A number of states have legalized recreational and/or medical marijuana. Employers must adapt their policies in some manner, but the challenges goes deeper. Research has indicated a relationship between marijuana use and mental health issues.
— By Jeremiah Prince

Ten states have legalized recreational and medical marijuana as of May 2019, while 15 states chose to decriminalize marijuana and 33 states and Washington, D.C., legalized medical marijuana only. Any way the numbers are considered, most U.S. employers are challenged by changing cannabis laws that increase the likelihood of more marijuana use among employees.

In the new order of things, legalized cannabis can lead to employees making the false assumption their employer cannot maintain drug testing for cannabis. People using marijuana for medical purposes need accommodation like any person using legal prescribed drugs.

The final complication is the unknown definitive connection between mental health and cannabis use, adding to the complexity of mental health programs and creating a scenario in which more employees will struggle with mental health issues.

Cannabis Impairs
Cannabis, or marijuana, is a psychoactive drug, meaning it is mind-altering.

Legalizing marijuana means people can more easily obtain the drug. It also has already led to new products for sale that have marijuana as an ingredient. Marijuana is used as a recipe ingredient in foods like brownies and is infused into cooking oil and butter. It can also be consumed in a variety of ways – smoking, vaping, gravity bongs, oral ingestion, sprays, tinctures, and topical oils and creams.

Marijuana is still illegal at the federal level, but the illegality is quickly becoming a moot point.

A psychoactive drug is a chemical substance that acts on the central nervous system and alters brain functioning. Cannabis contains tetrahydrocannabinol (THC) which binds to the cannabinoid receptors in the brain, interfering with the communication between neurons. The results are changes in mood, behavior, and/or awareness. It can impair memory and body movement, cause hallucinations and delusions, make it difficult to problem solve, and alter a person's sense of time.

There are four categories of psychoactive drugs – depressants, stimulants, opioids and hallucinogens. Marijuana is a hallucinogen. Making marijuana legal is really no different than making alcohol, sleeping or pain pills, or other prescription drugs legal.

Protecting Workplace Safety
Employers are wondering how to handle the changes in the law. Unfortunately, making it easier to buy marijuana means it is likely more people will use the drug, and people in states where it is not legal can access it easier.

Employees who are high on marijuana pose a safety risk due to mental impairment, but they also may experience physical problems like breathing problems from smoking and a substance use disorder. Even beyond the psychoactive and physical effects, researchers have linked marijuana to mental health problems like anxiety and depression.

For employers, the changes concerning marijuana's legal status does not have to make much of a difference in policies and procedures for drug use and drug testing in the workplace. Like alcohol and prescription drugs, marijuana may be legal, but that does not mean employees should be allowed to use it unless there is a documented medical reason.

Some states, but not all, do have job protections. Employees in these states are often registered medicinal users and are included in state disability non-discrimination laws. An employer usually cannot fire someone who fails a drug test for marijuana in these cases. However, the employer also does not have to allow an employee to stay in a position in which marijuana use can increase safety risks or harm job performance.

When Reasonable Accommodation for Medical Marijuana is Reasonable
Practically speaking, employers can maintain the same policies for medical marijuana that apply to medical use of any psychoactive drug or alcohol which is legal. An employer never has to accommodate employee drug use in the workplace, but anti-discrimination laws, like the American Disabilities Act (ADA) and state laws, would also lead employers to make reasonable accommodation for legal drug users. New York law says there is a duty to accommodate a certified patient using medical marijuana.

An employer in a state with no reasonable accommodation law must be careful to make adverse employment decisions based on a person's marijuana use and not on a medical condition that protects the employee under the ADA.

The challenge is in determining reasonable accommodation. For example, someone using medical marijuana should not be in a position requiring driving a company vehicle. The employer needs to place the person in a position that does not pose a safety risk. In states that have legalized recreational marijuana, employers do not have to accommodate recreational users. Medical users can produce medical confirmation of need, but recreational users cannot.

Each employer should review the state's laws on cannabis and ensure there is a good understanding of what the law says and how it can be applied in the workplace. It is important for employees to have a clear understanding of drug policies on use and testing, and the potential consequences of various circumstances.

Making Mental Health Issues Worse
Unfortunately, current drug tests can detect THC metabolites, but they cannot determine impairment level. There is also no way to know if an employee used cannabis at work or on personal time. The other challenge is addressing the impact of marijuana use on mental health in the workplace.

According to the American Psychiatric Association, people who are diagnosed with marijuana use disorder have high rates of mental health disorders like anxiety, ADHD and depression. If someone has a mental health issue and begins using marijuana, the person's medical condition may worsen.

The relationship between cannabis and the full impact of the drug on people and their work performance is not documented because, until recently, marijuana has been illegal so people did not want to admit they used it.

One thing is for certain: Employers will need to address the challenges of cannabis legalization. It is a workplace safety and employee health issue. They need to be informed about the laws in the organization's states of operation, review and adapt current policies, and stay current on related issues of mental health. Employers are allowed to have and enforce a drug-free workplace, and federal law says marijuana is still illegal. Lax rules in response to a lax employee attitude about marijuana can lead to expensive court cases should someone get injured.

There are no definitive answers right now, but research will accelerate now that people can admit their marijuana use.