Das, PritakshiAvinash, Priya RanjanSaxena, VrindaSinha, Jitendra Kumar2023-08-092023-08-092021-03Das Pritakshi, Avinash Priya Ranjan, Saxena Vrinda, Sinha Jitendra Kumar. COVID-19: The Impact of Social Isolation on Mood, Behavior and Biological Rhythms. Indian Journal of Mental Health. 2021 Mar; 8(1): 96-1032394-66522394-4579http://imsear.searo.who.int/handle/123456789/222729Background: A new strain of Corona virus, SARS- CoV-2, emerged in the Wuhan city of China in December 2019. Due to fast and easy transmission of this respiratory virus the world was under a lockdown for a long time. The purpose of this study was to find out changes in behavior, mood and biological rhythm of people as a result of social distancing and isolation during the COVID-19 pandemic. Methodology: The study was conducted in the months of April and May 2020. This was the time when the lockdown was at its peak. It used a self-rating web based structured questionnaire formulated on Google forms which was circulated through different platforms for people to fill after giving their consents. Results: Highest numbers of respondents were from India (30.2%), USA (21.5%) and UK (11.5%). Our results showed that 46.3% subjects experienced an increase in problems related to sleep. Even though they were getting sufficient amounts of sleep, it was unstructured, and the quality of sleep was affected. The appetite was seen to be good with 68.2% reporting no changes. There was an increase in substance use in 43.8% of the participants while in the lockdown. Our study revealed that 34.2% participants had anxiety and 15.2% showed depressive symptoms. More than 50% respondent’s perceived lack of motivation, lack of energy, nervousness and irritability, and 13.4% reported having suicidal thoughts regularly. Conclusions: This data shows that social isolation due to the COVID-19 lockdown has caused significant changes in the mood, behavior and biological rhythm of people.moodsleepbehaviorbiological rhythmCOVID-19Journal ArticleIndiaAmity University, NoidaAssociate Professor, Department of Psychiatry, Swami Rama Himalayan University Dehradun, UttarakhandSwami Rama Himalayan University, DehradunAmity University, Noida