Adults who continue occasional “hard” drug use into middle age are at increased risk of premature death, a new study suggests. The study looked at the effect of using hard drugs, such as cocaine, opioids and amphetamines, according to Science Daily.

The study included 4,301 adults. While 85.8 percent had never used hard drugs, 7.9 percent were occasional users early in life, 3.7 percent were occasional users early and later in life, and 2.6 percent used hard drugs frequently and then became occasional users later in life. The study found those who continued occasional use into middle age were more likely to continue harmful risk behaviors such as smoking, and were more likely to die.

In the Journal of General Internal Medicine, the researchers reported that people who were heavy drug users in young adulthood, and continued using drugs at lower levels into their 50s, were five times more likely to die compared to those who did not, according to a news release from the University of Alabama.

“Fourteen percent of the people in the study reported recent hard-drug use at least once, and of these, half continued using well into middle age,” lead researcher Stefan Kertesz said in the news release. “But, most of the drug users in our study were not addicts. They were dabblers who used just a few days a month.”

Kertesz noted that it cannot be assumed these people died of drug overdoses. He said that middle-aged users of hard drugs are at higher risk of bad outcomes, which could include death from trauma, heart disease or other causes that are not directly related to their drug use, compared with adults who had stopped using drugs.

He said people who use hard drugs into middle age tend to have grown up under economic and psychosocial stress, and continue to smoke and drink.

“Based on the data we hope to offer better advice to primary-care doctors struggling with the rising tide of drug-taking by adults who have not left behind many of the bad habits they learned in young adulthood,” he said.