Mobile, Remote, and Individual Focused: Comparing Breath Carbon Monoxide Readings and Abstinence Between Smartphone-Enabled and Stand-Alone Monitors.

INTRODUCTION: Newly available, smartphone-enabled carbon monoxide (CO) monitors are lower in cost than traditional stand-alone monitors and represent a marked advancement for smoking research. New products are promising, but data are needed to compare breath CO readings between smartphone-enabled and stand-alone monitors. The purpose of this study was to (1) determine the agreement between the mobile iCO (Bedfont Scientific Ltd) with two other monitors from the same manufacturer (Micro+ pro and Micro+ basic) and (2) determine optimal, monitor-specific, cotinine-confirmed abstinence cutoff values. METHODS: Adult (≥18) smokers (n = 26) and nonsmokers (n = 21) provided three breath CO samples (using three different monitors) in each of 10 sessions, and urine cotinine was measured for gold standard determination of abstinence. CO comparisons (N = 437) were analyzed using regression-based Bland-Altman Analysis of Agreement; receiver operating characteristics curves were used to determine optimal abstinence cutoffs. RESULTS: Bland-Altman analyses indicated that the iCO monitor provided higher CO results than both Micro+ monitors. Sensitivity and specificity analyses showed that the optimal CO cutoff for determining abstinence was <3 ppm for the Micro+ pro (88% sensitivity, 93% specificity) and Micro+ basic (83% sensitivity, 98% specificity), but was higher for the iCO (<6 ppm; 73% sensitivity, 100% specificity). CONCLUSIONS: Relative to both Micro+ monitors, the smartphone-enabled iCO provided systematically higher CO values and required a higher cutoff to reliably determine smoking abstinence. This does not indicate that CO values obtained using the iCO are not valid; instead, these results suggest that monitor-specific abstinence cutoffs are needed to ensure accurate bioverification of smoking status. IMPLICATIONS: Results from this study indicate that CO values from the smartphone-enabled iCO should not be used interchangeably with the stand-alone Micro+ pro and Micro+ basic, particularly when lower CO values (<10 ppm) are critical (ie, determination of abstinence vs confirming smoking status for study inclusion). Optimal CO cutoffs recommended for determining abstinence on Micro+ and iCO monitors are at <3 and <6 ppm, respectively.

Sleep Disturbance in Posttraumatic Stress Disorder: Epiphenomenon or Causal Factor?

PURPOSE OF REVIEW: The goal of this review is to integrate recent findings on sleep disturbance and PTSD, examine sleep disturbance as a causal factor in the development of PTSD, and identify future directions for research, treatment, and prevention. RECENT FINDINGS: Recent research highlights a relationship between both objective and subjective sleep disturbance and PTSD across diverse samples. Sleep disturbance also predicts PTSD over time. Finally, treatments targeting sleep disturbance lead to decreased PTSD symptoms, while standard PTSD treatments conclude with residual sleep disturbance. Sleep disturbance may be more than a mere epiphenomenon of PTSD. Future research examining the causal role of sleep disturbance in the development of PTSD, as well as the utility of targeting sleep disturbance in prevention and treatment, is necessary to fully understand the likely bidirectional relationship between sleep disturbance and PTSD.

Examining sex, adverse childhood experiences, and oxytocin on neuroendocrine reactivity in smokers.

Adverse childhood experiences (ACE) are associated with greater neuroendocrine responses to social stress in substance users. The neuropeptide oxytocin might attenuate this relationship. Given sex differences in ACE exposure and neuroendocrine stress reactivity, it is unknown whether this association is similar for males and females. Therefore, this secondary analysis evaluated the interactive effect of sex, ACE, and acute oxytocin administration on neuroendocrine stress responses in adult cigarette smokers (N = 144). Participants completed the Adverse Childhood Experiences Questionnaire at screening and were randomized to receive intranasal oxytocin or placebo before undergoing the Trier Social Stress Task (TSST). Cortisol levels were assessed at pre- and post-medication administration and at 20 and 40 min following the TSST. Generalized linear mixed models were developed to predict post-TSST cortisol levels. Predictors included treatment assignment (placebo vs. oxytocin), sex (male vs. female), ACE (0-10 total score), pre-medication cortisol levels, and minutes since medication administration. The hypothesized three-way interaction between sex, oxytocin, and ACE scores was significant. Linear associations between ACE scores and cortisol reactivity indicated higher ACE scores were associated with attenuated cortisol response in females, regardless of treatment condition. For males, higher ACE scores were associated with heightened cortisol response, an effect that was attenuated by oxytocin. Results indicate that the association between ACE and neuroendocrine reactivity to social stress, as well as the attenuating effect of oxytocin, is differentially impacted by sex. Males with greater childhood adversity may be more likely to benefit from oxytocin's anxiolytic properties.