Dark-enhanced startle responses and heart rate variability in a traumatized civilian sample: putative sex-specific correlates of posttraumatic stress disorder.

OBJECTIVE: Trauma is associated with increased risk for anxiety disorders such as posttraumatic stress disorder (PTSD). To further understand biologic mechanisms of PTSD, we examined the dark-enhanced startle response, a psychophysiological correlate of anxiety, and heart rate variability (HRV) in traumatized individuals with and without PTSD. The associations of these measures with PTSD may be sex-specific because of their associations with the bed nucleus of the stria terminalis, a sexually dimorphic brain structure in the limbic system that is approximately 2.5 times larger in men than in women. METHODS: The study sample (N = 141) was recruited from a highly traumatized civilian population seeking treatment at Grady Memorial Hospital in Atlanta, Georgia. Psychophysiological responses during a dark-enhanced startle paradigm task included startle magnitude, assessed by eyeblink reflex, and measures of high-frequency HRV, during light and dark phases of the startle session. RESULTS: The startle magnitude was higher during the dark phase than the light phase (mean ± standard error = 98.61 ± 10.68 versus 73.93 ± 8.21 µV, p < .001). PTSD was associated with a greater degree of dark-enhanced startle in women (p = .03) but not in men (p = .38, p interaction = .48). Although HRV measures did not differ between phases, high-frequency HRV was greater in men with PTSD compared with men without PTSD (p = .02). CONCLUSIONS: This study demonstrates that the dark-enhanced paradigm provides novel insights into the psychophysiological responses associated with PTSD in traumatized civilian sample. Sex differences in altered parasympathetic and sympathetic function during anxiety regulation tasks may provide further insight into the neurobiological mechanisms of PTSD.

An Intervention to Promote Sleep and Reduce ADHD Symptoms.

OBJECTIVE: To determine the effect of a sleep hygiene education module and prescriptive sleep routine for children ages 5 through 11 years with attention deficit hyperactivity disorder (ADHD). METHODS: The 20-week pilot project used a pre-/posttest design to assess sleep and ADHD symptoms. The Child Sleep Habits Questionnaire (CHSQ) and Vanderbilt Assessment Scale-Parent Form survey were provided to assess sleep and ADHD behaviors of participants at baseline and 6 weeks after implementation of the sleep hygiene routine. Fifty-three children participated in the project. Of these, 23 scored 42 or greater on the CHSQ, indicating a sleep disorder, and received the intervention. RESULTS: The CHSQ and Vanderbilt scores indicated a significant improvement in sleep quality and reduction in ADHD symptoms after implementation of the sleep hygiene routine (CHSQ: p < .001, d = .928; Vanderbilt Questions 1-9: p < .001, d = .473; Vanderbilt Questions 10-18: p = .004; d = .329). CONCLUSION: A provider-instructed sleep hygiene routine in children with ADHD improves sleep quality and reduces ADHD symptoms.