Background: This study aims to examine adverse childhood experiences (ACEs), its interaction with methamphetamine (METH) use (e.g., frequency, duration, and dependence) and METH-associated risk of psychosis. Methods: This was a cross-sectional study conducted among METH users at a drug rehabilitation center in China. Participants were assessed using Mini International Neuropsychiatric Interview for METH-associated psychosis. Results: Of 189 participants, 50.5% reported at least one of eight ACE categories and 35.4% had past history of a psychotic episode. After adjusting for age, sex, education, and marital status, all ACE categories except emotional abuse and parental separation or divorce increased the risk of ever experiencing METH-associated psychosis. When comparing participants who reported no ACEs, those with three or more ACEs had higher risks of lifetime psychosis (OR = 4.5, 95% CI: 1.6-12.6). Relationship between number of ACEs and lifetime psychosis was graded (p < .01). The interaction between frequency of METH use (>= 4 vs. <4 times/month) and number of ACEs on the risk of METH-associated psychosis was statistically significant (p = 0.02), showing a trend of adjusted OR decreased significantly as the number of ACEs increased. Conclusions: These analyses indicate that childhood adversities increase the individual's vulnerability to METH-associated psychosis. Further larger longitudinal studies are warranted. (C) 2014 Elsevier Ireland Ltd. All rights reserved.