Do Steroids Used for Asthma and Allergies Change Brain Structures?

Glucocorticoids have been used for decades to treat many different medical conditions including asthma and allergies. However, they have multiple side effects. One of these side effects are changes in brain structures, but what does that mean for you?

What are glucocorticoids (ie. steroids)?

Glucocorticoids are a group of medications that are synthetic versions of the body’s natural cortisol. Cortisol is a potent anti-inflammatory and is crucial for many biologic functions. However, an excess of cortisol as in certain diseases (ie. Cushing’s disease) or the chronic use of glucocorticoids is associated with negative effects.

Can oral glucocorticoids alter brain structures?

In a recent study published in the British Medical Journal, researchers noted a decrease in the white matter of the brain in patients taking chronic oral glucocorticoids. This portion of the brain contains axons which are the projections from neurons that send messages to other parts of the body.

It was also found that these changes were more pronounced with higher doses and longer durations of treatment in patients taking oral glucocorticoids.

Additionally, oral glucocorticoids users were found to experience more depression, disinterest, tenseness, and tiredness.

What about inhaled glucocorticoids?

This study did not find significant changes when evaluating inhaled glucocorticoids (steroid inhalers). This is likely due to the fact that less steroid reaches the bloodstream when inhaled.

Additionally, it did not find an increase in depression, disinterest, and tenseness in patients using inhaled steroids. However, these patients did experience tiredness more than people not using the inhaled steroids.

What does all this mean?

The findings in this study are not new and have been known for many years. One important finding of this study was that these changes did not have a significant effect on cognitive function.

Additionally, it confirmed that inhaled steroids are safer than oral. Their adverse effects on the brain were not as significant. Supporting the fact that fewer glucocorticoids enter the bloodstream when used in inhalers.

Importantly, this article did highlight the fact that glucocorticoids are associated with psychiatric symptoms such as depression, mania, delirium, and suicide attempts. Also, the changes in the brain may be behind the occurrence of these adverse effects.

Should you stop taking steroids?

No. For many conditions, steroids are crucial for proper treatment. However, when on these medications healthcare professionals and patients should be aware and watchful for their psychiatric side effects.

It is important to use these medications for the shortest duration and at the lowest dose possible to treat your medical conditions. Talk with your doctor or pharmacist if you have any concerns regarding your medications. In addition, they can also help determine if another medication or lower dose of steroids is appropriate.

Do not stop taking these medications on your own.


Glucocorticoids have been known to cause changes in brain structures, especially oral forms. These changes are greater with higher doses and longer use. When on these medications, psychiatric adverse effects can be seen and should be monitored and reported if experienced.

However, these medications are sometimes the best option to treat certain conditions and thus should not be avoided.

Key takeaways

Glucocorticoid medications can produce alterations in brain structures which have been known for years.

The changes in brain structure may explain why these medications cause psychiatric adverse effects such as depression and mania.

Talk to your doctor to see if there are other options to treat your condition and that you are taking the lowest dose necessary.

Do not stop taking glucocorticoids unless under the direction of your physician.


British Journal of Medicine. Association between use of systemic and inhaled glucocorticoids and changes in brain volume and white matter microstructure: a cross-sectional study using data from the UK Biobank.