Antidepressant use on the rise

Prescriptions 2008-2015

The number of Kiwis being given antidepressants is continuing to increase, yet researchers admit there is no evidence to suggest they are improving mental health or reducing suicides.

An Otago University study published in the New Zealand Medical Journal on Friday examined prescribing trends for antidepressants between 2008 and 2015.

It found the highest antidepressant user group was European women, particularly those aged 65 and over, which surprised Professor Roger Mulder, one of the lead researchers.

‘‘I guess it’s because they present with distress more often, but if you look at the epidemiology of depression, they’re probably not the most likely group to get severe, melancholic depression, which is when you say antidepressants should be used,’’ Mulder said.

‘‘What we seem to be doing is prescribing more and more, especially for white females, and we don’t have evidence that that’s resulted in a significant reduction in levels of community distress. If anything, levels of community distress seem to be increasing and it obviously hasn’t resulted in a decrease in the rates of suicide.’’

While prescription numbers increased during the research period, the rate of those increases was slowing, in keeping with prescription patterns in other likeminded countries.

‘‘The fact that our community measures of mental health aren’t getting better is not unusual either. Australia and the United Kingdom, the USA and Canada – there’s very similar trends,’’ Mulder said.

‘‘It would suggest that giving people more and more antidepressants may not be the best way to manage what on earth is going on, which no-one quite understands because as a community we seem to be getting more and more distressed.’’

Researchers have attributed the rise to a variety of factors, including improved recognition of depression, changes in patientdoctor attitudes and a broadening range of conditions treated with antidepressants.

Mulder, who was based at Otago University’s Christchurch campus, said the research raised questions about the way prescriptions were being used.

With no evidence to suggest more antidepressant prescriptions improved community mental health or reduced suicide, the researchers suggested a change in tack: ‘‘Perhaps it is time to switch emphasis from a ‘treatment gap’ to a ‘quality gap’ so that antidepressant use is targeted more optimally at those who are most likely to benefit.’’

The findings show selective serotonin reuptake inhibitors, which work by increasing the levels of serotonin in the brain, accounted for about half of all antidepressant prescriptions.

12.6 per cent of all New Zealanders were prescribed an antidepressant in 2015.

The most prescribed group was European women aged 65 and over (22.8 per cent). Prescriptions increased across all ethnic groups. Largest class of drugs prescribed were SSRIs

(57 per cent of all antidepressant prescriptions). Females had higher antidepressant use than males in all age groups. Source: NZ Medical Journal