These people suffer from what's called generalized anxiety disorder (GAD), says Case Western Reserve psychologist Amy Przeworski.

Individuals with GAD frequently put social relationships with family, friends, or coworkers at the top of their lists of worries, but the negative methods they use to cope -- from over nurturing to extreme detachment -- may be destructive.

Przeworski and colleagues at Penn State University observed that people in therapy for GAD manifested their worries in different ways based on how they interact with other people.

In two studies the researchers found four distinct interactive styles prominent among people with GAD -- intrusive, cold, nonassertive and exploitable.

Both studies supported the presence of these four interpersonal styles and their significant role in how people with GAD manifested their worrying.

"All individuals with these styles worried to the same extent and extreme, but manifested those worries in different ways," Przeworski said.

Take the examples of two people with similar worries about someone's health and safety.

One person may exhibit that worry through frequent intrusive expressions of concern for the other person. Think of the parent or spouse who calls every five minutes to get an update on what's happening.

Another person may exhibit the worry by criticizing the behaviors that the person believes to be careless or reckless.

"The worry may be similar, but the impact of the worry on their interpersonal relationships would be extremely different. This suggests that interpersonal problems and worry may be intertwined," Przeworski says.

She suggests that therapies to treat GAD should target both the worry and the related interpersonal problems.

Most treatments for GAD rely on cognitive behavioral therapy, a treatment that is usually successful for about 60 percent of people, a percentage considered successful in therapy. However, one way to improve therapy for worriers may be to integrate techniques that target the interpersonal relationship problems.

The research was part of larger study supported by the National Institute of Mental Health.