Morning sunlight reduces length of hospitalization in bipolar depression

J Affect Disord. 2001 Feb;62(3):221-3. doi: 10.1016/s0165-0327(00)00149-x.


Background: Bright artificial light improves non-seasonal depression. Preliminary observations suggest that sunlight could share this effect.

Methods: Length of hospitalization was recorded for a sample of 415 unipolar and 187 bipolar depressed inpatients, assigned to rooms with eastern (E) or western (W) windows.

Results: Bipolar inpatients in E rooms (exposed to direct sunlight in the morning) had a mean 3.67-day shorter hospital stay than patients in W rooms. No effect was found in unipolar inpatients.

Conclusions: Natural sunlight can be an underestimated and uncontrolled light therapy for bipolar depression.

Limitations: This is a naturalistic retrospective observation, which needs to be confirmed by prospective studies.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Bipolar Disorder / therapy*
  • Depression / therapy
  • Depressive Disorder / therapy*
  • Female
  • Humans
  • Inpatients / psychology*
  • Italy
  • Length of Stay / statistics & numerical data*
  • Male
  • Phototherapy / methods*
  • Retrospective Studies
  • Sunlight*