BD-I). Although VPA creates a state of metabolic vulnerability, the influence of seasonal environmental stressors on ammonia homeostasis remains unexplored.

methodsThis prospective longitudinal study followed 112 euthymic female patients with BD-I receiving stable VPA therapy over one year. Plasma ammonia levels and mood symptoms (YMRS, HAM-D) were assessed across four seasons: winter (January), spring (April), summer (July), and autumn (October).

resultsRepeated-measures ANOVA demonstrated a significant main effect of season on plasma ammonia levels (p < 0.001, partial η² = 0.131). Ammonia concentrations peaked during summer (47.41 ± 8.48 µg/dL) and were significantly higher than winter (43.20 ± 8.20 µg/dL, p < 0.001), spring (44.18 ± 7.95 µg/dL, p < 0.001), and autumn (45.10 ± 6.99 µg/dL, p = 0.002). Autumn ammonia levels also remained modestly but significantly higher than winter (p = 0.006). Mood scores remained within the euthymic range across all seasons, with no significant seasonal variation. A modest but significant positive correlation between YMRS scores and ammonia levels was observed exclusively during summer (r = 0.245, p = 0.009).

conclusionsPlasma ammonia levels in VPA-treated patients exhibit a distinct seasonal pattern, peaking during summer despite sustained euthymia. These findings support a seasonally modulated "multi-hit" model of VPA-associated hyperammonemia and highlight the importance of season-informed metabolic monitoring and hydration strategies during warmer months.

Indexed as

AmmoniaAntimanic AgentsBipolar DisorderHyperammonemiaSeasonsValproic AcidAdultFemaleHumansLongitudinal StudiesMiddle AgedProspective StudiesTurkeyAmmoniaAntimanic AgentsValproic AcidBipolar disorderHyperammonemiaSeasonalityValproic acid

Identifiers

PMID42286512
PMCPMC13487916

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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.