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

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.