Daily variation in post traumatic stress symptoms in individuals with and without probable post traumatic stress disorder

BACKGROUND: Little is known about the extent to which post traumatic stress symptoms (PTSS) vary from day to day in individuals with post traumatic stress disorder (PTSD). This study examined the variation of PTSS by day of the week, and whether daily or day of week variation differs between individuals with and without probable PTSD. METHODS: Subjects (N = 80) were assessed for probable PTSD at enrollment. Using an ecological momentary assessment methodology, PTSS were assessed four times daily by self-report for 15 days. Linear mixed models were used to assess the relationship of PTSS and day of the week. RESULTS: PTSS varied across the seven days of the week among participants with PTSD (p = .007) but not among those without PTSD (p = .559). Among those with PTSD, PTSS were lowest on Saturday. PTSS were higher on weekdays (Monday through Friday) versus weekends (Saturday and Sunday) in those with PTSD (p = .001) but there were no weekday/weekend differences among those without PTSD (p = .144). These variations were not explained by sleep medication, caffeine or alcohol use. CONCLUSIONS: Among individuals with probable PTSD, post traumatic stress symptoms vary by the day of the week, with more symptoms on weekdays compared to weekends. Determination of the factors associated with the daily variation in PTSD symptoms may be important for further developing treatments for PTSD.