Employers, get ready.

Walking through your doors in our brave new world of legalized marijuana will likely be any number of employees stoned. If you ask yourselves just how pot – more pervasive and public – will impact the workplace, the short answer is: in ways you won’t like to imagine, none of them pleasant.

My vantage point is unique, blending both the personal and professional. I’m an addict in recovery (for 32 years) who owes a personal, painful path of drug dependency over the decades to smoking my first joint before age 16. It was the beginning of my five-year addiction to marijuana that was all downhill from there: heroin, cocaine, prescription drugs.

In my professional role today on the front line as an addiction therapist for 25 years, I have treated thousands of addicts, of whom I estimate 95 percent fell off that same cliff that started with recreational marijuana.

I do not have to sift through stacks of studies, because I know from personal experience and evaluating other addicts about the psychological downsides to using marijuana – the panic and anxiety attacks, uncontrollable anger, lack of motivation and impulse control, and stunted brain growth at younger ages.

Stoned or drunk?

Apply such unfortunate characteristics to employees at virtually any business. In essence, is there any difference in coming to work stoned or drunk? The effect on your business is the same – the missing productivity quotient, employees lacking focus, motivation, sleep. There’s the additional soft cost of monitoring, disciplining, and even terminating, errant employees. And, if your business relates to safety products or services, what type of testing procedures are you implementing?

A frightening argument is that smoking a joint is as acceptable as having a beer at lunch. Not by a long shot. There is a key distinction about using marijuana. Although moderate alcohol consumption can be a socialization tool, the same cannot be said for pot. Getting stoned is the sole reason for using.

There’s no moderation with marijuana. This is truer now than ever before because today’s marijuana is significantly more potent than what most people realize. While I don’t expect everyone will become addicted to pot, my concern is that it’s within the realm of probability that 10 percent to 20 percent of those trying it for the first time will become hooked and move to harder, more dangerous drugs. The notion that marijuana helps ease PTSD, anxiety, and other health disorders is irresponsible. So does a drink of Scotch, but does that really treat the underlying disorder?

The irony is that greater access could have a positive effect on my addiction treatment business. I don’t view that as positive. I accept the new law, but ask people to remember that trading on the message that the drug is harmless is a fool’s mission. It’s not harmless – just ask a few thousand of the permanently damaged addicts I have treated.

Understand from the get-go that any number of employees will simply want to get loaded, coast through the workday, and check out. How does one calculate this cost to business?

Howard C. Samuels is chief executive of the Hills Treatment Center in Los Angeles and author of “Alive Again.”