An altered neural response to reward may contribute to alcohol problems among late adolescents with an evening chronotype

Abstract

Evening chronotypes not only differ from morning-types in their sleep and circadian timing, but they are prone to problematic outcomes involving reward function, including affective disturbance, sensation seeking, and substance involvement. We explored the neural mechanisms underlying these chronotype differences by comparing the neural response to reward in morning- and evening-types. Using a monetary reward fMRI paradigm, we compared the neural response to reward in 13 morning-types and 21 evening-types (all 20 y/o males). Region-of-interest (ROI) analyses focused on the medial prefrontal cortex (mPFC) and ventral striatum (VS), comparing the chronotype groups in these ROIs during anticipation and outcome conditions, and adjusting for time of scan. Chronotype groups were also compared on measures of sensation-seeking, substance involvement, and sleep quality. Evening-types reported significantly greater levels of alcohol dependence and worse sleep quality. Furthermore, evening-types showed an altered neural response to reward relative to morning-types, specifically, reduced mPFC reactivity during reward anticipation and increased VS reactivity during win outcome. In turn, less activation in the mPFC region in response to reward was associated with greater alcohol consumption, while increased activation in the VS in response to reward was associated with more symptoms of alcohol dependence. Increased reward-related problems among evening-types may be accompanied by altered neural responses to reward.

Circadian disruption: New clinical perspective of disease pathology and basis for chronotherapeutic intervention

“…Kohyama (2009Kohyama ( , 2011 terms this condition asynchronization, which in principle is equivalent to circadian disruption. Finally, eveningness in young adults is linked to risk for excess alcohol consumption and addiction (Adan, 1994;Hasler et al, 2012Hasler et al, , 2013Hasler et al, , 2015Wittmann et al, 2010). As discussed earlier, routine alcohol consumption, itself, may cause CD.…”

Examining racial/ethnic disparities in the association between adolescent sleep and alcohol or marijuana use

“…Nevertheless, findings are consistent with a growing body of longitudinal data suggesting that sleep problems predict the onset of subsequent alcohol and other drug use and disorders in teens and young adults (14, 16). Moreover, data from neuroimaging studies provides solid mechanistic evidence that sleep and circadian disruptions may be causally related to the development and exacerbation of alcohol and other drug use disorders (39). An additional limitation is the reliance on self-reported sleep and AM use, which may have introduced bias or common method variance.…”

Sleep quality, sleep habits, and chronotypes of medical interns at the beginning of their training

“…Evening chronotype individuals have longer sleep duration, 23 less time in bed during the weekdays but more during the weekends, 23 irregular sleep-wake cycles, 23,24 and a higher prevalence of insomnia. 25 In addition to its effects on sleep, the evening chronotype is associated with a higher consumption of caffeinated drinks, 24 sleeping pills, 24 alcohol, 26,27 and stimulants. 26,27 Furthermore, anxiety, 28 depression, 28 dysfunctional attitudes toward work, 29 poor academic performance, 29 and poor quality of life 30 have been associated with the evening chronotype.…”

“…25 In addition to its effects on sleep, the evening chronotype is associated with a higher consumption of caffeinated drinks, 24 sleeping pills, 24 alcohol, 26,27 and stimulants. 26,27 Furthermore, anxiety, 28 depression, 28 dysfunctional attitudes toward work, 29 poor academic performance, 29 and poor quality of life 30 have been associated with the evening chronotype.…”