Special article
The moon and madness reconsidered

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Abstract

Belief that the full moon is associated with psychiatric disturbance persists despite 50 years research showing no association. This article traces the historical roots of belief in the power of the moon to cause disorders the mind, especially insanity and epilepsy. Putative mechanisms of lunar action are critiqued. It is proposed that modern findings showing lack of lunar effect can be reconciled with pre-modern beliefs in the moon’s power through a mechanism of sleep deprivation. Prior to the advent of modern lighting the moon was a significant source of nocturnal illumination that affected sleep–wake cycle, tending to cause sleep deprivation around the time of full moon. This partial sleep deprivation would have been sufficient to induce mania/hypomania in susceptible bipolar patients and seizures in patients with seizure disorders. The advent of modern lighting attenuated this lunar effect, especially in modern urban areas, where most 20th century studies of lunar effects on the mind have been conducted. The hypothesis presented in this article is open to empirical validation or falsification. Potential tests for the sleep-deprivation hypothesis of lunar action are discussed.

Section snippets

Modern studies of lunar effects

The moon has been associated with mental disorder since antiquity, as reflected by the word ‘lunacy’ itself, which derives from Luna, the Roman goddess of the moon. Belief in the moon’s power to disorder the mind, especially by causing insanity and epilepsy when full, did not perish with the ancient world, but persisted unabated and with few challenges until well into the 19th century. In 1833 the physician Haslam in reviewing his new assignment as director of Bethlehem Royal Hospital in London

Critique of possible etiologic mechanisms for a lunar effect

What is to be made of the discrepancy between popular belief in the power of the moon and empiric evidence that no such power exists? Three general answers can be given to this question. The first is that popular wisdom is right: the moon does affect the mind, but the studies are not capturing the relevant variables. The moon may have effects we are not able to measure, or may have an effect on measured variables that is obscured by noise within the variables themselves. For example, the

The moon as a source of nocturnal illumination

Although the moon shone no brighter in antiquity than it does today, the relative importance of this light in redeeming the night for human affairs has diminished significantly in the last 200 years. It is hard for us to imagine the darkness of a moonless night, even for urbanites, before the advent of gas lighting in the beginning of the 19th century. As late as 1791, London boasted a social group known as the Lunar Society, not because its members had any particular interest in studying the

The effects of moonlight on the mind: sleep deprivation in the genesis of mania and seizures

If the full moon deprived people of sleep in the millennia before gas lighting, could this have served as a possible mechanism for the moon’s effect on the mind? Many studies in this century have shown that prolonged sleep deprivation (i.e. more than 72 h) induces cognitive changes in normal controls, especially mood symptoms and auditory and visual hallucinations Tyler, 1955, Luby et al., 1960, Ross, 1965. More germane to any possible effect of the moon, however, is more recent work

Pre-modern evidence for a specific association of the full moon with mania

The moon’s association with madness, lost now, may have been recognized over the centuries from repeated observations that susceptible people, the majority of whom we would today diagnose as bipolar, were more likely to develop manic symptoms around the full moon than at other times of the month. The 19th century French physician Esquirol (1845) anticipated the argument of this paper by recognizing that the moon’s effect on mental functioning was mediated by its light: ‘It is true that the

Possible methods for validating a sleep-deprivation theory of the moon’s effect on mental functioning

In contrast to mythological or symbolic explanations for why the moon came to be associated with madness and epilepsy, the proposal offered in the paper is potentially falsefiable and may thus be available to empirical validation. A first step would be to demonstrate that artificial lighting dampens any effects the moon may have once exerted. Indirect evidence for this comes from work by Wehr et al. (1995), showing that artificial lighting in urban environments suppresses changes in circadian

References (43)

  • T.A. Wehr et al.

    Treatment of a rapidly cycling bipolar patient by using extended bed rest and darkness to stabilize the timing and duration of sleep

    Biol. Psychiatry

    (1998)
  • M.D. Angus

    The rejection of two explanations of belief in a lunar influence on behavior

  • G. Byrnes et al.

    Crisis calls and lunar cycles: a twenty-year review

    Psychol. Rep.

    (1992)
  • J. Carcopino

    Daily Life in Ancient Rome

    (1941)
  • E. Esquirol

    Mental Maladies, A Treatise On Insanity

    (1845)
  • M.L. Friis et al.

    Stress convulsions

    Arch. Neurol.

    (1974)
  • E.S. Gershon et al.

    Birth-cohort changes in manic and depresive disorders in relatives to bipolar and schizoaffective patients

    Archives of General Psychiatry

    (1987)
  • B.D. Goldman et al.

    Photoperiodism and seasonality in hamsters: role of the pineal gland

  • J.J. Gorvin et al.

    Lunar phases and psychiatric hospital admissions

    Psychol. Rep.

    (1994)
  • W.R. Gowers

    Epilepsy and Other Chronic Convulsive Diseases

    (1885)
  • C. Hering

    Symptoms of the Mind

  • P. Jauhar et al.

    Psychiatric morbidity and time zone changes: a study of patients from Heathrow Airport

    Br J Psychiatry

    (1982)
  • K. Katzeff

    Moon Madness

    (1981)
  • A. Laing

    Lighting

    (1982)
  • M. Langdon-Down et al.

    Times of day in relation to convulsions in epilepsy

    Lancet

    (1929)
  • W.H. Laverty et al.

    Geophysical variables and behavior: LXVIII. Distal and lunar variables and traffic accidents in Saskatchewan

    Psychol. Rep.

    (1992)
  • E.D. Luby et al.

    Sleep deprivation: effects on behavior, thinking, motor performance and biological energy transfer systems

    Psychosom. Med.

    (1960)
  • S.J. Martin et al.

    Suicide and lunar cycles: a critical review over 28 years

    Psychol. Rep.

    (1992)
  • V.M. Mathew et al.

    Attempted suicide and the lunar cycle

    Psychol. Rep.

    (1991)
  • P.A. May et al.

    Indian adolescent suicide: the epidemiologic picture in New Mexico

    Am. Indian and Alaska Native Mental Health Res.

    (1994)
  • D. McG. Kelley

    Mania and the Moon

    Psychoanal. Rev.

    (1942)
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