According to Canadian researchers seniors who are prescribed antidepressants such as Prozac, Paxil and Zoloft are almost five times more likely to commit suicide during the first month on the drugs than those given other medication to treat depression.
The new study adds to the controversy already surrounding popular selective serotonin re-uptake inhibitors, or 'SSRI' drugs.
Dr. David Juurlink, lead author of the study by the Institute for Clinical Evaluative Sciences (ICES), says doctors are far too liberal with such drugs.
The authors linked population-based coroner’s records with patient prescription records, doctors billing claims, and hospital data for more than 1.2 million Ontario residents 66 years of age and older from 1992 to 2000.
During the first month of therapy, SSRI antidepressants were associated with a five times higher risk of completed suicide than other antidepressants.
That risk was independent of a recent diagnosis of depression or the receipt of psychiatric care, and suicides of a violent nature were distinctly more common during SSRI therapy.
The study found three-quarters of the victims, over 66 years of age were men and most of those who took their own lives had not been prescribed antidepressants.
Juurlink says doctors should closely monitor seniors in the first month after they prescribe the medication, when the suicide risk is higher.
Prior studies have found an increased prevalence of suicidal thoughts among children and teens taking the medication, but little research on the possible link to self-harm in elderly patients has been done.
The researchers do say that drugs such as Prozac, Zoloft and Effexor are nevertheless essential for the most seriously depressed seniors and emphasise that the suicidal side effects are rare.
They believe an over-prescribing of SSRIs to older people who do not really need them may be exposing some to an unnecessary risk of self-harm.
As the suicide risk appeared to level out among the different types of antidepressants after the initial month of treatment, the researchers suggest that the heightened suicide risk may have resulted from an adverse drug effect.
Other experts say they are more concerned by the revelation that the majority of those who took their own lives had no drug treatment at all and demonstrates a massive under-treatment of the elderly.