Table 1.

Similarities between MDD and sickness behavior³⁶–³⁹

	Depression	Sickness behavior
Somatic effects	Fatigue/loss of energy	Fatigue
	Weight loss/weight gain	Weight loss
	Appetite loss/appetite increase	Anorexia
		Sleep disorders
	Insomnia/hypersomnia	Increased body temperature
Behavioral effects	Depressed mood	Depressed mood
	Feelings of worthlessness/guilt	Behavioral despair
		Social withdrawal
	Loss of interest in activities	Anhedonia
	Anhedonia	Cognitive impairment
	Inability to concentrate
	Psychomotor agitation/retardation	Suppression motor behavior
	Recurrent thoughts of death

Note: Similarities between a major depressive episode and sickness behavior. Copyright © 2009, Les Laboratories Servier, Neuilly-sur-Seine, France. Adapted from Lotrich FE. Major depression during interferon-alpha treatment: vulnerability and prevention. Dialogues Clin Neurosci. 2009;11(4):417–425.