The latest study published in the Australian and New Zealand Journal of Psychiary reveals older Australians as the country's primary consumers of antidepressant drugs, despite higher rates of depression observed among younger population.

The study by the University of Queensland showed prescription of antidepressant drug is highest for patients aged 85 and above, suggesting the drugs are prescibed for reasons other than for the treatment of diagnosed depressive disorders.

The analysis had looked into the Pharmaceutical Benefits Scheme prescription data for antidepressants from 2002 to 2007 that also included medications used for Australia's aged-care services.

Harvey Whiteford, Professor of Psychiatry and Population Health with the Queensland Centre for Mental Health Research said concerns have been raised due to the overprescription of antidepressants for older people.

He says, These people may have multiple physical problems, they may have lost a spouse, may be in a nursing home, but to me, most of that is not depression.

Prof Whiteford said they should not be medicated and treated with drugs - the potent drugs should not be used as a treatment for emotional distress or insomnia, or other mild symptoms that are not supported as a criteria of a depressive or anxiety condition.

The problems faced by older Australians should be approached using psychological methods rather than pharmacologically, said Prof Whiteford.

The results from the national survey on mental health and anxiety disorders for 2007 were compared with the patterns of prescription nd it showed depression rates were significantly higher among Australians under 50 and with increasing age, the condition declines.

Dr Samantha Hollingworth, senior research fellow at the university's School of Population Health said while Australians under 50 have higher prevalence of depression and anxiety, the group receiving most antidepressant medication falls in the group of people over 85.