The effects of a dual orexin receptor antagonist on fear extinction memory and sleep in mice: Implications for exposure therapy.

Extinction of conditioned fear is considered a fundamental process in the recovery from posttraumatic stress disorder and anxiety disorders. Sleep, especially rapid-eye-movement (REM) sleep, has been implicated in promoting extinction memory. The orexin system contributes to the regulation of sleep and wakefulness and emotional behaviors. In rodents, administrations of an orexin receptor antagonist following fear extinction training enhanced consolidation of extinction memory. Although orexin antagonists increase sleep, including REM sleep, the possible contribution of sleep to the effects of orexin antagonists on extinction memory has not been examined. Therefore, this study examined the effects of suvorexant, a dual orexin receptor antagonist, on extinction memory and sleep and their associations in mice. C57BL/6 mice underwent sleep recording for 24 h before and after contextual fear conditioning with footshocks and extinction learning during the early light phase or early dark phase. Mice were systemically injected with either 25 mg/kg of suvorexant or vehicle immediately after the extinction session. We found that suvorexant neither altered sleep nor improved extinction memory recall compared with vehicle. The higher percentages of REM sleep during the post-extinction dark phase were associated with lower extinction memory recall and greater freezing responses to the fear context. Results also indicate that animals did not reach complete extinction of fear with the fear extinction training protocol used in this study. These findings suggest that promoting REM sleep may not enhance fear extinction memory when extinction of fear is incomplete.

Evaluation of suvorexant for trauma-related insomnia.

STUDY OBJECTIVES: Effective pharmacological treatments for sleep disturbance related to trauma with and without co-occurring posttraumatic stress disorder (PTSD) are needed. There is debate regarding what effects on rapid eye movement sleep (REMS) would be beneficial. Suvorexant is the first dual orexin receptor antagonist (DORA) approved for the treatment of insomnia. In contrast to most psychotropic agents, DORAs can enhance REMS while reducing arousal. We evaluated 6 weeks of suvorexant treatment for trauma-related insomnia in a double-blind, placebo-controlled clinical trial with clinical and polysomnographic evaluation. METHODS: Participants with insomnia that followed a traumatic event were recruited from the community. Representation of current, past-only, and never having met criteria for PTSD was similar and most participants had experienced trauma-related nightmares. Participants were randomly assigned to receive suvorexant or placebo, initially at 10 mg and increased to 20 mg after 1 week, if tolerated. Polysomnography was obtained for screening, at baseline, and at 2 weeks of treatment. RESULTS: The thirty-seven evaluable participants had significant improvement of PTSD and insomnia symptoms, however, there were no significant interactions with treatment condition. Medication was well tolerated with only one dropout being related to side effects. Within the suvorexant group increased REM segment duration correlated with concurrent PTSD symptom reduction. Nightmares remitted in all of the participants who received suvorexant and all but one of those receiving placebo. CONCLUSIONS: A robust placebo response undermined detecting a medication effect. Further evaluation of DORAs for trauma-related insomnia, as well as factors contributing to placebo-response, are warranted.

Blocking the orexin system following therapeutic exposure promoted between session habituation, but not PTSD symptom reduction.

There is a need to identify strategies to increase the effectiveness of treatments for posttraumatic stress disorder (PTSD). Sleep is often disturbed in PTSD and has been implicated in learning processes that underlie recovery from PTSD, including extinction of conditioned fear. Our prior study suggested that diminished arousal during sleep may enhance benefits of therapeutic exposure for PTSD. The orexin system regulates arousal, and blocking the system diminishes arousal and promotes sleep. We, therefore, examined whether a dual orexin receptor antagonist, suvorexant, administered following evening exposure sessions, would enhance their therapeutic effectiveness for PTSD. In this randomized double-blind placebo-controlled trial, adults with PTSD completed four written narrative exposure (WNE) sessions, two of which took place in the evening, and two the next morning. Participants received either suvorexant or placebo after each evening WNE. We found that suvorexant increased N3 sleep and decreased N2 sleep and rapid-eye-movement latency measured by polysomnography. Between session habituation indexed by subjective distress ratings was greater with suvorexant, but there was no group difference in the reduction of PTSD severity from baseline to 1-week follow-up. No safety concerns emerged. The present findings provide preliminary support for enhancement of an effect of therapeutic exposure for PTSD by suvorexant. Further studies with larger samples are needed to translate the present findings into clinical applications, including studies to develop optimal suvorexant administration and exposure session schedules to achieve persistent benefits to sleep and possibly greater treatment augmentation.

Impacts of sex and the estrous cycle on associations between post-fear conditioning sleep and fear memory recall.

Women are at greater risk than men for developing posttraumatic stress disorder (PTSD) after trauma exposure. Sleep, especially rapid-eye-movement sleep (REMS), has been considered a contributing factor to the development of PTSD symptoms through its effects on the processing of emotional memories. However, it remains unknown if sex and sex hormones play a role in the hypothesized impact of sleep on the development of PTSD. Animal models have methodological advantages over human studies in investigating this research question; however, animal models of sleep in PTSD have been tested only with males. C57BL/6 mice (7 males and 15 females) were exposed to 15 footshocks in a footshock chamber, and 5 min after the last footshock, were returned to their home cages for telemetric electroencephalographic sleep recording. Nine to thirteen days later, mice were returned to the footshock chamber for 10 min without footshocks. Fear recall rates were computed by comparing freezing behaviors in the footshock chamber immediately after the footshocks to those during fear context reexposure. Males had significantly lower recall rates compared to metestrous females (that received footshocks on metestrus). Overall, males slept more than both proestrous females (that received footshocks on proestrus) and metestrous females during the dark period. Regression analyses revealed that average REMS episode durations after footshocks were differentially associated with recall rates across groups, such that the association was positive in males, but negative in proestrous females. Results suggest that both sex and the estrous cycle modulate the associations between REMS continuity and fear memory consolidation.

Emotional response to perceived racism and nocturnal heart rate variability in young adult African Americans.

BACKGROUND: Heightened autonomic nervous system (ANS) arousal is a well-established contributor to the effect of stress on adverse cardiovascular health outcomes which disproportionately affect African Americans. ANS arousal is normally attenuated during sleep and compromise of this shift is associated with multiple adverse cardiovascular outcomes. Parasympathetic nervous system (PNS) dominance during sleep can be altered by stress. Racism has been recognized to have many negative health consequences in African Americans. Perceived racism has been linked to ANS activity, however, we are not aware of prior research on racism and nocturnal ANS balance. OBJECTIVE: To examine relationships between perceived racism and nocturnal ANS activity indexed by heart rate variability (HRV) in healthy African American men and women age 18-35. METHODS: Fifty-four participants completed the Perceived Racism Scale and had 24-hour ambulatory electrocardiogram recordings in their homes. Power spectral analysis was used to derive normalized high frequency (nHF) to index PNS activity which was computed by 5-minute epochs during wake and sleep. RESULTS: Endorsement of racism and negative emotional reactions during the past year were inversely related to nHF during time in bed. Multiple regression analysis indicated that negative emotional reactions were a significant predictor of nHF during the sleep period F(2,54) = 4.213, p = .020, R2 = 0.135 (adjusted R2 = 0.103). Relationships during wake were not statistically significant. CONCLUSION: Findings suggest that perseverative thoughts triggered by negative emotional reactions to racism influencing nocturnal ANS activity may be a pathway by which perceived racism affects health. Support: 3UL1TR001409-02S1 and R01HL087995 to Dr. Mellman.

Gender and age interact to predict the development of posttraumatic stress disorder symptoms following a motor vehicle accident.

OBJECTIVE: Women have a greater overall risk of developing posttraumatic stress disorder (PTSD) than men after exposure to trauma. In addition to gender, other sociodemographic factors have been identified as risk factors for PTSD; however, research has typically examined these factors separately. Age has been found to contribute to the development of psychiatric disorders, and both linear and curvilinear relationships have been reported between age and risk of developing PTSD. Recent research has suggested that this relationship may vary depending on gender. METHOD: We performed a secondary analysis of data from a prospective study of 287 (164 men, 123 women) motor vehicle accident (MVA) patients (aged 18-81) who completed clinical interviews 6 weeks, 6 months, and/or 1 year after an MVA. RESULTS: Overall, women developed more severe PTSD symptoms than men; however, gender differences were small in the young (18-24 years) and the old (55 and older) groups. In women, age was not associated with PTSD symptoms at 6 weeks and 6 months; however, age was curvilinearly associated with PTSD severity at 1-year post-MVA such that middle-aged women reported greater symptom severity than younger and older women. Prior trauma exposure and social support mediated this relationship. In men, PTSD severity was not associated with age, but was related to income and social support. CONCLUSIONS: These findings highlight age-based subgroups of women at elevated risk for PTSD following a traumatic injury and suggest that psychosocial intervention with middle-aged women following trauma exposure may help reduce the risk of persistent PTSD symptoms. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Impact of strain, sex, and estrous cycle on gamma butyrolactone-evoked absence seizures in rats.

Childhood absence epilepsy (CAE) is the most common pediatric epilepsy syndrome and is characterized by typical absence seizures (AS). AS are non-convulsive epileptic seizures characterized by a sudden loss of awareness and bilaterally generalized synchronous 2.5-4 Hz spike and slow-wave discharges (SWD). Gamma butyrolactone (GBL) is an acute pharmacological model of AS and induces bilaterally synchronous SWDs and behavioral arrest. Despite the long use of this model, little is known about its strain and sex-dependent features. We compared the dose-response profile of GBL-evoked SWDs in three rat strains (Long Evans, Sprague-Dawley, and Wistar), and examined the modulatory effects of estrous cycle on SWDs in female Wistar rats. We evaluated the number of seizures, the cumulative time seizing, and the average seizure duration as a function of dose, strain, and sex/estrous phase. Long Evans rats displayed the greatest sensitivity to GBL, followed by Wistar rats, and then by Sprague-Dawley rats. GBL-evoked SWDs were modulated by estrous cycle in female rats, with the lowest sensitivity to GBL occurring during metestrus. Wistar rats showed the greatest variability as a function of dose, and the least variability within dose; these features make this strain desirable for interventional studies. Moreover, our finding that the SWD response to GBL differs as a function of estrous cycle underscores the importance of cycle monitoring in studies examining female animals using this model. Together, these strain and sex-dependent findings provide guidance for future studies.

Impact of Traumatic Stress on Sleep and Management Options in Women.

After exposure to traumatic stress, women are at greater risk than men for developing symptoms of some psychiatric disorders, including insomnia and nightmares. Sleep disturbance is one of the most refractory symptoms of posttraumatic stress disorder. Women were included in a few studies that examined efficacy of psychological or pharmacologic interventions for trauma-related sleep disturbances. Studies demonstrated preliminary evidence for efficacy of cognitive behavioral therapy for insomnia, imagery rehearsal therapy, and combinations of these techniques in treating insomnia and nightmares in trauma-exposed women. Prazosin as an adjunct to ongoing treatment is a potentially efficacious strategy for treating trauma-related nightmares in women.

Neighborhood stress and autonomic nervous system activity during sleep.

Study Objectives: Stressful neighborhood environments are known to adversely affect health and contribute to health disparities but underlying mechanisms are not well understood. Healthy sleep can provide a respite from sustained sympathetic nervous system (SNS) activity. Our objective was to evaluate relationships between neighborhood stress and nocturnal and daytime SNS and parasympathetic nervous system (PNS) activity. Methods: Eighty-five urban-residing African Americans (56.5% female; mean age of 23.0) participated. Evaluation included surveys of neighborhood stress and sleep-related vigilance, and continuous electrocardiogram (ECG) and actigraphic recording in participants' homes from which heart rate variability (HRV) analysis for low frequency/high frequency (LF/HF) ratio and normalized high frequency (nHF), as indicators of SNS and PNS activity, respectively, and total sleep time (TST), and wake after sleep onset were derived. Results: All significant relationships with HRV measures were from the sleep period. Neighborhood disorder correlated negatively with nHF (r = -.24, p = .035). There were also significant correlations of HRV indices with sleep duration and sleep fears. Among females, LF/HF correlated with exposure to violence, r = .39, p = .008, and nHF with census tract rates for violent crime (r = -.35, p = .035). In a stepwise regression, TST accounted for the variance contributed by violent crime to nHF in the female participants. Conclusions: Further investigation of relationships between neighborhood environments and SNS/PNS balance during sleep and their consequences, and strategies for mitigating such effects would have implications for health disparities.

Nocturnal autonomic nervous system activity and morning proinflammatory cytokines in young adult African Americans.

Compromised sleep and increased sympathetic nervous system (SNS) activity are implicated in the pathogenesis of, and disparities in, cardiovascular disease. Parasympathetic dominance during sleep may be important for cardiovascular health. Sleep and autonomic balance influence immune activity, which impacts atherogenesis. We evaluated relationships between autonomic balance during sleep and morning levels of the immune activating cytokines, C-reactive protein (CRP) and interleukin (IL)-6. Ninety-four (59 female) young adult African Americans without medical conditions and substance use disorders spent 2 consecutive nights in a clinical research unit for sleep recordings and blood drawing on awakening. Cardiac tracings from the second sleep recording were analysed for heart rate variability (HRV). Body mass index was the only non-HRV measure correlated with cytokine levels. Indicators of SNS activity for the presleep, and first non-rapid eye movement (REM) and REM sleep periods were correlated independently with morning IL-6 levels. Altered autonomic balance during sleep may be a modifiable factor that influences immune activation.

Sleep and Processing of Trauma Memories.

Sleep has been implicated in learning processes that appear to underlie recovery from posttraumatic stress disorder (PTSD). The importance of quality and timing of sleep following exposure-based therapies has been suggested. The present study evaluated relationships between sleep and adaptive emotional processing following written narrative exposure (WNE) to memories of traumatic events experienced by participants with clinically significant PTSD symptoms. Participants included 21 urban-residing nontreatment-seeking adults with full or subthreshold symptoms of PTSD who completed 4 sessions of 30-min WNE with the first session either in the evening or the morning. There was a significant reduction of PTSD symptom severity after WNE sessions (partial η = .65), but there was no interaction between group assignment based on the initial session's proximity to sleep and initial reduction of PTSD symptom severity (partial η = .01). Polysomnography following evening WNE revealed increased duration of total sleep and N2%, reduced N3%, and increased eye movement density during REM sleep compared with baseline recordings (dz = 0.65 to 1.15). Reduced N3% and increased REM density were associated with less improvement of PTSD symptoms (r = .58 & -.63). These findings suggest a relationship between preservation of diminished arousal during sleep and adaptive trauma memory processing.

Expression and methylation in posttraumatic stress disorder and resilience; evidence of a role for odorant receptors.

Post-traumatic stress disorder (PTSD) is a common and potentially disabling disorder that develops in 1/5 to 1/3 of people exposed to severe trauma. Twin studies indicate that genetic factors account for at least one third of the variance in the risk for developing PTSD, however, the specific role for genetic factors in the pathogenesis of PTSD is not well understood. We studied genome-wide gene expression and DNA methylation profiles in 12 participants with PTSD and 12 participants who were resilient to similar severity trauma exposure. Close to 4000 genes were differentially expressed with adjusted p<0.05, fold-change >2, with all but 3 upregulated with PTSD. Eight odorant/olfactory receptor related genes were up-regulated with PTSD as well as genes related to immune activation, the Gamma-Aminobutyric Acid A (GABAA) receptor, and vitamin D synthesis. No differences with adjusted significance for DNA methylation were found. We conclude that increased gene expression may play an important role in PTSD and this expression may not be a consequence of DNA methylation. The role of odorant receptor expression warrants independent replication.

The impact of posttraumatic stress disorder versus resilience on nocturnal autonomic nervous system activity as functions of sleep stage and time of sleep.

Posttraumatic stress disorder (PTSD) has been associated with sleep disturbances including alterations in sleep stages and recently, elevated nocturnal autonomic nervous system (ANS) arousal (i.e., dominance of the sympathetic nervous system over the parasympathetic nervous system). Data suggest that sleep contributes to the regulation of ANS activity. In our previous ambulatory heart rate variability (HRV) monitoring study, strong relationships between sleep and nocturnal ANS activity in resilient participants (i.e., individuals who had never had PTSD despite exposure to high-impact trauma) were not seen with PTSD. In this study, we examined the impact of PTSD vs. resilience on ANS activity as a function of sleep stage and time of sleep. Participants (age 18-35) with current PTSD (n=38) and resilience (n=33) completed two overnight polysomnography recordings in a lab setting. The second night electrocardiogram was analyzed for frequency domain HRV parameters and heart rate within rapid-eye-movement (REM) and non-REM (NREM) sleep periods. Results indicated that ANS arousal indexed by HRV was greater during REM compared with NREM sleep and that the REM-NREM difference was greater in the PTSD than in the resilient participants. This effect of PTSD was reduced to non-significance when analyses controlled for REM sleep percentage, which was lower with PTSD. Exploratory analyses revealed that the REM-NREM difference in HRV was correlated with REM sleep percentage in resilient participants, but not with PTSD. In contrast with our data from home settings, the present study did not find increased overall nocturnal ANS arousal with PTSD. Analyses did reveal higher heart rate during initial NREM sleep with more rapid decline over the course of NREM sleep with PTSD compared with resilience. Findings suggest that elevated ANS arousal indexed by heart rate with PTSD is specific to the early part of sleep and possible impairment in regulating ANS activity with PTSD related to REM sleep.

Autonomic and inflammatory consequences of posttraumatic stress disorder and the link to cardiovascular disease.

Stress- and anxiety-related disorders are on the rise in both military and general populations. Over the next decade, it is predicted that treatment of these conditions, in particular, posttraumatic stress disorder (PTSD), along with its associated long-term comorbidities, will challenge the health care system. Multiple organ systems are adversely affected by PTSD, and PTSD is linked to cancer, arthritis, digestive disease, and cardiovascular disease. Evidence for a strong link between PTSD and cardiovascular disease is compelling, and this review describes current clinical data linking PTSD to cardiovascular disease, via inflammation, autonomic dysfunction, and the renin-angiotensin system. Recent clinical and preclinical evidence regarding the role of the renin-angiotensin system in the extinction of fear memory and relevance in PTSD-related immune and autonomic dysfunction is also addressed.

Blood Pressure Dipping and Urban Stressors in Young Adult African Americans.

BACKGROUND: Blunted nocturnal blood pressure (BP) dipping is an early marker of cardiovascular risk that is prevalent among African Americans. PURPOSE: We evaluated relationships of BP dipping to neighborhood and posttraumatic stress and sleep in urban residing young adult African Americans. METHODS: One hundred thirty-six black, predominately African American, men and women with a mean age of 22.9 years (SD = 4.6) filled out surveys and were interviewed and had two, 24-h ambulatory BP recordings. RESULTS: Thirty-eight percent had BP dipping ratios < .10. Wake after sleep onset (WASO), neighborhood disorder and neighborhood poverty rates but not posttraumatic stress symptoms, and other sleep measures correlated significantly with dipping ratios. Models with the neighborhood measures that also included WASO increased the explained variance. CONCLUSIONS: Studies elucidating mechanisms underlying effects of neighborhoods on BP dipping and the role of disrupted sleep, and how they can be mitigated are important directions for future research.

Nocturnal autonomic balance and sleep in PTSD and resilience.

Posttraumatic stress disorder (PTSD) has been associated with heightened nocturnal autonomic nervous system (ANS) arousal and sleep disturbances. It has been suggested that relationships between sleep and nocturnal ANS activity are influenced by insomnia; however, investigation of this relationship has been limited in PTSD. This study examined nocturnal ANS activity and its relationship to sleep in PTSD and resilience. Physically healthy young adult African Americans with current PTSD (n = 20) or who had never had PTSD despite exposure to a high-impact traumatic event (resilient, n = 18) were monitored with ambulatory electrocardiograms and actigraphy for 24-hr periods. Frequency-domain heart-rate variability measures, that is, low-frequency to high-frequency ratios (LF/HF), which index sympathetic nervous system activity, and normalized HF (nHF), which indexes parasympathetic nervous system activity were examined. Normalized HF during the time-in-bed period was lower for those with PTSD than those with resilience (p = .041). Total sleep time was strongly correlated with time-in-bed LF/HF (r = -.72) and nHF (r = .75) in the resilient group, but these were not correlated in the PTSD group. The results suggest elevated nocturnal ANS arousal and dissociation between ANS activity and total sleep time in PTSD.

Awake/sleep cortisol levels and the development of posttraumatic stress disorder in injury patients with peritraumatic dissociation.

Differences in the time of day that cortisol is sampled and failure to consider the impact of peritraumatic dissociation have been hypothesized as factors possibly contributing to the inconsistent findings in research examining associations between cortisol levels soon after trauma exposure and the subsequent development of posttraumatic stress disorder (PTSD). The present study examined associations between urinary cortisol levels during wake and sleep times soon after a serious injury and the subsequent development of PTSD in adult patients reporting low or high peritraumatic dissociative (PD) symptoms. Thirty-nine injury patients (20 with high and 19 with low PD symptoms) provided a 15-hour (6 PM to 9 AM) urine sample at 3-weeks post-injury and completed the Clinician Administered PTSD Scale at a 7-week follow-up. Participants collected their urine during wake and sleep times separately. Results showed that in the total sample and in the high PD group, wake, but not sleep, cortisol levels were lower in patients who developed PTSD compared to those who did not. A multiple linear regression analysis revealed a significant main effect of PD and a non-significant interaction between wake cortisol and PD in predicting PTSD symptom severity. In addition, results showed that PD was a better predictor of PTSD symptom severity than wake cortisol levels. These results were consistent with prior research indicating lower afternoon/evening cortisol levels in PTSD and strong associations between PD and PTSD, but did not support the existence of subgroups of PTSD patients (dissociators versus non-dissociators) who may differ in basal cortisol levels.

A relationship between REM sleep measures and the duration of posttraumatic stress disorder in a young adult urban minority population.

STUDY OBJECTIVE: To determine relationships of polysomnographic (PSG) measures with posttraumatic stress disorder (PTSD) in a young adult, urban African American population. DESIGN: Cross-sectional, clinical and laboratory evaluation. SETTING: Community recruitment, evaluation in the clinical research unit of an urban University hospital. PARTICIPANTS: Participants (n = 145) were Black, 59.3% female, with a mean age of 23.1 y (SD = 4.8). One hundred twenty-one participants (83.4%) met criteria for trauma exposure, the most common being nonsexual violence. Thirty-nine participants (26.9%) met full (n = 19) or subthreshold criteria (n = 20) for current PTSD, 41 (28.3%) had met lifetime PTSD criteria and were recovered, and 65 (45%) were negative for PTSD. MEASUREMENTS AND RESULTS: Evaluations included the Clinician Administered PTSD Scale (CAPS) and 2 consecutive nights of overnight PSG. Analysis of variance did not reveal differences in measures of sleep duration and maintenance, percentage of sleep stages, and the latency to and duration of uninterrupted segments of rapid eye movement (REM) sleep by study group. There were significant relationships between the duration of PTSD and REM sleep percentage (r = 0.53, P = 0.001), REM segment length (r = 0.43, P = 0.006), and REM sleep latency (r = -0.34, P < 0.03) among those with current PTSD that persisted when removing cases with, or controlling for, depression. CONCLUSIONS: The findings are consistent with observations in the literature of fragmented and reduced REM sleep with posttraumatic stress disorder (PTSD) relatively proximate to trauma exposure and nondisrupted or increased REM sleep with chronic PTSD. CITATION: Mellman TA, Kobayashi I, Lavela J, Wilson B, Hall Brown TS. A relationship between REM sleep measures and the duration of posttraumatic stress disorder in a young adult urban minority population.

Theta frequency activity during rapid eye movement (REM) sleep is greater in people with resilience versus PTSD.

Emotional memory consolidation has been associated with rapid eye movement (REM) sleep, and recent evidence suggests that increased electroencephalogram spectral power in the theta (4-8 Hz) frequency range indexes this activity. REM sleep has been implicated in posttraumatic stress disorder (PTSD) as well as in emotional adaption. In this cross-sectional study, thirty young healthy African American adults with trauma exposure were assessed for PTSD status using the Clinician Administered PTSD Scale. Two consecutive night polysomnographic (PSG) recordings were performed and data scored for sleep stages. Quantitative electroencephalographic spectral analysis was used to measure theta frequency components sampled from REM sleep periods of the second-night PSG recordings. Our objective was to compare relative theta power between trauma-exposed participants who were either resilient or had developed PTSD. Results indicated higher right prefrontal theta power during the first and last REM periods in resilient participants compared with participants with PTSD. Right hemisphere prefrontal theta power during REM sleep may serve as a biomarker of the capacity for adaptive emotional memory processing among trauma-exposed individuals.

Validation of the Fear of Sleep Inventory (FOSI) in an urban young adult African American sample.

The Fear of Sleep Inventory (FOSI) was developed to identify factors that contribute to sleep disturbances in individuals exposed to trauma. This investigation examined the psychometric properties of the FOSI in a sample of African American young adults residing in urban areas. A 5-factor structure was derived from an exploratory factor analysis and then verified by confirmatory factor analysis. FOSI factors were positively correlated with the severity of PTSD (rs = .30 to .58, all ps < .001) and insomnia symptoms (rs = .36 to .64, all ps < .001). Individuals with probable PTSD or insomnia had higher scores on the total FOSI and each of the factors compared to those without probable PTSD (all ps < .001; effect sizes: r = .32 to .62) or insomnia (all ps < .001; effect sizes: r = .42 to .70). These data expand the evidence that the FOSI identifies factors contributing to sleep disturbances in trauma-exposed individuals.