Participants will be offered free help in the form of proven, beneficial treatments by psychologists.

The trial, conducted by the Australian Centre For Addiction Research at the University of Sydney, will be held in Parramatta and surrounds, and at locations in Randwick, Camperdown and North Sydney.

What sets this study apart from others is the approach researchers are combining treatments rather than separating the two problems.

"Generally, post traumatic stress disorder and excessive alcohol use are treated separately,'' Alicia Visser, a clinical psychologist at the university, said.

"At present there are few treatment options available that address these problems together.

"We're trying to see whether a more integrated program would be more effective, whether there are better outcomes for clients when treatment for alcohol and post traumatic stress disorder is combined.''

Currently, 30 people are taking part in the trial but a further 140 people are needed.

Potential participants need to be experiencing a trauma that is continuing to cause them distress and need to be drinking at "risky levels''.

"This means greater than 28 standard drinks a week for men and more than 14 standard drinks a week for women.''

Miss Visser said the study was a "valuable service to the community''.

"People with these problems do not always seek help, often due to lack of knowledge as to what is available to them,'' Ms Visser said.

"We encourage them to give us a call to see if they are right for the study.''

Details: Alicia Visser, 0432 396 768.