Objectives:
Assessment of the association between weight gain in patients with first-episode psychosis (FEP) and biopsychosocial and sociological factors.

Methods:
25 subjects with FEP aged 14–35 examined in week 1 (P1) and after three months of hospitalization (P3) were enrolled in the study. Within 3 months all patients were diagnosed with schizophrenia. The study used: a socio-demographic survey, Positive and Negative Syndrome Scale (PANSS), State-Trait Anxiety Inventory (STAI), Coping Inventory for Stressful Situations (CISS), Questionnaire Eating Behaviors (QEB), and routine biochemical test findings. For some variables, the differences (variable_D) between the values at P1 and P3 were calculated.

Results:
Statistically significant correlations were shown between body weight_P1, _P3, _D, and healthy diet index_P1, _P3, severity of psychotic symptoms measured by the PANSS_P1 and _D, the CISS focused on emotions and task_P1, _P3 and _D, mother’s body weight in youth and now, father’s body weight in youth and now, and the number of the patient’s siblings. In the linear regression analysis, body weight_P1 and the CISS focused on emotions_P1 turned out to be significant predictors of body weight_P3.

Conclusions:
Multifactorial influence of weight gain in FEP in schizophrenia was observed. Countermeasures against weight gain should refer not only to the diet, but also to the way the eating habits are related to psychopathology associated with psychosis and to the emotional functioning of the patient.