The House Wednesday gave preliminary approval to a medical marijuana dispensaries bill, endorsing an amendment that calls for a study of potential tax revenue from legalizing and taxing pot.

Another amendment, which would have added post-traumatic stress disorder to the list of conditions that qualify a person to obtain medical marijuana, was withdrawn on the floor. Public Safety Commissioner Keith Flynn, whose agency runs the medical marijuana program, lobbied against it.

Some worried that the amendment for a study of potential revenue that could be gained by taxing and regulating marijuana is a step toward legalization.

Rep. Anne Donahue, R-Northfield, a member of the Human Services Committee, said the amendment does "fatal damage to the underlying bill" because it mixes the question of legalization with that of providing symptom relief.

Rep. Chris Pearson, P-Burlington, said the amendment simply calls for research.

"We’re not down the road. There’s nothing to fear here. We should actually embrace the idea that the Vermont Legislature would look at questions with as much information as possible on the table," Pearson said.

Others said legalization is the goal.

"It is step one because Vermonters want marijuana to be legal," said Rep. Kristina Michelsen, D-Hardwick, whose original proposal for a marijuana study died last month when Speaker Shap Smith ruled it not germane to the bill to which it was attached.

Rep. James Masland, D-Thetford, sponsored, and subsequently withdrew, a floor amendment to add PTSD back into the bill. Veterans as well as civilians who experienced traumatic events resort to illegal means to obtain marijuana to ease their symptoms, he said.

"They’re pleading with me to find a legal means so that they don’t have to go outside the law," he said.