Objective: To study weight change during admission and after being discharged for 1 year as well as risk factors associated with weight gain among patients with schizophrenia in the Inpatient Psychiatry unit at Siriraj Hospital.

Materials and Methods: A retrospective chart review was conducted on patients with schizophrenia who were admitted during 2002 to 2013.

Results: Out of 706 reviewed inpatient charts, 306 admissions met inclusion criteria. The mean of length of stay was 29.1 days (SD 14.9). During admission, an average weight gain was 1.9 kg (SD 2.9) and average increasing body mass index [BMI] was 0.7 kg/m² (SD 1.1). After 1 year follow-up, an average weight gain was 3.6 kg (SD 6.3) and the mean of increasing BMI was 1.4 kg/m² (SD 2.4). The risk factors associated with weight gain included low weight at admission, being young patients, long length of stay, current smokers and treatment naive group.

Conclusion: Patients with schizophrenia were likely to gain weight during psychiatric hospitalization and tend to gain weight further after being discharged for 1 year. There are many factors associated with weight gain during admission. Weight control interventions during hospitalization are crucial for patients at risk.

Keywords: Weight change, Risk factors, Schizophrenia, Inpatient