New Research on the Serotonin Theory of Depression – My Takeaways

The serotonin theory of depression has been extremely pervasive in how we discuss mental health, though no comprehensive review has ever fully broken down the relevant evidence.

At first glance, the selective serotonin reuptake inhibitor (SSRI) method of keeping serotonin in our synapses longer is pretty revolutionary.

But that’s assuming that an issue with serotonin at the brain level is what is causing depression.

Unfortunately, current research is showing that depression and mood issues are not simply related to serotonin alone. There are MANY other factors at play, chronic inflammation being a key role, along with other epigenetic drivers.

While over 77 million Americans are prescribed psychotropic drugs in the US (which is a number greater than any other developed country), with 45 million on antidepressants, we still have climbing rates of depression and anxiety, and prescriptions are being written for children as young as two.

A new systematic review and meta-analysis, published this week in Molecular Psychiatry, suggests that depression isn’t a chemical imbalance of serotonin or really anything to do with low serotonin at all.

Now, I have been preaching this for years, because the research has never supported the hypothesis, BUT the fact that it is in mainstream news outlets, after such a comprehensive study, is a really big deal. I attached it here. If research studies overwhelm you, scroll to the discussion at the end and it is very interesting.

My takeaways from the research:

There is no study showing that lowering serotonin induces depression.
Depression is about a lot more than low serotonin, so addressing serotonin only at the brain level may cause unintended long-term side effects.
Long-term use of antidepressants may cause deficiency of serotonin, along with poor activity of serotonin receptors (which is why dose always needs to be increased over time, I was there for 18 years).
People who believe their depression is caused by a chemical imbalance have worsened treatment outcomes.
There is still a lot we don’t know when it comes to the effect of SSRIs creating biochemical changes at the brain level.
Much of the success of antidepressants have been attributed to the placebo effect, especially after the advent of pharmaceutical marketing on TV ads. (Note on that – there is nothing wrong with placebos. If a placebo gets someone in a better mental state, I’m all for it. A placebo has the capability to impact health on a cellular level, so it’s not for nothing. But we also must weigh risks vs benefits to ensure the placebo isn’t causing more harm than good long-term).

Fortunately, there’s good news! Current research DOES support the neuroinflammatory model of depression (for now). We have much emerging research that shows that exercise, making anti-inflammatory dietary changes, and taking supplements, amino acids and even probiotics do impact the function of our neurotransmitters and brain-derived neurotrophic factor, which improves synaptic plasticity.

And as always, let me remind you that there is nothing to be ashamed of if you struggle with mental health or are on medication. That was me for so very long. I believed I was broken and my ONLY option was medication and more sleep. That couldn’t be further from the truth. Our brains can heal. Our bodies can heal. You can rise above the waves that threaten to take you under. There are so many evidence-based resources available for help. Please reach out if you’re struggling.

Please note: while I never encourage anyone to go on medication without the support of a trained psychiatrist, I also do not recommend anyone going off of meds without professional support. Research shows that hopping off meds cold turkey can be extremely dangerous. Withdrawal symptoms can occur for all of these drugs, whether through tapering or cold turkey. DO NOT DO THIS WITHOUT PROFESSIONAL SUPPORT.