A clinico-epidemiologic research method combined with a multi-dimensional analysis was applied in patients suffering from attack-like schizophrenia. This made it possible to distinguish the most informative criteria for a long-term social and work fitness prognosis: premorbid adaptation, age by the disease onset, duration of the initial period, the first remission syndrome, the intensity of negative disturbances occurring in the course of the first remission, duration of the first remission, exogenous injuries in the premorbid and in the pre-manifest++ periods of psychosis. The prognosis classifier developed with regard to the above criteria provides a correct forecasting of the social and work fitness status of patients in 81.19% of cases (when patients are attributed to the favourable prognosis group) and in 69.64% of cases (when patients are attributed to the unfavourable prognosis group).