title: Lagged relationships among sleep disturbance, fatigue, and depressed mood during chemotherapy.
abstract: OBJECTIVE
  Recent research suggests that sleep disturbance, fatigue, and depressed mood form a symptom cluster in patients treated with chemotherapy. To date, however, no studies have examined lagged relationships among these symptoms during chemotherapy, a time when symptom variability is high. The aim of the current study was to examine lagged changes among daily symptoms during platinum-based chemotherapy.
  
  
  METHODS
  Participants were 78 women with gynecologic cancer (mean age 63 years, SD = 11; 91% Caucasian, 97% non-Hispanic). Sleep disturbance was assessed via wrist actigraphy, whereas fatigue and depressed mood were assessed via daily diary in the week after participants' first chemotherapy infusion. Latent change score models (LCS) were used to examine lagged relationships between symptom pairs.
  
  
  RESULTS
  High levels of sleep disturbance (i.e., minutes awake at night) were associated with earlier subsequent peaks in fatigue, and high levels of fatigue were associated with higher subsequent levels of depressed mood.
  
  
  CONCLUSIONS
  These findings suggest that sleep disturbance, fatigue, and depressed mood occur in a cascade pattern during chemotherapy, in which increases in sleep disturbance contribute to fatigue, which, in turn, contributes to depressed mood. Interventions targeting symptoms early in the cascade, such as sleep disturbance, may provide benefits across multiple downstream symptoms.
authors: Department of Health Outcomes and Behavior, Moffitt Cancer Center, Tampa, FL 33612, USA. heather.jim@moffitt.org
authors: Heather S L
authors: HS
authors: Jim
authors: Paul B
authors: PB
authors: Jacobsen
authors: Kristin M
authors: KM
authors: Phillips
authors: Robert M
authors: RM
authors: Wenham
authors: William
authors: W
authors: Roberts
authors: Brent J
authors: BJ
authors: Small
mesh_terms: D056044:Actigraphy; D000368:Aged; D003863:Depression / Q000209:etiology*; D005221:Fatigue / Q000209:etiology*; D005260:Female; D005833:Genital Neoplasms, Female / Q000188:drug therapy*; D006801:Humans; D008875:Middle Aged; D012893:Sleep Wake Disorders / Q000209:etiology*; D016896:Treatment Outcome; D014851:Wakefulness