Older Australians overprescribed antidepressants

Older Australians are being overprescribed medications for depression, according to a study by University of Queensland researchers published in the Australian and New Zealand Journal of Psychiatry.

Dr Samantha Hollingworth, Senior Research Fellow at the School of of Population Health, said the study found very high prescribing rates in older Australians, especially those over 85 years old despite national mental health data indicating that depression and anxiety was a decreasing problem in this age group.

"While the under 50s have a higher prevalence of depression and anxiety, it is the over 85s who are receiving the most medication," Dr Hollingworth said.

The study found that the prevalence and treatment of depressive and anxiety disorders are highest in those aged under 50, after which it declines rapidly. There are peaks in prescribing of antidepressants in those aged in their late 50s and early 90s, with the highest use in those aged 90–94 years.

Co-author, Professor Harvey Whiteford, Kratzmann Professor of Psychiatry and Population Health with the Queensland Centre for Mental Health Research, said it appeared older Australians were receiving antidepressant medications for reasons other than the treatment of conditions for which these drugs have marketing approval, or for depressive and anxiety symptoms that do not reach the threshold for a diagnosis.

"If these medications are being prescribed for emotional distress or insomnia, or mild symptoms that don’t constitute a diagnosis of affective (depression) or anxiety disorder, they could be treated using psychological rather than pharmacological means," he said.

Professor Whiteford said another issue was the high cost of antidepressant drug use.

"These medications are often very expensive and there are flow on cost burdens. For example, a current popular drug is venlafaxine, which was recently included in the list of the top 10 drugs used, based on cost," he said.

The unique study compared treatment rates reflected in drug dispensing data from throughout Australia, with details on the prevalence of depression and anxiety from the National Survey of Mental Health and Wellbeing 2007.

(Source: University of Queensland: Australian and New Zealand Journal of Psychiatry: May 2010)