Doc’s Life THE ASSOCIATION OF LUNAR PHASES AND MENTAL ILLNESS: FACT OR MYTH?

Since ancient times, human has been fascinated by the changing lunar phases – a monthly cycle that takes 29.53 days to complete (Figure 1). Many cultures in the world hold the beliefs that the changing lunar phases affect human behaviour; in particular, full moon has been associated with madness. The word “lunatic” (previously used to mean mentally ill) came from Latin lunaticus which in turn was derived from luna meaning moon.1 phases. In fact agitation was actually less often during full moon.5 o Ammadeo et al did not notice increased number of contacts with community psychiatry based-services with moon phases in a 10-year period.6 o Owen et al failed to establish an association between any lunar phases and violent behaviour.7 o Wilkinson’s study showed no statistical significance in the lunar influence on anxiety or depression consultation in general practice.8 o Barr looked at the influence of the moon on mental health and quality of life. He found significant change of behaviour occurred at the time of the full moon only in subjects diagnosed with schizophrenia.7 o McLay et al evaluated the effect of lunar cycle on psychiatric admissions or emergency evaluations – no significant association.8