Using marijuana between once a week and every day increases the risk of a psychosis-like experience by 159 percent, the U.K. Daily Mail reported, citing a new study.

Researchers from the University of Montreal followed 4,000 13-year-olds for four years, having participants complete questionnaires about substance abuse and any psychotic experiences.

The study was published in the Journal of Child Psychology and Psychiatry, the Daily Mail reported.

 Psychotic experiences are described as perceptual aberration — the feeling that something external is part of the body — and feelings of being unjustly and badly treated.

Other tests included cognitive tests including to assess their IQ, memory and stimuli response.

The researchers were concerned with the negative effects of marijuana on adolescents.

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