This study aimed to investigate the circumstances, characteristics, and background factors of mental disorders within the information technology (IT) industry, which is known for the frequent occurrence of mental disorders from overwork and poor psychosocial work environment. The study analyzed 238 cases of mental disorders and suicides in the IT industry from fiscal years 2010 to 2018 on the database constructed by the Japan Research Center for Overwork-Related Disorders. The results showed a higher number of cases among men (n=178, 74.8%) and an increasing number among women. The data for diagnosis of mental diseases indicated a high number of depressive episodes (150 cases, 63.0%). Regarding work-induced psychological burden, 37 cases (15.5%) reported "extremely long working hours" for "special events" and 65 cases (27.3%) reported "constantly long working hours". For "specific events", 87 cases (36.6%) reportedly "caused (major) changes in the content and amount of work". Among women, 13 cases (21.7%) of "sexual harassment" (SH), which showed an increasing trend. Therefore, in the IT industry, the working hours must be properly managed. Mental health measures should also accompany improved psychosocial environment in the workplace, and prohibition of SH at work in particular.