Steroids are linked to changes in gray and white matter in the brain. A study compared MRI scans of people who took corticosteroids with people who did not. It found changes in brain structure. These changes help explain the mood swings, depression and weaker thinking skills tied to long steroid use.
Summary: Corticosteroids are among the most common drugs. Doctors use them for many problems, from pain and inflammation to allergies and autoimmune disorders (where the body attacks itself). But long use also brings many side effects. These include a higher risk of mood swings, depression, weaker thinking, and more. A new study compared MRI brain scans of steroid users with non-users. It found that these mental health effects come from changes in brain structure caused by long steroid use.
Steroids are among the most common drugs for pain and inflammation. They are also among the most common drugs for allergies and autoimmune diseases. Often, people have to take steroids nonstop for years to keep their disease in check. Here we mean corticosteroids, not androgens, which are drugs that boost performance. The body makes many steroid hormones that do many jobs. Sex hormones are not the only steroids. Corticosteroids are built much like the hormones the adrenal gland makes.
Corticosteroids are the drugs of choice for severe asthma, autoimmune disorders, and even chronic pain. Doctors may prescribe them to inhale or to take by mouth. These drugs are fairly safe when inhaled. But with long use, both forms have similar side effects. Common ones are more infections, water retention, high blood pressure, mood swings, behavior changes, upset stomach, weight gain, and more. Doctors have long known these side effects. Still, they have to prescribe these drugs for many diseases. There are no other options.
For example, inhaled corticosteroids are the best treatment for many asthma patients. Doctors may also need corticosteroids to manage long-term swelling and inflammation. Doctors have long known that corticosteroids cause mood swings, anxiety, depression, mania, and other mental health problems. But they did not know why. Was it a change in metabolism, in hormones, in brain chemicals, or something else? Now a study shows that these mental health problems likely come from changes in brain structure caused by long corticosteroid use.
In the new study, researchers used the UK Biobank. It holds data from more than half a million adults aged 40 to 69 years. Researchers looked at brain scans of 222 people taking systemic (whole-body) steroids. They also looked at 557 people using inhaled steroids. They compared these scans with those of 24,106 people who did not use steroids.
The study found that both inhaled and systemic steroid use were linked to changes in brain structure. Users had less white and gray matter. That means long steroid use weakens the links between brain cells. White matter was hit hardest in long-term users. As you might expect, the damage was worse in people who took steroids by mouth than in people who inhaled them.
The study also found that systemic steroid use led to a larger caudate. Inhaled steroids led to a smaller amygdala. Both of these brain parts play key roles in thinking and handling emotion. In systemic steroid users, these brain changes also came with worse signs of depression, fatigue, restlessness, and apathy (not caring).
It is among the first studies to show that long corticosteroid use changes the brain’s structure. That leads to mental and mood side effects. The study also found these side effects are common with both oral and inhaled forms. These drugs are widely used, and in many diseases nothing can replace them. So researchers say we urgently need safer options than synthetic corticosteroids.
Frequently asked questions
What damage do long-term steroids do to the brain?
Long-term corticosteroid use changes the structure of the brain. The study used UK Biobank MRI scans. People taking steroids had less white and gray matter than non-users. That means brain cells were less well linked. White matter took the biggest hit. The damage was worse in people taking steroids by mouth than in people using inhalers.
What are the mental side effects of steroids?
Doctors have long seen corticosteroids cause mood swings, anxiety, depression, mania and behavior changes. In the MRI study, people on systemic (whole-body) steroids also showed worse signs of depression, fatigue, restlessness and apathy. Those symptoms lined up with changes in brain structure you can measure. So they are not just a matter of attitude or stress.
Can steroids affect your thinking?
Yes. Long steroid use is linked to weaker thinking. The study found that systemic steroids enlarged the caudate. Inhaled steroids shrank the amygdala. Both regions help the brain think and handle emotion. A change in their size gives a physical reason for the thinking and mood problems doctors have seen for years.
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