Selective serotonin reuptake inhibitors (SSRIs) are among the most widely prescribed antidepressants in the world.

Drugs such as Prozac, Zoloft and Lexapro are used to treat depression and anxiety disorders in millions of people.

But some experts believe we have become over reliant on such drugs and that that has led some doctors to treat ordinary human distress as a medical illness.

“We have medicalized all emotional distress,” said Allen Frances, professor emeritus of psychiatry at Duke University School of Medicine in the US. 

“Eighty percent of antidepressants in the US are carelessly prescribed by rushed primary doctors as an easy way to get patients out of the office in 15 minutes,” Frances told DW.

“There is not a pill for every psychological and social problem,” he said.

What do selective serotonin reuptake inhibitors (SSRIs) do?

As their name suggests, SSRIs inhibit, or block, the reuptake (also known as “absorption”) of serotonin. Inhibiting the reuptake of serotonin increases its levels in the body. When serotonin levels are low, it can disrupt a person’s emotional well-being.

Serotonin is a neurotransmitter, a chemical messenger that carries signals between nerve cells throughout the body.

It is one of four so-called happiness hormones, and the one most associated with stabilizing mood. It regulates anxiety and sleep cycles, and creates an overall sense of well-being.

“We know that in depression, if you use SSRIs, you increase the amount of serotonin that cells can use to communicate. And this is the first step,” said Carmine Pariante, a professor of Biological Psychiatry at King’s College London, UK.

“Serotonin is a chemical that brain cells use to talk to each other. It is particularly important for emotions,” Pariante said.

So, maintaining a healthy level of serotonin is considered essential for fending off, or managing depression.  

“The person starts appraising the world around them,” said Pariante, “so, they become less negative about it.”

But some experts say depression involves more factors than just the one chemical imbalance — low serotonin levels — in the brain.

Are antidepressants overprescribed?

Joanna Moncrieff has long argued that SSRIs are overprescribed. “Psychiatry allowed people to believe that depression was caused by a serotonin deficiency and that antidepressants reversed this, even though this had not been proven,” said Moncrieff, a professor of Critical and Social Psychiatry at University College London, UK.

“There was never strong evidence — some findings here and there but never a consistent picture,” Moncrieff told DW, adding that their apparent effectiveness may instead result from a placebo effect. That’s when the simple act of taking a medication leads the person to believe it is helping, when in reality, it’s having zero effect. 

Most psychiatrists and organizations such as the American Psychiatric Association reject the idea that SSRIs are mainly effective as a placebo. Pariante is among them.

“There’s overwhelming evidence showing that antidepressants are effective in reducing depressed symptoms and, in particular, reducing the key symptoms of depression,” said Pariante, while also conceding that serotonin is just one factor in depression.

When to take SSRIs

Pariante said that SSRIs should only be prescribed for people who have clinical depression, a “constellation of symptoms” that goes beyond ordinary sadness.

“There has to be an impact on life that is beyond just feeling sad for a few days or a couple of weeks because of something that has happened,” said Pariante.

“Their life needs to be suffering or deteriorating because of the depression,” Pariante said. “For example, they cannot go back to work, or relationships within the family start falling apart because of the depression.”

Do SSRIs always help? No.

SSRIs do not always work, or work immediately, or all of the time. It depends on the patient — and it’s really important to get the best medical help you can.

In about one-third of cases, the first SSRI a person tries will not help them. Trying a second type of SSRI may help, but in 70-80% of cases they are ineffective.

“There’s no way at the moment to predict who will respond or who will not respond to antidepressants, or to SSRIs in particular, or to any specific SSRIs.

“They don’t work in everybody. There is a spectrum of response. It is trial and error, but it’s still the best option we have at the moment until we find something that allows us to personalize intervention,” said Pariante.

Consensus on antidepressants: ‘minimize SSRI-use’

Moncrieff said that the risks and side effects of SSRIs are often underestimated.

“They are a drug that interferes with our brain chemistry and other biological systems,” said Moncrieff.

Moncrieff said side-effects can include sexual dysfunction, dependence, osteoporosis, weight gain, bleeding and pregnancy complications. “We really should be minimizing their use as much as possible,” she said.

SSRIs may also dampen emotional responses broadly — causing a general, emotional numbing, which some people find helpful. But “many don’t like it,” said Moncrieff.

Pariante agrees that SSRI-use should be limited: When they do work, they should not be used indefinitely.

“In an ideal scenario, for the first episode of depression, you start on the antidepressant — maybe you start feeling better after six to eight weeks,” Pariante said.

“Then, six months, nine months, one year later maximum, the antidepressant should be slowly withdrawn and then stopped. Someone doesn’t need to be on antidepressants lifelong just because they had one episode of depression.”

Edited by: Zulfikar Abbany