BUFFALO, N.Y. -- To curb employees' on-the-job substance use and intoxication, bosses need to do more than just be around their employees all day, according to a new study from the University at Buffalo Research Institute on Addictions (RIA).

"It's only when employees think their supervisor knows how to detect substance use -- and is willing to do something about it -- that employees' drinking and drug use on the job decreases," explains Michael Frone, PhD, senior research scientist at RIA and research associate professor of psychology.

"Contact with a supervisor, no matter how often, is not a strong enough deterrent for some employees, our research finds."

Frone's study included 2,429 participants, ranging in age from 18-65, employed in the civilian labor force and from households located in the 48 contiguous states. They were interviewed in a random telephone survey for 45 minutes.

The study is part of a $1.4 million research project, "Workplace Substance Use: A National Prevalence Study," funded by the National Institute on Alcohol Abuse and Alcoholism (NIAAA). The results are published in the current issue of the Journal of Studies on Alcohol and Drugs.

Frone found that workers reported drinking less on the job when they thought their supervisors could detect substance-use problems and were willing to take corrective action. But, supervisor enforcement had no relation to employees' off-the-job alcohol use and intoxication.

When it came to illicit drugs, however, supervisor enforcement produced lower levels of drug use both on and off the job, the research shows.

"The finding for off-the-job illicit drug use is not surprising because company policies often sanction such behavior. Even so, supervisor enforcement had a stronger relationship to on-the-job compared with off-the-job illicit drug use," Frone says.

The results, he says, have several practical implications. For researchers, the findings indicate that factors influencing employee substance use are more complex than previously thought.

For employers, the study suggests that supervisor training in how to spot and confront employee substance use would help reduce alcohol and illicit drug use on the job, thereby improving employee productivity.

"To the extent that supervisor social control reduces substance use at work, our other research suggests that it may also reduce stress and improve morale among the majority of employees who do not engage in such behavior," Frone adds.

According to Frone, previous research did not make a consistent connection between supervisor social control and employee substance use because it failed to consider simultaneously the dimensionality of supervisor social control, the context of substance use and substance legality.

A social and organizational psychologist, Frone is the first researcher to conduct a broad national study of both workplace and workforce substance use, as opposed to just workforce substance use. This study, conducted during 2002-03, assessed the prevalence, predictors and outcomes of workplace and workforce substance use.

Frone's next national survey will take a broader look at workplace stress, including the recent recession, and both workforce and workplace alcohol use and impairment. The $2.2 million study "Work Stress and Alcohol Use: A National Study of Unresolved and Unexplored Issues," was funded by the National Institute on Alcohol Abuse and Alcoholism (NIAAA).

"We hope to identify combinations of work stressors and identify subgroups of vulnerable workers that are associated with stress-induced drinking, and spot variables that may help explain why work stress is related to employee alcohol use," Frone says.