Eight months after the state's first medical marijuana dispensaries opened, 1,017 patients have registered with the state to receive the drug, the Department of Public Safety told lawmakers this week.

A fourth dispensary, Southern Vermont Wellness, is slated to open Tuesday in Brattleboro, officials said. The state's other three dispensaries are in Burlington, Brandon and Montpelier.

A bill in the Senate would add two more dispensaries and allow those businesses to offer home delivery of marijuana.

The bill would also eliminate a statewide cap on the number of registered patients who receive marijuana from a dispensary.

Of the 1,017 patients registered with the state, 642 patients have selected dispensaries, said Francis Aumand, director of the criminal justice services division of the Department of Public Safety.

The other 375 patients grow their own, Aumand said.

The bill, S.247, also increases from two to four ounces the amount of marijuana a dispensary can cultivate and possess per patient. That rule applies to dispensaries that serve more than 14 patients.

Public safety officials, marijuana advocates and dispensaries say they compromised on the bill, sponsored by Sen. Jeanette White, D-Windham, but all support it.

Public safety officials agreed to eliminate the patient cap and add two dispensaries in exchange for striking a proposal to add post-traumatic stress disorder to the list of "debilitating medical conditions" that qualify a person to apply for a registry identification card.

That list now includes cancer, multiple sclerosis, HIV and other conditions.

There needs to be more research about marijuana's efficacy in treating PTSD, according to Aumand. "We want to make sure that it grows at a pace that can be regulated," he said.