1 Selective serotonin reuptake inhibitors (SSRI) – sales, withdrawal ...

M. Nielsen and P. Gøtzsche / An analysis of psychotropic drug sales 131
the treatment is not evidence-based. For example, escitalopram is almost 20 times more expensive than
citalopram, even though the chemically active ingredient is the same.
The change in treatment of anxiety disorder, from benzodiazepines to newer antidepressants, has
happened despite a lack of evidence in support of this change, and marketing strategies could therefore
have played an important role [14]. This change in prescription habits might have opened the market for
new antidepressants.
Guidelines have urged drug treatment of depression and anxiety [15, 16] and have emphasized the
risks of under-treatment. They are often influenced by the companies’ marketing strategies and those
who write them usually have numerous conflicts of interest in relation to receiving industry money [17].
More than 60% of the doctors participating in the working group on the Danish depression guideline had
financial ties to the pharmaceutical industry [15, 18].
The prevalence of psychiatric disease and distress should also be interpreted in the light of changes in
diagnostic and classification systems and a new symptom-based approach to substantiate the diagnosis
as described in the Diagnostic, Statistical Manual of Mental Diseases III [19]. New disorders have been
included and existing disorders ’exploded’, e.g. anxiety neurosis was split into seven new disorders [19].
The symptom-based approach has been criticized for creating diseases, classifying normal life distress
and sadness as mental disease that should be treated with drugs [19]. The symptoms described as criteria
for depression are now broad, for example fatigue, insomnia or diminished ability to concentrate, and do
not distinguish between a disorder and expected reactions to a situational context, for example the loss of
a beloved person with symptoms persisting for more than two months [19]. Further other life crises like
divorce, serious disease or loss of job are not mentioned as exclusion criteria [19]. Thus, it is likely that
changes in the diagnostic classification systems have contributed to the increased sales of SSRIs, and that
part of this increase represents over-diagnosis and over-treatment. This is further supported by the fact
that 56% of the DSM IV overall panel members had financial ties to the pharmaceutical industry, and in
the panel on “mood disorders”, 100% had such ties [20]. This indicates serious problems with conflicts
of interests, not least because the ties were especially strong in those diagnostic areas where drugs are
first line of treatment.
5.1. Strengths and weaknesses
We combined statistics from different time periods, based on varying ATC levels, which gave us the
possibility to present data for usage at an overall level. The three different data sources all used ATC and
DDD, and there are some overlaps between the data sources, which confirmed the reliability of the data.
Data from the secondary sector are not included in the analysis, as prescription is low and therefore not
important for the overall picture. Our data are on sales, which cannot be equated with usage. Another
limitation is that the data were available as DDD, but the defined daily dose might be lower or higher
than the average dose of a drug in practice. For example the DDD for citalopram is 20 mg [9] but the
recommended dose varies between 10 mg and 60 mg [3].
6. Conclusion
The sales of psychotropic drugs has fluctuated widely over a 37-year period. We believe that the decline
in sales of benzodiazepines was primarily due to the recognition that they cause serious dependency and
by initiatives at a national level to curb their use, and that the recent steep increase in sales of SSRIs is a
direct consequence of marketing pressures, as the effect of the SSRIs is overestimated [7, 8].