Abstract
Peter I. H. Parry, Department of Psychological Medicine, Women's and Children's Hospital, Adelaide, Australia:
I was interested to see the study of Owen et al. [1] on whether there was a relationship between the lunar cycle, in particular the time of the full moon, and violent behaviour in a psychiatric inpatient setting. I was not surprised by the result of no significant relationship found. As the paper noted, the belief is common among staff of psychiatric wards and also among the general public, and the belief has a long history attested to by the old term ‘lunatic’.
I came up with a simple, and I'm sure not original, theory as to why such a widespread belief arose when asked about it by my hairdresser recently. He suggested that astrological electromagnetic forces associated with the full moon were a cause of psychiatric symptoms and disorder. In pondering this challenge to a debate, I recalled a couple of experiences.
The first was the time some years ago that we spent a few weeks in my partner's ancestral village in northern Greece. The one and only streetlight was by the church, and finding one's way home down slippery, rough-hewn laneways at night was heavily dependent on the amount of cloud and moon. A full moon made such a difference, not only in the narrow laneways, but illuminating a magical countryside that beckoned one to travel far beyond the houses of cousins.
The second memory was of riding my pushbike home in the early hours after a late duty as a registrar at Glenside Hospital. On a minor road, I was confronted by a tall, gaunt figure with staring eyes clad in a great-coat, striding, almost goose-stepping, down the centre of the street; a patient of mine. The night may have had a bit of a moon, but the street lamps provided more than sufficient illumination out in the centre of the street away from the shadow of thick tree foliage in Adelaide's eastern suburbs, although paranoia or some other impulse may have also guided him to the centre of the road.
I explained to my hairdresser how insomnia is a common accompaniment of mental illness, and in conjunction with these anecdotes, formed the opinion that in centuries before ours the nocturnal wanderings of those with psychiatric disorder were far more noticeable during a fullish moon. On a new moon or a moonless night, one would confine one's wanderings to indoors or likely limp home from the nearest pothole. The observed nocturnal wanderings of troubled souls when moonlight permitted led to the idea of ‘lunacy’. The idea, therefore, arose as an observational error. (One could talk of melatonin and the biochemistry of light, but that is not inconsistent with the above hypothesis).
My hairdresser could see my meaning, but he still preferred his own theory.