Impact of seasonal and lunar cycles on psychological symptoms in the ED: an empirical investigation of widely spread beliefs

Gen Hosp Psychiatry. Mar-Apr 2013;35(2):192-4. doi: 10.1016/j.genhosppsych.2012.10.002. Epub 2012 Nov 13.


Objectives: This study evaluates the impacts of seasonal and lunar cycles on anxiety and mood disorders, panic and suicidal ideation in patients consulting the emergency department (ED) with a complaint of unexplained chest pain (UCP).

Methods: Patients with UCP were recruited from two EDs. Psychiatric diagnoses were evaluated with the Anxiety Disorders Interview Schedule for DSM-IV.

Results: Significant seasonal effects were observed on panic and anxiety disorders, with panic more frequently encountered during spring [odds ratio (OR)=1.378, 95% confidence interval (CI)=1.002-1.896] and anxiety disorders during summer (OR=1.586, 95% CI=1.037-2.425). Except for one significant finding, no significant effects of lunar cycles were observed. These findings encourage ED professionals and physicians to abandon their beliefs about the influence of lunar cycles on the mental health of their patients. Such unfounded beliefs are likely to be maintained by self-fulfilling prophecies.

MeSH terms

  • Aged
  • Chest Pain / psychology
  • Confidence Intervals
  • Cross-Sectional Studies
  • Emergency Service, Hospital / statistics & numerical data
  • Female
  • Health Knowledge, Attitudes, Practice*
  • Humans
  • Male
  • Mental Disorders
  • Middle Aged
  • Moon*
  • Odds Ratio
  • Panic Disorder / diagnosis*
  • Quebec / epidemiology
  • Seasonal Affective Disorder / diagnosis
  • Seasonal Affective Disorder / epidemiology*
  • Seasons
  • Suicidal Ideation
  • Surveys and Questionnaires