(Rick Bowmer/AP)

Roger Roffman is a professor emeritus of social work at the University of Washington and the author of “Marijuana Nation: One Man’s Chronicle of America Getting High — From Vietnam to Legalization.”

On a warm Seattle summer evening in 1978, my wife wanted to talk about my increasingly frequent pot smoking: “I feel you’ve abandoned me, that the person I married — even when you’re sitting next to me on the couch — is not there.”

She had complained before about my use, and I’d tried to reassure her. “It’s not as if I’m stoned every day,” I’d counter. “Is it that different from having a drink or two?” I’d promise to cut back, but my resolve would give way, and I’d start to cut corners, making exceptions to the rules I’d set. Eventually I’d slide right back to where I started.

But this time Cheryl broke through: “Your mind goes to a different place, and talking with you when you’re stoned is really frustrating. I can’t help but think that, if you really cared about me, you’d want to be with me. You, not the stoned you. I feel rejected by you, and it hurts.” She began to cry, and I felt terrible.

Cheryl and I had at one time enjoyed getting stoned together occasionally, and then we changed. For her it became less desirable; for me it became more so. I tried to ignore the warning signs, among them the negative impact smoking marijuana was having on my teaching and writing. At 38, there was no avoiding the fact that I was addicted. I needed to quit.

Hoist by my own petard, it would seem. In the mid-1970s, I’d been the volunteer coordinator for the Washington chapter of the National Organization for the Reform of Marijuana Laws, lobbying across the state for the removal of criminal penalties for small-scale possession by adults.

Now, my struggle stimulated a new research interest in my work. Several years after quitting, I received my first federal grant to study counseling for marijuana addiction. My colleagues and I found that our typical subject — an adult who voluntarily sought support — had first smoked pot at age 15, first used daily at 19, typically was high for six hours a day, had been using daily or near daily for 10 years and had tried seriously to quit six times.

Today, about 2.7 million Americans over age 12 are dependent on marijuana, according to the National Survey on Drug Use and Health. For those who’ve used the drug at least once, the risk of becoming addicted is roughly 9 percent. It’s 17 percent for those who begin in adolescence, and for those who get high daily, the addiction risk is 25 percent to 50 percent.

Still, despite marijuana’s addictive potential, legalizing makes far more sense than prohibition. For that reason I was one of the sponsors of Washington state’s Initiative 502, which was approved by 56 percent of the voters in 2012. In addition to mandating a tightly regulated market, this new law earmarks excise taxes to support public education about marijuana, proven prevention programs targeting teens, treatment services for youth who get in over their heads with pot, research on marijuana and a systematic evaluation of the law’s impact on public health and safety.

Under prohibition, illicit marijuana enterprises have flourished, leading to horrific violence among competitors and other steep fiscal and social costs, including egregious racial inequities in how enforcement has been carried out. We are paying another price by maintaining a criminal approach as well, and that is the large-scale distortion of the truth about pot. Those arguing against legalization often exaggerate marijuana’s risks, rarely acknowledging that most occasional users are not harmed, while proponents of legalization tend to give short shrift to the risks to health and safety.

Legalization needs to be accompanied by a substantial investment in marijuana education, prevention, treatment, research and policy evaluation. The Washington model deserves a close look by others heading down the same path.

Several weeks ago, during a reading of my memoir in a Maine bookstore, I noticed a woman, likely in her mid-30s, sitting by herself. She moved all of us by talking about the struggle she had been undergoing trying to quit pot over the past nine months. Seventeen years of regularly getting high had brought her to a crossroads. “I didn’t want to leave myself behind,” she told us.

Clear away the hyperbole, and the rationale for legalizing marijuana is compelling. But stories like hers — and mine — about marijuana’s addiction potential absolutely have to be part of the discussion.