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140 Word count of text: 4279Number of tables/figures: 2 3 Abstract Purpose: To test whether the association between childhood adversity and positive and negative psychotic experiences is due to genetic confounding. Method:Childhood adversity and psychotic experiences were assessed in a sample of 226 twins from the general population. A monozygotic (MZ) twin differences approach was used to assess possible genetic confounding. Results:In the whole sample, childhood adversity was significantly associated with positive (β =.45; SE=.16; p=.008) and negative psychotic experiences (β=.77; SE=.18; p<.01). Within-pair MZ twin differences in exposure to childhood adversity were significantly associated with differences in positive (β =.71; SE=.29; p=.016) and negative psychotic experiences (β =.98; SE=.38; p=.014) in a subsample of 86 MZ twin pairs.Conclusions: Individuals exposed to childhood adversity are more likely to report psychotic experiences. Furthermore, our findings indicate that unique environmental effects of childhood adversity contribute to the development of psychotic experiences.