Associations between sleep health, negative reinforcement learning, and alcohol use among South Florida college students with elevated internalizing symptoms.

Negative reinforcement is proposed to mediate associations between sleep and alcohol use, especially among people with depression and/or anxiety symptoms. Worse sleep (e.g., shorter duration, less efficiency, more irregular timing) exacerbates negative emotions, which alcohol may temporarily relieve. Not yet examined, we propose sleep indirectly impacts early stages of alcohol use via differences in negative reinforcement learning (NRL), since sleep impacts emotion, reward response, and learning. The current study aimed to replicate associations between sleep and alcohol use, test associations with NRL, and examine indirect associations between sleep health and alcohol use via NRL among 60 underage college students (ages 18-20 years, 77% female) varying in depression and anxiety symptoms. Participants wore Fitbit smartwatches and completed daily diaries measuring sleep and substance use for ∼14 days before completing two computer tasks assessing social (SNRL) and monetary (MNRL) negative reinforcement learning. Robust generalized linear models tested direct associations within the proposed model. SNRL performance was positively associated with alcohol use, but no other associations were observed. Statistical mediation models failed to indicate indirect effects of sleep on alcohol use via SNRL or MNRL performance. Post-hoc exploratory models examining depression and anxiety symptoms as moderators of direct associations indicated several interactions. Positive associations between sleep timing variability and alcohol use were weakened at higher anxiety symptom severity and stronger at higher depression symptom severity. The positive association between SNRL performance and alcohol use was also stronger at higher depression symptom severity. Among students with elevated depression symptoms, variable sleep timing and stronger SNRL performance were independently associated with more alcohol use, but indirect effects were not supported. Future research should replicate findings, confirm causality of interactions, and examine sleep timing and behavioral responses to negative social stimuli as targets for improving alcohol-related outcomes among underage college students with elevated depressive symptoms.

Sleep fails to depotentiate amygdala-reactivity to negative emotional stimuli in youth with elevated symptoms of anxiety.

Sleep-related problems often precede escalating anxiety in early adolescence. Pushing beyond broad sleep-mental health associations and toward mechanistic theories of their interplay can inform etiological models of psychopathology. Recent studies suggest that sleep depotentiates neural (e.g., amygdala) reactivity during reexposure to negative emotional stimuli in adults. Persistent amygdala reactivity to negative experiences and poor sleep characterize anxiety, particularly at the transition to adolescence. We propose that sleep depotentiates amygdala reactivity in youth but fails to do so among youth with anxiety. Participants (n = 34; 18 males; age, mean [M] = 11.35, standard deviation [SD] = 2.00) recruited from the community and specialty anxiety clinics viewed valenced images (positive, negative, and neutral) across two fMRI sessions (Study, Test), separated by a 10-12-hour retention period of sleep or wake (randomized). Mixed linear models regressed basolateral amygdala (BLA) activation and BLA-medial prefrontal cortex (mPFC) functional connectivity to negative images on Time, Condition, and Anxiety Severity. There were greater reductions in BLA activations to negative target images from Study to Test in the Sleep Condition, which was blunted with higher anxiety (b = -0.065, z = -2.355, p = 0.019). No such sleep- or anxiety-related effects were observed for BLA-mPFC functional connectivity (ps > 0.05). Sleep supports depotentiation of amygdala reactivity to negative stimuli in youth, but this effect is blunted at higher levels of anxiety. Disruptions in sleep-related affective habituation may be a critical, modifiable driver of anxiety.

More time awake after sleep onset is linked to reduced ventral striatum response to rewards in youth with anxiety.

BACKGROUND: Poor sleep and anxiety disorders are highly comorbid in youth, and each predicts altered ventral striatum (VS) response to rewards, which may impact mental health risk. Contrasting evidence suggests previously reported negative associations between sleep health and VS response may be stronger or weaker in youth with anxiety, indicating sensitivity to win/loss information or blunted reward processing, respectively. We cross-sectionally examined the role of sleep in VS response to rewards among youth with anxiety versus a no-psychiatric-diagnosis comparison (ND) group. We expected a group*sleep interaction on VS response to rewards but did not hypothesize directionality. METHODS: As part of the pretreatment battery for a randomized clinical trial, 74 youth with anxiety and 31 ND youth (ages 9-14 years; n = 55 female) completed a monetary reward task during fMRI. During the same pretreatment window, actigraphy and diary-estimated sleep were collected over 5 days, and participants and their parents each reported participants' total sleep problems. We examined group*sleep interactions on VS response to monetary rewards versus losses via three mixed linear models corresponding to actigraphy, diary, and questionnaires, respectively. RESULTS: Each model indicated group*sleep interactions on VS response to rewards. Actigraphy and diary-estimated time awake after sleep onset predicted reduced VS response in youth with anxiety but not ND youth. Parent-reported sleep problems similarly interacted with group, but simple slopes were nonsignificant. CONCLUSIONS: Wake after sleep onset was associated with blunted reward response in youth with anxiety. These data suggest a potential pathway through which sleep could contribute to perturbed reward function and reward-related psychopathology (e.g., depression) in youth with anxiety.