ST. PAUL, Minn. (AP) — Health officials say most Minnesota patients who used medical marijuana during the first year of the state's tightly regulated program reported benefits.

Health Commissioner Dr. Ed Ehlinger says early data show the drug is providing many people with "substantial benefits, minimal side effects and no serious adverse events."

The study released Tuesday is based on survey and other data. The program began July 1, 2015, and the data runs through June 31, 2016.

Patients were asked how much benefit they believe they received from using medical cannabis on a scale from one to seven, with seven meaning a great deal of benefit. Across all patients, 64 percent indicated a benefit rating of six or seven. Nine percent indicated little or no benefit.

The complete study is due out this summer.