First-degree relatives of alcoholics are more likely to also become addicted to alcohol, as well as to other drugs such as cocaine, according to new research.

Moreover, a close family history of alcoholism appears to put people at increased risk of mental health problems, such as depression and panic disorder.

These results demonstrate that “other disorders go along with alcohol dependence in families,” lead author Dr. John I. Nurnberger, Jr. of the Indiana University School of Medicine in Indianapolis told AMN Health.

To protect themselves, children of alcoholics should try to “put off” drinking alcohol, Nurnberger said, since starting to drink as a teenager appears to increase the risk of becoming an alcoholic. Children with a close family history of alcoholism should also avoid trying different drugs, since they are more at risk for having problems, he added.

“They should know that ‘sampling’ of substances might cause more problems for them than it would for other young persons,” Nurnberger said.

Previous research has shown that alcoholism tends to run in families, and genetics are partly to blame. For instance, sons of alcoholics who were adopted by other families had a similar rate of alcohol abuse as sons of alcoholics who were not adopted.

To investigate whether other disorders might also be more common when there is a family history of alcoholism, Nurnberger and his colleagues interviewed 8296 people with a first-degree relative who is an alcoholic, and 1654 people without that family history.

The rate of alcoholism among people with a family history ranged from 29 to 37 percent, depending on the definition used. The investigators diagnosed the problem in between 14 and 21 percent of the study participants who did not have an alcoholic relative.

Overall, relatives of alcoholics were twice as likely to become addicted to alcohol as people without a family history of the disease, the researchers report in the Archives of General Psychiatry.

Relatives of alcoholics were also significantly more likely to become addicted to other drugs, including sedatives, stimulants, opiates and tobacco. For instance, people with a close family history of alcoholism were more than three times more likely to become addicted to cocaine.

Moreover, relatives of alcoholics had a higher risk of depression, panic disorder, post-traumatic stress disorder, and antisocial personality disorder, which can dispose them to violence.

To Nurnberger, these findings suggest that there may be “shared genetic vulnerability factors” that put people at risk of multiple disorders if they have a family history of alcoholism.

The next step, he said, is to look for those “shared causes” that may link these disorders.

SOURCE: Archives of General Psychiatry, December 2004.