First night effects in post-traumatic stress disorder inpatients

Recent data have suggested that first night effects are attenuated in inpatient depressive subjects. We examined first night effects in 80 inpatients hospitalized for post-traumatic stress disorder (PTSD) as well as non-hospitalized PTSD sufferers and non-ill control subjects. PTSD inpatients exhibited attenuated first night effects compared to non-hospitalized PTSD sufferers and non-trauma-exposed controls. Non-ill combat-exposed subjects also exhibited small first night effects. Within the inpatient sample, severity indices of PTSD, depression and anxiety failed to account for variance in first night effects. These data demonstrate attenuation of first night effects in a new inpatient population and suggest their statistical independence vis-a-vis a range of relevant symptoms. Both the attenuation of first night effects in PTSD inpatients and their accentuation in PTSD outpatients may be indicative of enhanced sensitivity to the sleep environment. Conversely, the trend to small first night effects in non-ill combat-exposed subjects may reflect a dimension of their apparent resistance to traumatic stress.