The rate of mental disorders among smokers is increasing, a new study concludes. More recent smokers have the highest risk, HealthDay reports.

The study analyzed data from 25,000 people. The researchers found that while the national smoking rate has been declining since the 1960s, the percentage of smokers who are nicotine-dependent has been increasing. The risk of substance use disorders rose among all smokers with each decade, regardless of whether they were nicotine-dependent.

Smokers who were nicotine-dependent and began smoking in the 1980s were more likely than older smokers to have disorders such as bipolar disorder, antisocial personality disorder or attention-deficit hyperactivity disorders, the researchers report in Molecular Psychiatry.

“Our study confirms that recent smokers, though a relatively smaller group than those who started smoking decades ago, are more vulnerable to psychiatric and substance use disorders,” lead author Ardesheer Talati of Columbia University Medical Center said in a university news release. “These findings suggest that today’s adolescent and young adult smokers may benefit from mental health screening so that any related psychiatric or substance use problems can be identified and addressed early.”

Study co-author Katherine Keyes noted the findings “suggest that cessation efforts that treat both withdrawal from nicotine and underlying mental health conditions are increasingly crucial.”