Four new medical conditions could eventually qualify under Arizona's medical-marijuana program.

State health officials are considering whether to add depression, anxiety, post-traumatic stress disorder and migraines as "debilitating conditions," which would allow people to legally use medical pot.

Arizona would become the only state in the nation to allow medical marijuana for anxiety and depression, said Will Humble, director of the state Department of Health Services, which oversees the medical-marijuana program.

He said New Mexico is the only state that actively allows medical pot for post-traumatic stress disorder.

The voter-approved Arizona Medical Marijuana Act requires the state health department to periodically accept and evaluate petitions to allow new medical conditions into the program.

"At this point, it's just a hearing process -- it doesn't mean we're approving these," Humble said. "Our medical-review team thought they had at least provided enough evidence to warrant a hearing (on the four conditions), but that's very different from an approval."

Health officials received numerous petitions from people who suffer from the conditions proposed, as well as people who care for those who have the conditions, said Laura Oxley, a spokeswoman for the health department.

The health department is conducting an online survey to allow public comment. On May 25, the department will hold a hearing on the proposal.

Ultimately, Humble will decide whether or not to add the conditions, he said.

His decision can be appealed through a judicial review.

To add a medical condition, Humble said, petitioners must prove that symptoms impair daily life, submit evidence that medical pot will provide relief, and provide recent articles published in peer-reviewed scientific journals that show marijuana helps treat the conditions, among other things.

Humble said that if PTSD is added to the medical-marijuana program, he predicts it alone could add 15,000 to 20,000 new patients.

Voters created Arizona's medical-marijuana program in 2010 after passing a measure to allow people with certain debilitating medical conditions to use pot.

They must register with the state, which issues identification cards to qualified patients and caregivers.

The state will set up and regulate up to 126 dispensaries. Health officials will accept dispensary applications May 14 through May 25.

More than 22,200 people have received permission to smoke, eat or otherwise ingest medical marijuana to ease their ailments.

Of those, nearly three-quarters are men, and nearly 85 percent of all patients have requested to grow their own cannabis.

Officials denied nine applications.

People ages 31 to 50 make up the largest group of patients using the drug to counter illness, representing 40 percent of all medical-marijuana users.

Those 51 to 81 account for more than 35 percent of patients, while people 18 to 30 make up about 25 percent. People younger than 18 represent less than 1 percent.

The overwhelming majority of medical-pot users reported chronic pain as their medical condition, while muscle spasms also were high on the list, health officials reported.

Other ailments include hepatitis C, cancer and seizures.