ANAHEIM, Calif. — Employers struggling to maintain a drug-free workplace are facing two major challenges: the rash of states legalizing marijuana both recreationally and medically along with the opioid epidemic, according to experts.

Experts urged employers to pay attention to shifting regulations and their employees’ behavior during two separate sessions on Wednesday at the Disability Management Employer Coalition’s annual conference in Anaheim, California.

Eric Meyer, Philadelphia-based partner with Dilworth Paxton L.L.P., told attendees in a session on marijuana in the workplace that one of the top questions from employers and clients relates to accommodating marijuana use among workers.

His answer is the same for most questions: “It depends. It depends. It depends,” Mr. Meyer said.

Mr. Meyer and co-panelist Robyn Marino, Philadelphia-based general counsel for Cigna Corp., provided attendees a rundown of current court cases across the United States, where 29 states and the District of Columbia have passed medical marijuana legislation and eights states have recreational marijuana statutes.

Both admitted their presentation was already out-of-date, with a game-changing case out of Massachusetts’ highest court in July causing those who deal with employers and marijuana to rethink drug testing and discrimination.

The Massachusetts Supreme Judicial Court on July 17 ruled that Advantage Sales and Marketing L.L.C., which fired new employee Cristina Barbuto after her pre-employment drug screening showed positive for marijuana use, could be sued under federal handicap discrimination statutes. Ms. Barbuto suffered from Crohn’s disease and used medical marijuana to stimulate her appetite, according to court documents.

“This case shines a spotlight on what employers should be thinking about when they encounter an applicant with a medical marijuana card,” said Mr. Meyer, who advises clients to rethink drug testing if the job description is not one related to workplace safety.

“Put the law aside for a minute, let’s say you are not hiring for a safety sensitive job. Let’s say it’s an office job. Even if there is no duty to accommodate, maybe you just want to accommodate that person,” said Mr. Meyer. “If they come to work and they do their job, why not just hire them?”

Employers should also train their supervisors on identifying impairment — that drug tests do not paint a clear picture as marijuana stays in a person’s system for weeks, both said.

Ms. Marino urged employers to maintain documents on workers, in case issues arise later on. “Consistent, comprehensive employee documentation,” she said. “It’s training your frontline managers and seeking counsel.”

Meanwhile, a separate, interactive session on opioid use in the workplace provided attendees an overview on why opioids are so addictive and what employers can do to curb use in the workplace.

Opioids tend to affect a part of the brain that releases dopamine, which tends to increase satisfaction and happiness, but users tend to need higher doses to maintain the feeling over time, said Dr. Michael Coupland, West Palm Beach, Florida-based network medical director for IMCS Group Inc., a national network of clinicians utilizing an evidence-based biopsychosocial functional model of disability.

Eventually, the link between the “primal brain” and the thinking brain tends to wear down, he said.

“The thin pathway between the thinking brain and the primal brain, that disappears within about five days of opioids (use),” he said. “The brain gets hijacked… That’s why it’s hard to talk to someone who’s on opioids on why they shouldn’t do opioids.”

Focusing on fit-for-duty testing can better help employers maintain safe workplaces, especially when a prescription for opioids falls into the disability category — an issue now affecting marijuana use among workers, he said.

“Even if you do a drug screen and it pops up and they have a prescription, then you need a policy,” he said.

As part of his presentation, he provided attendees with sample fit-for-duty test, which gauged reaction time, attention span, memory and impulsiveness.