Unprecedented clinical threats always creates abrupt physiological threat along with psychological trauma. COVID-19 pandemic situation has resulted in significant onset of mental stress in global population. The rationale behind the study substantiates the plausible major reasons and effects behind the inception of psychopathological stress in a population due to the COVID-19 pandemic circumstances. The research work is an evidence-based demographic study, conducted through psycho-clinical interviewing of random population during the pandemic (lockdown) in West Bengal, India. The study was designed to produce statistical evidence of mental unwellness due to COVID-19 ambience and understand the brain-behaviour circuit behind the psychopathological condition. Findings strongly indicate the prevalence of psychological instability in adults. The case-study reveals the fact that sudden pandemic outbreak created upsurge in the anxiety-like behavioural patterns along with situational depression, followed by abnormal sleeping patterns. Digital media were the prime source of pandemic-related neurobehavioural stress contents, which eventually resulted in significant expression of psychopathological manifestations which were analysed in terms of behavioural marker exhibitions. However, there were indications of remedial strategies to combat the mental stress in the population. The case-report unravels the fact that apart from the severity of COVID-19 biomedical issues, there were strong traumatic exposition in the global population which was initiated due to the abrupt severity of the disease and also due to the surge of huge negative data of the pandemic. Clinical psychologists are working on novel protocols to fight with future pandemic-related mental illness, which eventually affects the daily lifestyle of a population.