The study tested the hypothesis of difference of personality identity in patients with gastroesophageal reflux disease (GERD) and healthy individuals and of association of difference with manifestations of aggressiveness. The sample of 75 subjects includes an experimental group of 45 patients, aged 21 to 38 years old (M=27.85, SD=3.21), with an established diagnosis of GERD, 66.7% men and 33.3% women. Control group of 30 normal individuals aged 21 to 32 years (М=26.90, SD=3.87), who do not have a history of GERD, 66.0% men and 40.0% women. The methodological complex includes: Method for the Study of Personal Identity Schneider (MILES); Questionnaire for Objective Measurement of Status Ego-Identity (adaption by Gavrilova, Glushak); ISTA (Tupitsyn et al.); the method “Types of aggressiveness” (Pochebut); Buss-Durkee Hostility Inventory. The diffuse identity was revealed in 48.9% of patient group, the "moratorium" identity status was revealed in 20.0%, while achieved positive identity, premature identity, and pseudo-positive identity were found in 17.7%, 6.7%, and 6.7% of patients, accordingly. The "moratorium" identity status was revealed in 30.0% of normal group, while achieved positive identity, "moratorium" identity, and pseudo-positive identity were found in 26.6%, 23.3%, and 16.7% of patients, accordingly. Also, in GERD patients following connections with different aggression indicators were revealed depending on the identity status: the status of the adopted identity is directly related to the object aggression; the status of
a moratorium related with the deficit aggression, the status of achieved identity related with the indirect aggression and guilt. Personal identity indicator corresponds to the status of accepted and diffuse identity. It was revealed that the lower state of personal identity indicator connected to the higher state of the irritation and hostility in patients. The control group did not reveal significant links between the indicators of identity and indicators of aggression.