Could the effect of antidepressant drugs simply be the patient’s misinterpretation of side-effects? A new Swedish study runs counter to such claims. (Photo: Intarapong/Shutterstock/NTB scanpix)

Scientists rebut claim that antidepressants don't work

A theory that antidepressants don’t really work has caught a lot of attention in international media. A new Swedish study punches holes in such arguments.

Researchers at Sahlgrenska Academy in Gothenburg have published a research article in the journal Molecular Psychiatry which picks apart the claims that the apparent help from antidepressant drugs is just a placebo effect.

“The hypothesis is bizarre. I’m surprised that such claims ever attracted so much attention,” says Elias Eriksson, professor of pharmacology at Sahlgrenska.

Confusing side-effects with effects

The criticism of antidepressant drugs has been led by, among others, the American psychology researchers Irving Kirsch and Guy Sapirstein in the book “The Emperor’s New Drugs: Exploding the Anti-depressant Myth”.

Critics of the use of selective serotonin reuptake inhibitors (SSRI) say these antidepressant drugs have seemed effective because users can commonly experience side-effects. A patient suffering depression can feel these effects and this enhances their expectations of relief – and this assumption or hope itself alters their mood and hampers depression.

The critics have reassessed depressed patients who participate in studies where some are given real medications and a control group is given a placebo, for example a “sugar pill”. They think the latter have been able to guess they are in the group getting real medicine. They understand that the medication they took was real because they suffer side-effects such as nausea or reduced libido.

Test persons who experience one or more side-effects conclude they have indeed been medicated and the resulting placebo effect alleviates their depressions.

Critics of the drugs think researchers and pharmaceutical companies have misunderstood this phenomenon when claiming SSRIs are effective.

Seen in earlier tests

To test whether the effect of SSRIs is really just a placebo, researchers at Sahlgrenska Academy in Gothenburg have re-analysed the data from numerous studies showing that the SSRI medications such as paroxetine and citalopram really work.

“We are the first ones to really put this [placebo hypothesis] to the test. We can definitely conclude that the hypothesis is wrong,” says Elias Eriksson.

Clearly works against depression

A Sahlgrenska Academy press release states that the Swedish researchers analysed 2,273 patients who were given SSRI and 1,071 that were given a placebo.

They claim their analysis showed clearly that the SSRI pills worked better than the placebo pills.

This is also the case with the 20 percent of the SSRI patients who did not suffer any side-effects. That really unhinges the side-effect hypothesis.

“It’s unfortunate that the media has often described these as ineffective. This can lead certain patients to balk at making use of an effective and perhaps lifesaving treatment,” warns Elias Eriksson.

More debate on SSRIs

Antidepressants have a knack for stirring up debate. This spring ScienceNordic’s partner forskning.no covered a battle between Danish and Norwegian medical professionals.

Researchers at the University of Copenhagen warned that depressed patients who take SSRIs can actually become sicker than those who received placebos.

“We conclude that these pills are not benefitting patients,” said Janus Christian Jakobsen, a University of Copenhagen scientist, to forskning.no in March 2017.

The Danish researchers had conducted a meta-study of the results of 131 studies of SSRIs.

But Jakobsen and his colleagues in Copenhagen were strongly criticised by other experts in the field, including Ulrik Fredrik Malt, professor emeritus of psychiatry at the University of Oslo.

Malt thought the Danes had been rather bombastic in their assessment. He strongly suggested to forskning.no that the Danish researchers’ personal attitudes about antidepressants were shining through in their research results.

Janus Christian Jakobsen in Copenhagen countered that the criticism against his research actually emanated from factors such as prestige and money, not to mention the financial interests of the pharmaceutical companies that produce antidepressants.

References:

I. Kirsch: “The Emperor’s New Drugs: Exploding the Antidepressant Myth”, Basic Books, 2011

F. Hieronymus et al.: “Efficacy of selective serotonin reuptake inhibitors in the absence of side effects: a mega-analysis of citalopram and paroxetine in adult depression”, Molecular Psychiatry, July 2017.

Translated by: Glenn Ostling

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