Use of antidepressant drugs in the United States doubled between
1996 and 2005, probably because of a mix of factors, researchers
reported.
About six percent of people were prescribed an antidepressant in
1996 - 13 million people.
This rose to more than 10% or 27 million people by 2005, the
researchers found.
"Significant increases in antidepressant use were evident across
all socio-demographic groups examined, except African Americans,"
Dr Mark Olfson of Columbia University in New York and Steven Marcus
of the University of Pennsylvania in Philadelphia wrote in the
Archives of General Psychiatry.
"Not only are more US residents being treated with
antidepressants, but also those who are being treated are receiving
more antidepressant prescriptions," they added.
More than 164 million prescriptions were written in 2008 for
antidepressants, totalling $US9.6 billion in US sales, according to
IMS Health.
Drugs that affect the brain chemical serotonin like
GlaxoSmithKline's Paxil, known generically as paroxetine, and Eli
Lilly and Co's Prozac, known generically as fluoxetine, are the
most commonly prescribed class of antidepressant.
But the study found the effect in all classes of the
drugs.
Olfson and Marcus looked at the Medical Expenditure Panel Surveys
done by the US Agency for Healthcare Research and Quality,
involving more than 50,000 people in 1996 and 2005.
"During this period, individuals treated with antidepressants
became more likely to also receive treatment with antipsychotic
medications and less likely to undergo psychotherapy," they
wrote.
Social acceptance
The survey did not look at why, but the researchers made some
educated guesses.
It may be more socially acceptable to be diagnosed with and treated for depression, they said.
The availability of new drugs may also have been a factor.
"Although there was little change in total promotional spending for
antidepressants between 1999 ($US0.98 billion) and 2005 ($US1.02
billion), there was a marked increase in the percentage of this
spending that was devoted to direct-to consumer advertising, from
3.3% ($US32 million) to 12% ($US122.00 million)," they added.
Dr Eric Caine of the University of Rochester in New York said he
was concerned by the findings.
"Antidepressants are only moderately effective on population
level," he said in a telephone interview.
Caine, who was not involved in the research, noted that several
studies show therapy is as effective as, if not more effective
than, drug use alone.
"There are no data to say that the population is healthier. Indeed,
the suicide rate in the middle years of life has been climbing," he
said.
Olfson and Marcus said out-of-pocket costs for psychotherapy and
lower insurance coverage for such visits may have driven patients
away from seeing therapists in favour of an easy-to-prescribe
pill.
The rise in antidepressant prescriptions also is seen despite a
series of public health warnings on use of antidepressant drugs
beginning in 2003 after clinical trials showed they increased the
risk of suicidal thoughts and behaviours in children and
teens.
In February 2005, the US Food and Drug Administration added its
strongest warning, a so-called black box, on the use of all
antidepressants in children and teens.
