DEMOGRAPHIC PROFILE, SUBSTANCE USE TRENDS AND ASSOCIATED PSYCHOTIC DISORDERS AMONG VETERANS WITH MENTAL HEALTH CONDITIONS: A RETROSPECTIVE COHORT STUDY OF US VETERANS Background: Amphetamine and other substances induced psychotic disorder and associated suicidal risk among hospitalized US veterans is not clear. Aims: To understand the demographic profile, substance use trends, psychotic disorders and suicide attempts in veterans hospitalized with acute Mental Health Conditions (MHC). Methods: Veterans Affairs Informatics and Computing Infrastructure Database (ICD) and codes were used to identify veterans hospitalized with MHC diagnosis between 1999 and 2022. Laboratory records used to determine types of substances used hospitalization frequency, all-cause mortality, suicide attempts and suicide outcomes. SAS was used for statistical analysis. Results: Among veterans with MHC, psychosis, manic-bipolar and PTSD were common diagnosis. Psychosis was comparatively less among males above 50 years of age, but prevalent among Hispanics. In general, substances use was significantly higher, and amphetamines were most used, followed by cannabis codeine, morphine, cocaine, barbiturates, fentanyl, and PCP among veterans with MHC. Amphetamine induced psychotic disorder persisted in 22.28% and other substance induced psychotic disorder persisted in 77.72% of veterans hospitalized with MHC. Psychosis was associated with higher rates of hospitalization, suicide attempts, and suicide death. Conclusions: Among US Veterans with MHC, amphetamine was most used substance associated with higher rates of psychotic disorders, hospitalization, suicide attempts, and death. ASEAN Journal of Psychiatry, Vol. 25 (7) July, 2024; 1-11.