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Cited by 33Circadian rhythm and melatoninBipolar Disorder and TreatmentSleep and related disorders

Bipolar mood cycles associated with lunar entrainment of a circadian rhythm

Open access
Wehr, Thomas A.·2018·Translational Psychiatry
DOI 10.1038/s41398-018-0203-xPMC PMC6089884
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Abstract

In bipolar disorder, episodes of depression and mania are associated with dramatic disturbances in sleep, which experiments show are likely to contribute to the pathogenesis of the episodes. A recent finding that 18 patients’ manic-depressive cycles oscillated in synchrony with biweekly surges in amplitude of the moon’s tides provided a clue to the cause of the sleep-disturbances. Analyses of one of the patients’ sleep–wake cycles suggest that his mood cycles arose when a circadian rhythm that normally is entrained to dawn and controls the daily onset of wakefulness became entrained instead to 24.8-h recurrences of every second 12.4-h tidal cycle. The finding provides the basis for a comprehensive description of the pathogenesis and pathophysiology of the mood cycle.

AI snapshot

Written from the paper’s full text.

TL;DR

In a 51-year-old man with rapid-cycling bipolar disorder, multi-year sleep–wake records showed both 24.0-h solar and 24.8-h lunar tidal-day periodicities, with mood switches coinciding with new/full moon tidal surges and 180° delay-type phase jumps in wake onset. The author proposes that mood cycles arise when a dawn-entrained circadian component becomes entrained to the 24.8-h lunar tidal day, disrupting sleep timing and duration.

Key findings

  • χ² periodograms detected robust 24.0-h solar-day and 24.8-h lunar-tidal-day periodicities (p < 0.0001) in the first three observation periods; the solar signal was stronger during habitual sleep, while the lunar and solar signals were equal during an ad libitum sleep routine.
  • Switches from depression into mania coincided with 29.5-day recurrences of the new moon, and switches from mania into depression coincided with 29.5-day recurrences of the full moon; both were associated with dramatic delay-type phase-jumps in wake onsets, described as 180° shifts.
  • During a rigid schedule of rest and sleep in darkness for 14 h nightly (reduced gradually to 10 h), the lunar signal disappeared and the patient’s mood cycling stopped.
  • Switches from depression into mania were accompanied by one or more nights of total insomnia.

Methods

  • Single-case longitudinal study of a 51-year-old man diagnosed with bipolar disorder, rapid-cycling type; he recorded daily mood on a 100-mm visual analog scale and daily sleep/wake times on a 24-h log-sheet.
  • Four separate periods were analyzed: 101 days on nortriptyline + tranylcypromine with habitual sleep; 103 days on sertraline with habitual sleep; 122 days on sertraline with ad libitum sleep/wake; and 100 days on sertraline with scheduled dark rest/sleep for 14 h nightly, reduced gradually to 10 h; divalproex sodium was administered throughout.
  • χ² periodogram analyses used ActogramJ, sampling periods from 20.0 to 29.0 h with significance set at P = 0.0001; raster plots divided records into 24-h solar-day or 24.84-h lunar-tidal-day segments and were double-plotted.

Limitations

  • The paper states that the mechanism by which lunar tidal gravity could affect the human body is unclear and is a question for future research; the author also notes that skepticism is warranted.
  • Evident from the design, though not framed as a limitation by the paper: the findings come from a single patient (n = 1) and observational time-series, limiting generalizability and causal inference; there was no experimental manipulation of the lunar cycle.
  • Evident from the treatment context: antidepressants, divalproex sodium, and varying sleep schedules may confound the sleep–wake and mood observations; the paper does not report statistical control for these factors.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1038/s41398-018-0203-x

Cites

30 of 30 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 37 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    In the first three observation periods, χ2 periodograms detected robust periodicities corresponding to the 24.0-h solar day and the 24.8-h lunar tidal day.

    “In the first three observation periods, χ2 periodograms detected robust periodicities that corresponded to the 24.0-h solar day (p < 0.0001) and the 24.8-h lunar tidal day (p < 0.0001) (Figs. 1 and 2).”
    Quote in the paperSubstantial claim
  • Findingown data

    When the patient followed his habitual sleep-routine, the solar signal was stronger than the lunar one.

    “When the patient followed his habitual sleep-routine, the solar signal was stronger than the lunar one (Fig. 1).”
    Quote in the paperNot a substantial claim
  • Findingown data

    The two periodicities (solar and lunar) were consistently present in three different conditions of measurement comprising hundreds of sleep-wake cycles.

    “Moreover, the two periodicities were consistently present in three different conditions of measurement comprising hundreds of sleep–wake cycles (Figs. 1 and 2).”
    Quote in the paperSubstantial claim
  • Findingown data

    Nights of total insomnia accompanied switches from depression to mania.

    “Nights of total insomnia accompanied switches from depression to mania.”
    Quote in the paperSubstantial claim
  • Findingown data

    Coupling of the sleep-wake cycle to the 24.8-h lunar tidal day relative to its coupling to the 24-h solar day increased during an ad libitum sleep routine.

    “Coupling of the sleep–wake cycle to the 24.8-h lunar tidal day relative to its coupling to the 24-h solar day increased during an ad libitum sleep routine.”
    Quote in the paperSubstantial claim
  • May combine two claims. 19
  • Classified as probably not a substantial claim. 4

  • May combine two claims.

    Findingown data

    When the patient adhered to a rigid schedule of rest and sleep during long periods of darkness every night, the lunar signal disappeared and his mood cycling stopped.

    “When he adhered to a rigid schedule of rest and sleep during long periods of darkness every night, the lunar signal disappeared and his mood cycling stopped (Fig. 3).”
    • Also stated in: § Discussion · plain
      “When the patient adhered to a rigid schedule of rest and sleep during long periods of darkness every night, the lunar signal disappeared and his mood cycling stopped (Fig. 3).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    New-moon and full-moon surges in the tidal cycle's strength as a forcing cycle were associated with 180° delay-type phase-jumps in wake-onset and with switches between depression and mania.

    “New-moon and full-moon surges in the tidal cycle’s strength as a forcing cycle were associated with 180° delay-type phase-jumps in wake-onset and with switches between depression and mania.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Phase-jumps in the timing of wake-onsets coincide with recurrences of new moons and with switches from depression into mania.

    “Phase-jumps in the timing of wake-onsets coincide with recurrences of new moons (filled circles) and with switches from depression (–) into mania (+).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Switches from depression into mania coincided with 29.5-day recurrences of the new moon, while switches from mania into depression coincided with 29.5-day recurrences of the full moon-times when the tidal cycle's amplitude and its strength as a forcing cycle would have been the greatest.

    “Switches from depression into mania coincided with 29.5-day recurrences of the new moon, while switches from mania into depression coincided with 29.5-day recurrences of the full moon—times when the tidal cycle’s amplitude and its strength as a forcing cycle would have been the greatest (Figs. 1 and 4).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    When the patient relaxed his adherence to a 24-h schedule, his sleep-wake cycle's entrainment to the lunar tidal day and its relative coordination with the solar day were more clearly evident, and the 24.8-h lunar signal and the 24-h solar signal in the periodogram became equal in strength.

    “When the patient relaxed his adherence to a 24-h schedule, his sleep–wake cycle’s entrainment to the lunar tidal day and its relative coordination with the solar day were more clearly evident, and the 24.8-h lunar signal (p < 0.0001) and the 24-h solar signal in the periodogram became equal in strength”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Disrupting sleep of bipolar patients can induce mania and restoring sleep can induce depression.

    “Experiments have shown that disrupting sleep of bipolar patients can induce mania and restoring sleep can induce depression4–8.”
    Quote in the paperSubstantial claim0 of 5 sources checked
    • cites [4] Wehr, T. A., Wirz-Justice, A., Goodwin, F. K., Breitmeier, J. & Craig, C. 48-hour sleep-wake cycles in manic-depressive illness: naturalistic observations and sleep deprivation experiments. Arch. Gen. Psychiatry 39, 559–565 (1982). source

      Not checked in the free run.

    • cites [5] Schilgen, B. & Tölle, R. Partial sleep deprivation as therapy for depression. Arch. Gen. Psychiatry 37, 267–271 (1980). source

      Not checked in the free run.

    • cites [6] Sack, D. A., Rosenthal, N. E., Duncan, W. C., Mendelson, W. B. & Wehr, T. A. Early versus late partial sleep deprivation therapy of depression. Acta Psychiatr. Scand. 77, 219–224 (1988). source

      Not checked in the free run.

    • cites [7] Benedetti, F. et al. Sleep phase advance and lithium to sustain the antidepressant effect of total sleep deprivation in bipolar depression. J. Psychiatr. Res. 35, 323–329 (2001). source

      Not checked in the free run.

    • cites [8] Wu, J. C. & Bunney, W. E. Jr. Rapid and sustained antidepressant response with sleep deprivation and chronotherapy in bipolar disorder. Biol. Psychiatry 66, 298–301 (2009). source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Sleep is abnormally long in depression and abnormally short in mania, and it is often completely absent during switches from depression to mania.

    “Sleep is abnormally long in depression and abnormally short in mania, and it is often completely absent during switches from depression to mania4.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [4] Wehr, T. A., Wirz-Justice, A., Goodwin, F. K., Breitmeier, J. & Craig, C. 48-hour sleep-wake cycles in manic-depressive illness: naturalistic observations and sleep deprivation experiments. Arch. Gen. Psychiatry 39, 559–565 (1982). source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Premisecitation

    Pacemaker cells in the suprachiasmatic nucleus of the hypothalamus are organized in separate networks.

    “Pacemaker cells, which individually generate circadian rhythms in the suprachiasmatic nucleus of the hypothalamus, are organized in separate networks16.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [16] Meijer, J. H., Michel, S., vanderLeest, H. T. & Rohling, J. H. Daily and seasonal adaptation of the circadian pacemaker requires plasticity of the SCN neuronal network. Eur. J. Neurosci. 32, 2143–2151 (2010). source

      Not checked in the free run.

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    One network (E) is entrained to dusk and controls the timing of sleep-onset; another network (M) is entrained to dawn and controls the timing of wake-onset.

    “One network (E) is entrained to dusk and controls the timing of sleep-onset. Another network (M) is entrained to dawn and controls the timing of wake-onset.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Under certain circumstances, the oscillations of E and M can become dissociated from one another; coupling forces between the two components continue to operate and tend to draw the components into either of two metastable modes of coupling that are 180° apart.

    “Under certain circumstances, the oscillations of E and M can become dissociated from one another. In this situation, coupling forces between the two components continue to operate and tend to draw the components into either of two metastable modes of coupling that are 180° apart17,19.”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [17] Evans, J. A., Gorman, M. R. In synch but not in step: circadian clock circuits regulating plasticity in daily rhythms. Neurosci. 320, 259–280 (2016). source

      Not checked in the free run.

    • cites [19] Wehr, T. A. In short photoperiods, human sleep is biphasic. J. Sleep Res. 1, 103–107 (1992). source

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    Consistent with the hypothesis that this entrainment drove the mood cycles, the phase-jumps invariably were accompanied by switches between depression and mania and by abrupt changes in the interval between sleep-onset and wake-onset.

    “Consistent with the hypothesis that this entrainment drove the mood cycles, the phase-jumps invariably were accompanied by switches between depression and mania and by abrupt changes in the interval between sleep-onset and wake-onset (Fig. 4).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    Thereafter, an ongoing entrainment of wake-onset to the 24.8-h lunar cycle opened the phase-angle and produced the short periods of sleep that are characteristic of mania.

    “Thereafter, an ongoing entrainment of wake-onset to the 24.8-h lunar cycle opened the phase-angle and produced the short periods of sleep that are characteristic of mania.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    The shifts were manifested in behavior as switches between depression and mania, and they caused sleep to be short in mania and long in depression.

    “The shifts were manifested in behavior as switches between depression and mania, and they caused sleep to be short in mania and long in depression.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    The model presented here attributes uncoupling of the rhythm from the day-night cycle to its entrainment to the lunar cycle, and it specifies sleep and wakefulness as mediators of the rhythm's effects on mood.

    “The model presented here attributes uncoupling of the rhythm from the day–night cycle to its entrainment to the lunar cycle, and it specifies sleep and wakefulness as mediators of the rhythm’s effects on mood.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    A delayed phase-angle could occur if the intrinsic rhythm of pacemaker cells was abnormally slow, or if their response to the phase-resetting effect of light was abnormally weak.

    “A delayed phase-angle could occur if the intrinsic rhythm of pacemaker cells was abnormally slow, or if their response to the phase-resetting effect of light was abnormally weak.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    The findings in this patient identify an external force that drives the mood cycle and the site and mechanism of its action in the brain.

    “They identify an external force that drives the mood cycle and the site and mechanism of its action in the brain.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationcitation

    This risk could be increased by the administration of certain antidepressants, which have been shown to slow the oscillations of the pacemaker and to interfere with its entrainment to light-dark cycles in experimental animals, and to cause rapid cycling in certain bipolar patients.

    “This risk could be increased by the administration of certain antidepressants, which have been shown to slow the oscillations of the pacemaker and to interfere with its entrainment to light–dark cycles in experimental animals, and to cause rapid cycling in certain bipolar patients27–29.”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [27] Duncan, W. C., Tamarkin, L., Sokolove, P. & Wehr, T. A. Chronic clorgyline treatment of the Syrian Hamster: an analysis of circadian effects. J. Biol. Rhythms 3, 305–322 (1988). source

      Not checked in the free run.

    • cites [28] Duncan, W. C. Jr, Johnson, K. A. & Wehr, T. A. Decreased sensitivity to light of the photic entrainment pathway during chronic clorgyline and lithium treatments. J. Biol. Rhythms 13, 330–346 (1998). source

      Not checked in the free run.

    • cites [29] Wehr, T. A., Sack, D. A., Rosenthal, N. E. & Cowdry, R. W. Rapid cycling affective disorder: contributing factors and treatment responses in 51 cases. Am. J. Psychiatry 145, 179–184 (1988). source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Bipolar patients tend to be "evening types" who have a delayed phase-angle of entrainment to the day-night cycle.

    “Bipolar patients tend to be “evening types” who have a delayed phase-angle of entrainment to the day–night cycle26.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [26] Melo, M. C. A., Abreu, R. L. C., Neto, V. B. L., de Bruin, P. F. C. & de Bruin, V. M. S. Chronotype and circadian rhythm in bipolar disorders: a systematic review. Sleep Med. Rev. 34, 46–58 (2017). source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Interpretationreasoning

    The episodes of depression and mania that occur in the rapid-cycling patient as the dawn-tracking component goes in and out of phase with the dusk-tracking component could then be viewed as seasonal behaviors that have been compressed into a truncated "year" of brief "winters" and brief "summers" with abrupt transitions between them.

    “The episodes of depression and mania that occur in the rapid-cycling patient as the dawn-tracking component goes in and out of phase with the dusk-tracking component could then be viewed as seasonal behaviors that have been compressed into a truncated “year” of brief “winters” and brief “summers” with abrupt transitions between them.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Interpretationreasoning

    Either of these possibilities could be a risk factor for developing rapid-cycling by making a circadian rhythm susceptible to capture by the slower-than-24-h cycle of the lunar tidal day.

    “Either of these possibilities could be a risk factor for developing rapid-cycling by making a circadian rhythm susceptible to capture by the slower-than-24-h cycle of the lunar tidal day.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    This patient's rapid-cycling bipolar disorder can be viewed as a disorder of two networks in the suprachiasmatic nucleus that track seasonal changes in the photoperiod, a disorder in which a network that normally is entrained to dawn becomes entrained instead to the lunar tidal day.

    “Thus, this patient’s rapid-cycling bipolar disorder can be viewed as a disorder of two networks in the suprachiasmatic nucleus that track seasonal changes in the photoperiod, a disorder in which a network that normally is entrained to dawn becomes entrained instead to the lunar tidal day.”
    Quote in the paperSubstantial claim
21 of 21

  • The paper relies on this without support.

    The lunar tidal cycle is capable of entraining a human circadian rhythm (or the 24.8-h periodicity in the patient’s sleep–wake cycle reflects entrainment to the lunar tidal day rather than another cause).

    “The nature of the mechanism that makes it possible for an object as small as the human body to be affected by the minute changes in gravity that are associated with lunar tidal cycles is unclear and is a question for future research.”
1 of 1

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • The paper's principal results are consistent with earlier studies on menstrual, mood, and sleep-wake cycles, which showed that humans are sensitive to the Moon's luminance cycle and synchronize with it.

    “Our principal results are consistent with the results of earlier studies on menstrual, mood, and sleep-wake cycles, which revealed that humans are sensitive to the Moon’s luminance cycle and even synchronize with it (10, 13–15, 29, 39, 40).”

    From Women temporarily synchronize their menstrual cycles with the luminance and gravimetric cycles of the Moon (2021) · cites this paper as [29]

    The Results (Periodicities in the sleep–wake cycle) report that one bipolar patient’s sleep–wake cycle was coupled to the lunar tidal day, supporting a narrower claim about lunar synchronization of sleep and mood. The paper does not report menstrual cycles or establish sensitivity to the Moon’s luminance cycle; its Introduction instead frames the proposed lunar influence in terms of gravitational tides. (LLM, conf=0.88)

    Experimental — accuracy not yet measured

Cites

Flagged first, then by citations

Research works printed but not linked: 2

  1. Wehr T. A. in Sleep and Biological Rhythms (eds Montplaisir J., & Godbout R.) 42–86 (Oxford Press, London, 1990).
  2. Halberg F. Physiological considerations underlying rhythmometry, with special reference to emotional illness. In Symposium Bell-Air III, Mason et Cie, Geneva, 1967, pp. 73–126.

Cited by

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Related

Authors
Wehr, T. A.
Affiliations
National Institute of Mental Health (US)
Corresponding author
Wehr, Thomas A.
ORCID
Wehr, Thomas A.
Venue
Translational Psychiatry
Publisher
Springer Science and Business Media LLC
Published
2018-08-13
Volume
8
Issue
1
Pages
151-151
ISSN
2158-3188 (ISSN-L)
DOI
10.1038/s41398-018-0203-x
PMC
PMC6089884
OpenAlex
W2885275531
Semantic Scholar
e7ce2f2a04ac12f0ddeb0bec9349bb3e145b6424
Cited by
33
References
30
Citations by year
2026: 7 · 2025: 4 · 2024: 1 · 2023: 2 · 2022: 1 · 2021: 8 · 2020: 5 · 2019: 5
FWCI
2.53
Type
journal article
Language
en
Open access
Licence
Locations
  • Translational Psychiatry (publishedVersion, cc-by)
  • Europe PMC (PubMed Central) (publishedVersion, other-oa)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion)
Funders
  • Australian Government
  • National Institutes of Health
  • National Institute of Mental Health
Topics
  • Life Sciences › Neuroscience › Endocrine and Autonomic Systems › Circadian rhythm and melatonin
  • Health Sciences › Medicine › Psychiatry and Mental health › Bipolar Disorder and Treatment
  • Social Sciences › Psychology › Experimental and Cognitive Psychology › Sleep and related disorders
Keywords
bipolar disorder, circadian rhythm, tidal cycles, sleep disorders, mania, depression
MeSH terms
Affect, Bipolar Disorder, Circadian Rhythm, Humans, Male, Middle Aged, Sleep, Sleep Wake Disorders, Wakefulness, Moon

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