Trauma is a risk factor for early-onset (EOP) and adult-onset (AOP) psychosis and is also associated with other psychiatric diagnoses and poorer fputcomes in the general population. We examined (1) whether trauma effects are specific to psychosis and (2) whether these effects differ between EOP and AOP.Linear regression models evaluated trauma exposure in two samples (EOP: 647 cases, 694 controls; AOP: 162 cases, 230 controls) as a function of psychotic and nonpsychotic psychiatric diagnosis (NPD) status. Parallel models assessed associations between trauma and symptom severity, global functioning, and cognition. Relative to individuals without psychiatric disorders, participants with psychosis and comorbid NPDs reported the greatest trauma exposure (EOP: β = 0.95; AOP: β = 1.1), followed by those with psychosis only (EOP: β = 0.67; AOP: β = 0.41) and NPDs only (EOP: β = 0.47; AOP: β = 0.36). Greater numbers of NPDs were associated with higher trauma exposure regardless of psychosis status (EOP: β = 0.15; AOP: β = 0.24). Trauma was associated with greater symptom severity (EOP: β = 0.13; AOP: β = 0.14) and poorer global functioning (EOP: β = −0.21; AOP: β = −0.13), but not cognition. No psychosis-by-trauma interactions were observed.Psychosis-specific effects were limited to greater trauma exposure, while trauma-related impacts on outcomes were similar across diagnostic groups. Findings were consistent across EOP and AOP. Results highlight the need for trauma-informed care in psychiatry given broad effects that influence disease course and prognosis.