Twenty-Four Hour Rest–Activity Rhythm Disturbances and Neural Alterations Associated With Emotion Regulation in Shift Workers

We examined the neural basis of emotion regulation in shift workers, and the relationships between the neural basis of emotion regulation, mood, sleep disturbance and 24-h rest–activity rhythm (RAR). Fifty-six shift workers (SW) with non-standard shift schedules and 52 controls (CON) participated in this study. They completed self-reported measures of sleep and mood problems, kept a sleep diary, and wore a wrist actigraphy device to assess sleep and 24-h RAR. They underwent one-night polysomnography and were scanned while performing an emotion regulation task. We examined group differences in the neural basis of emotion regulation and correlations between neural, mood, sleep and 24-h RAR variables. SW showed greater sleep disturbance (i.e., lower actigraphy-estimated sleep efficiency) and altered 24-h RAR (e.g., lower actigraphy-estimated interdaily stability) than CON. SW also exhibited increased anterior insula (AI) response to negative pictures (vs. neutral pictures) but reduced activation in the dorsomedial prefrontal cortex (dMPFC) and AI-dMPFC functional connectivity during emotion regulation compared to CON. Shift work was associated with increased motor activity during the most active 10-h period, which then contributed to increased AI response to negative pictures. Our findings suggest that shift work may be associated with the neurobiological alterations of emotion regulation. Furthermore, increased motor activity may serve as a pathway through which shift work could contribute to neurobiological alterations associated with emotional regulation.