Sleep Spindles Favor Emotion Regulation Over Memory Consolidation of Stressors in Posttraumatic Stress Disorder

BACKGROUND

Posttraumatic stress disorder (PTSD) is a trauma-induced condition, characterized by intrusive memories and trauma-associated anxiety. Non-rapid eye movement (NREM) sleep spindles might play a crucial role in learning and consolidating declarative stressor information. However, sleep and possibly sleep spindles are also known to regulate anxiety, suggestive of a dual role for sleep spindles in the processing of stressors. Specifically, in individuals with high PTSD symptom burden, spindles might fail to regulate anxiety levels after exposure and instead might maladaptively consolidate stressor information.

METHODS

To disentangle the role of spindles in declarative memory versus anxiety regulation after stressor exposure and to examine the role of PTSD in these processes, we measured nap sleep after a cohort of 45 trauma-exposed participants were exposed to laboratory stress. Participants (high vs. low PTSD symptoms) completed 2 visits: a stress visit involving exposure to negatively valent images before nap and a control visit. In both visits, sleep was monitored via electroencephalography. A stressor recall session occurred after the nap in the stress visit.

RESULTS

Stage 2 NREM (NREM2) spindle rates were higher in stress versus control sleep, indicative of stress-induced changes in spindles. In participants with high PTSD symptoms, NREM2 spindle rates in stress sleep predicted poorer recall accuracy of stressor images relative to participants with low PTSD symptoms, while correlating with greater reduction in stressor-induced anxiety levels after sleep.

CONCLUSIONS

Contrary to our expectations, although spindles are known to play a role in declarative memory processes, our findings highlight an important role for spindles in sleep-dependent anxiety regulation in PTSD.

Explicit and implicit bias among parents of sexual and gender minority youth

Sexual and gender minority (SGM) youth are at disproportionate risk for poor mental health outcomes, in part due to experiences and expectations of anti-SGM bias including from their own parents. We examined explicit anti-SGM and implicit antisexual minority bias in parents of SGM youth and associations with parenting and parent and youth psychosocial functioning. Heterosexual/cisgender parents (N = 205, M_age = 46.9 years, SD = 8.5) of SGM youth (≤ 29 years old, M_age = 19.4, SD = 4.7) completed an online study including measures of explicit anti-SGM and implicit anti-SM bias, parental acceptance and psychological control, parent-child unfinished business (unresolved negative feelings related to their child's identity), parental depression and anxiety, and youth anxiety, depression, substance use, and exposure to bullying. In models including both explicit anti-SGM and implicit anti-SM bias as predictors of parent and youth outcomes, explicit bias was uniquely associated with lower parental acceptance and greater parental psychological control, parent-child unfinished business, parental anxiety and depression, and youth substance use and exposure to bullying, whereas implicit bias was uniquely associated with greater parent-child unfinished business and parental depression. Further, the combination of high levels of both explicit and implicit bias was associated with the highest levels of parent-child unfinished business, parental depression, and youth anxiety, depression, and exposure to bullying. Results suggest that both types of bias jointly contribute to parenting and parent and youth psychosocial functioning and can help identify families at greatest risk for maladjustment. Findings can inform the development of interventions designed to reduce anti-SGM bias in parents of SGM youth. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The Relationship of Fear-Potentiated Startle and Polysomnography-Measured Sleep in Trauma-Exposed Men and Women with and without PTSD: Testing REM Sleep Effects and Exploring the Roles of an Integrative Measure of Sleep, PTSD Symptoms, and Biological Sex

STUDY OBJECTIVES

Published research indicates that sleep is involved in emotional information processing. Using a fear-potentiated startle (FPS) and nap sleep protocol, we examined the relationship of emotional learning with REM sleep (REMS) in trauma-exposed participants. We also explored the roles of PTSD symptoms, biological sex, and an integrative measure of polysomnography-measured (PSG) sleep in the learning-sleep relationship.

METHODS

After an adaptation nap, participants (N=46) completed 2 more visits (counterbalanced): a stress-condition visit, which included FPS conditioning procedures prior to a nap and assessment of learning retention and fear extinction training after the nap, and a control visit, which included a nap opportunity without stressful procedures. FPS conditioning included a "fear" visual stimulus paired with an air blast to the neck and a "safety" visual stimulus never paired with an air blast. Retention and extinction involved presentation of the visual stimuli without the air blast. Primary analyses examined the relationship between FPS responses pre- and post- sleep with stress-condition REMS duration, controlling for control-nap REMS duration.

RESULTS

Higher safety learning predicted increased REMS and increased REMS predicted more rapid extinction learning. Similar relationships were observed with an integrative PSG sleep measure. They also showed unexpected effects of PTSD symptoms on learning and showed biological sex effects on learning-sleep relationships.

CONCLUSIONS

Findings support evidence of a relationship between adaptive emotional learning and REMS. They underscore the importance of examining sex effects in sleep-learning relationships. They introduce an integrative PSG sleep measure with potential relevance to studies of sleep and subjective and biological outcomes.

1074 Fear Reactivity And Sleep In Trauma-Exposed Males And Females With And Without PTSD

Introduction

Sleep disturbance is considered central to mechanisms of PTSD development and maintenance, and fear learning protocols have been used as laboratory models to understand PTSD disease mechanisms. Some research indicates that fear learning may influence subsequent sleep, especially REM sleep, and that sleep may influence subsequent extinction. In this study, we examined the relationship of startle reactivity during conditioning and later extinction with objectively-measured sleep in PTSD-positive and negative subjects.

Methods

These analyses were performed as part of a larger study of PTSD and sleep. Thirty-four (34) trauma-exposed male and female participants with and without PTSD completed a fear-potentiated startle conditioning procedure at 9:45am, followed by a PSG-monitored nap (13:30-15:30), followed by an extinction protocol at 4:30pm. All visits were preceded by an adaptation nap visit at least 7 days prior. Eye-blink EMG was used to measure startle reactivity. Mixed-model analyses were performed in SPSS.

Results

PTSD-positive subjects had higher REM sleep duration (p<.05) and a trend towards shorter REM sleep latency (p=.06). There were no other group or sex effects on standard PSG sleep parameters. During conditioning, PTSD-positive status was associated with higher startle reactivity across stimulus types (p<.01), driven by increased reactivity in PTSD-positive vs. PTSD-negative females. A PTSD x sex interaction effect on startle reactivity showed the opposite effect in males (p<.01). Higher startle reactivity during conditioning predicted longer sleep latency during the subsequent nap (p<.05), but reactivity during conditioning and extinction did not otherwise show a relationship to standard PSG sleep measures.

Conclusion

These findings are consistent with previous research indicating REM sleep abnormalities as well as heightened fear responses in PTSD. While the observed relationship between higher startle and longer sleep latency is consistent with studies indicating that stress affects subsequent sleep, further research in larger samples is needed to understand causal mechanisms and to advance our understanding of sleep-PTSD mechanisms.

Support

VA Career Development Award-5IK2CX000871-05