With the ‘chemical imbalance’ theory in doubt, what’s next for depression care?

By Serena McNiff HealthDay Reporter

(Health Day)

TUESDAY, September 6, 2022 (HealthDay Now) — For Mary Christ, the idea that the Depression is a chemical imbalance in the brain has always seemed true to personal experience.

A former educator, Christ, 57, has taken antidepressants for much of her adult life. She experienced anxiety and panic attacks from an early age, and these feelings intensified in adulthood and eventually sent her into a state of deep depression.

When she started taking antidepressants in her thirties, Christ slowly regained her functioning and felt her true return. She said the medication helped her stay “on a level”.

Christ is not alone in his opinion: According to polls, more than 4 out of 5 people believe that depression stems from imbalanced brain chemicals and, in particular, low neurotransmitter levels serotonin. This explanation for depression has a corresponding treatment – antidepressants known as SSRIs which are designed to increase serotonin levels and correct the so-called imbalance.

Psychiatric experts, however, say this understanding of depression was debunked long ago. The theory was first offered in the 1960s and was heavily promoted in the 1990s when pharmaceutical companies began to develop and market this new class of antidepressants fitting this theory.

While SSRIs were moderately effective in clinical trials, the serotonin theory was never proven. And the latest research suggests that there isn’t just one cause of depression.

The dissonance between the public understanding of depression and the psychiatric literature came to a head recently when British psychiatrist Dr Joanna Moncrieff, co-author Mark Horowitz and colleagues published a thorough examination existing studies in July and put the final nail in the coffin on the serotonin theory. The review was presented as an eye-opener, which demystifies the common understanding of depression and its associated treatment.

“The vast majority of the general public thought it was an established fact, that there is evidence to support this idea that depression is caused by low serotonin, and indeed many people take antidepressants because of this belief,” said Moncrieff, professor. of critical and social psychiatry at University College London, said during a HealthDay Now Interview. “That’s why I thought it was really important to do this research and be able to say definitively about the state of the evidence for this theory.”

The study generated widespread media coverage and controversy, with Moncrieff and his co-authors pouring out broad criticism on the depression treatment landscape. Other psychiatrists have pointed out the difference between how well a drug works and how effective it is.

“We don’t really understand how statins work to lower cholesterol – we’re learning more about it. But the reason we use them is because of clinical trials,” said Dr. Srijan Sen, director of the center. depression at the University of Michigan.

SSRIs have been shown to provide moderate, often short-term, benefit to some people, especially those who have severe depression. “It’s not blockbuster drugs that help everyone,” Sen said. health day now. “But clearly there is a subset of people for whom these drugs work and a subset for whom they don’t.”

At the heart of the research, however, almost everyone agrees: Depression is a complex and variable condition, and there is no definitive explanation for why and how antidepressants can help.

For Mary Christ, all that matters is her personal experience with antidepressants, which she says helped bring her back to life. She may not understand the precise effects of the drug on her brain, but she thinks it triggers something positive.

“I can’t help but think and feel that this is definitely having a chemical impact on me,” Christ said during a health day now interview. “What exactly is going on with serotonin? I do not know. But clearly, if the research hasn’t strongly supported this, then there must be other things going on that they haven’t figured out. She said she hopes this new research will inspire a new surge of answers.

But patients should not expect simple explanations like the serotonin theory to be discovered in the future.

“I think it’s important to expect that there are some hiccups, some theories that unfold and some that don’t,” Sen said. “We shouldn’t let these studies and these jolts affect our understanding of whether the different treatments work.”

Encouragingly, the pipeline of new therapies has never been so crowded. In 2019, esketaminea drug derived from ketamine, became the first new depression drug to receive U.S. Food and Drug Administration approval in decades and is now an increasingly popular option for patients who have not benefited from antidepressants. . Although not yet approved, psychedelic therapy for depression is also the subject of huge research efforts and funding.

Still, Sen cautions against repeating old mistakes.

“I remember advertisements from pharmaceutical companies showing us changes in neurons and serotonin levels, and it’s overly simplistic and suggesting that we understand what’s going on,” he said. “I think we should be humble now that we don’t, but also clear that understanding is not what drives our treatment recommendations.”

SOURCES: Joanna Moncrieff, MD, professor, critical and social psychiatry, University College London; Srijan Sen, MD, PhD, professor, depression and neuroscience, and director, Frances and Kenneth Eisenberg and Family Depression Center, University of Michigan; Mary Christ, former educator; Molecular psychiatryJuly 20, 2022, online

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Sharon D. Cole