A large-scale, long-term study finds that adolescents who frequently use a specific psychoactive substance are significantly more likely to be diagnosed with schizophrenia in early adulthood than those who do not. Based on this finding, which of the following conclusions is the most accurate and nuanced interpretation of the relationship?

A news headline reads: 'Study Proves Marijuana Use Directly Causes Schizophrenia.' Based on the established scientific understanding of the relationship between the two, which of the following statements provides the most accurate evaluation of this headline?