Chronic pain is the main reason given by people who enroll in state approved medical marijuana programs.

Then come a stiffness related to multiple sclerosis and nausea related to chemotherapy, according to a 15-state analysis published Monday in the journal Health Affairs.

The study did not determine whether marijuana actually helped anyone with their problems, but the reasons given by the patients correspond to what we know from the science of marijuana. marijuana and its chemical components.

"The majority of patients for whom we have data use cannabis for reasons that science is most powerful," said lead author Kevin Boehnke of the University of Michigan at Ann Arbor .

California became the first state to allow the use of marijuana for medical purposes in 1996. More than 30 states now allow marijuana for dozens of health problems. The lists of conditions allowed vary by state, but in general, a doctor must certify that a patient has an approved diagnosis.

Although the US government has approved drugs based on compounds present in the plant, it considers marijuana illegal and places limits on research. This has led to states allowing certain diseases and symptoms for which rigorous science is lacking. Most of the evidence comes from drug studies based on marijuana ingredients, not from smoked marijuana studies or edible forms.

Dementia and glaucoma, for example, are conditions where marijuana has not been proven, but some states do. Many states allow Parkinson's disease or post-traumatic stress disorder when evidence is limited.

The analysis is based on 2016 data from 15 states that indicated the reasons they had used marijuana. The researchers compared the symptoms and conditions to a comprehensive review of scientific evidence: the 2017 report of the National Academies of Science, Engineering and Medicine.

About 85% of patients' reasons were substantiated by substantial or conclusive evidence from the national academy report.

The study shows that people are discovering the evidence of cannabis and its chemical components, said Ziva Cooper of the Cannabis Research Initiative at the University of California at Los Angeles. Cooper sat on the editorial board of the National Academies' Report, but did not participate in the new study.

The study found that about two-thirds of the 730,000 reasons were related to chronic pain. Patients may report more than one painful condition, so the figure may overestimate the number of patients.

Patients include Brandian Smith, 37, from Pana, Illinois, who qualifies because of her fibromyalgia. The bad days, his muscles have the impression of being tight in a vice. She said that she had stopped taking opioid painkillers because marijuana worked best for her. She spends about $ 300 a month at her marijuana dispensary.

"Cannabis is the first thing I've found that really makes the pain go away and does not leave me so high that I can not enjoy my day," Smith said.

The study also revealed:

Alaska, Colorado, Nevada, and Oregon have experienced a decline in the number of medical marijuana patients after the legalization of marijuana for recreational purposes in these states.

-More than 800,000 patients have been enrolled in medical marijuana programs in 2017 in 19 states. This does not include California and Maine, which do not require patients to enroll. According to other estimates, this figure would be greater than 2 million.

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