en Cognitive Neuroscience Cognitive Neuroscience Original Original <div style="text-align: justify;"><strong>Introduction</strong>: Shift workers usually undergo circadian misalignment, which appears when the feeding and sleep-wake cycles are desynchronized with the temporal framework organized by the internal biological&nbsp;clock. People differ considerably&nbsp;in their tolerance to shift work depending on their chronotype. This research aimed to obtain information about circadian disorders and chronotype (as a mediating variable) on consequent mental states such as impulsivity, depression, anxiety, stress, addiction potential, and boredom in students of a medical university in northeastern Iran. We studied the mental state of individuals with circadian misalignment and compared it with the healthy control group.<br> <strong>Methods</strong>: The study design is a double-blind, randomized, controlled clinical trial. Thirty-five participants were randomly assigned to circadian alignment/misalignment protocols. Subjects completed questionnaires as baseline data (pre-test) and the end of the interventions (post-test). The study instruments were the multidimensional state boredom scale (MSBS), addiction potential scale, depression, anxiety, and stress scale-21, and Barratt impulsiveness-11 (BIS-11). To analyze outcomes, we categorized participants based on chronotype as mediate variable within each group (circadian aligned and misaligned condition).<br> <strong>Results</strong>: The mean age of the participants was 21.66 years (range: 18-25 years). One-way analysis of variance to compare research variables in groups based on chronotype (evening, intermediate type, and morning types) showed a significant difference between the three chronotype groups in the total and non-planning impulsivity, as well as active and passive addiction potential (P<0.001). The Bonferroni post hoc test was used to compare the mean of variables in the chronotype groups about total and non-planning impulsivity scores, as well as active and passive addiction. The results showed that non-planning (P<0.01) and active addiction (P<0.001) in people with evening and intermediate types were significantly lower than in people with morning type (P=0.02).<br> <strong>Conclusion</strong>: Alterations in diurnal profiles of activity, sleep, and feeding time, based on chronotype related to impulsiveness and boredom, and such circadian misalignment were associated with addiction potential.</div> Anxiety, Circadian rhythm, Depression, Stress disorders, Substance-related disorders, Chronobiology, Boredom 219 232 http://bcn.iums.ac.ir/browse.php?a_code=A-10-1425-6&slc_lang=en&sid=1 Mohammad Niroumand Sarvandani m.niroumand@live.com 13700319475328460052159 13700319475328460052159 No Student Research Committee, School of Medicine, Shahroud University of Medical Sciences, Shahroud, Iran. Behzad Garmabi behzad.garmabi@gmail.com 13700319475328460052160 13700319475328460052160 No School of Medicine, Shahroud University of Medical Sciences, Shahroud, Iran. Masoud Asadi m-asadi@arak.ac.ir 13700319475328460052161 13700319475328460052161 No Department of Psychology, Faculty of Humanities, Arak University, Arak, Iran. Hamed Ghazvini hghazvini1@gmail.com 13700319475328460052162 13700319475328460052162 No Psychiatry and Behavioral Sciences Research Center, Addiction Institute, Mazandaran University of Medical Sciences, Sari, Iran. Raheleh Rafaiee rahelerafaie@gmail.com 13700319475328460052163 13700319475328460052163 No Department of Neuroscience, School of Advanced Technologies in Medicine, Mazandaran University of Medical Sciences, Sari, Iran. Hamid Kalalian Moghaddam h.kalalian@shmu.ac.ir 13700319475328460052164 13700319475328460052164 Yes Department of Addiction Studies, School of Medicine, Shahroud University of Medical Sciences, Shahroud, Iran.