Catholic leaders are urging their congregations to reject Proposition 64, the Adult Use of Marijuana Act, which would allow adults 21 years of age or older to legally grow, possess and use marijuana for recreational purposes. The initiative will appear on the Nov. 8 ballot.

Father Gerald Coleman, P.S.S., says the initiative “should be rejected on both humane and moral grounds.” Father Coleman is an adjunct professor of ethics in the Graduate Program of Pastoral Studies at Santa Clara University. He has published and lectured extensively on bioethics questions. 

The negative effects of the drug are still being studied, but a clinical psychologist at Duke University found that people who began using marijuana earlier in life and used it frequently over the years showed an average decline of eight IQ points by the time they turned 38. In addition, numerous studies have linked marijuana with schizophrenia, says Father Coleman.

On a moral level, he notes that Catholic morality is against activities that undermine or degrade our rational capacities. Marijuana can induce delusions or hallucinations, while diminishing the use of a person’s full reasoning abilities.

To date, four states and the District of Columbia have legalized marijuana for recreational use.