Well-Being Prevention & Cures

Study links common asthma medication to changes in brain

“Since these medications are widely used, awareness of these associations is necessary across medical specialties and research into alternative treatment options is warranted.”

Story at a glance


  • A new study conducted among UK Biobank participants revealed an association between changes in brain structure and glucocorticoid use.

  • Results suggest longer use of these medications may be linked with more significant changes.

  • Patients with a variety of diseases or ailments take these steroids to suppress their immune systems.

A new study published in The BMJ found a link between systemic and inhaled glucocorticoids— medications commonly taken for asthma and chronic obstructive pulmonary disease (COPD)— and structural and volume changes in brain gray and white matter. 

Results are based on a cross-sectional study conducted among 779 individuals who took the medications and 24,106 controls enrolled in the UK Biobank between 2006 and 2010. 

Of the patients included in the biobank, 222 used systemic glucocorticoids and 557 took inhaled glucocorticoids. Systemic glucocorticoids are taken either orally or with an injection.

“Both systemic and inhaled glucocorticoid use are associated with decreased white matter integrity and limited changes in [gray matter volume],” researchers wrote. White matter plays a role in neuronal connectivity and brain signaling, they added.


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“This association may contribute to the neuropsychiatric side effects of glucocorticoid medication, especially with chronic use.”

Those who took systemic steroids performed worse on a processing speed test compared with controls, and reported more depressive symptoms, apathy, and restlessness than non-users. 

Long-term use of these medications has previously been associated with anxiety, depression, mania, and delirium. The current study marks the largest of its kind, while the drugs assessed are widely used to treat a variety of conditions, thanks to their immunosuppressive properties.

All study participants underwent diffusion tensor imaging (DTI) and magnetic resonance imaging (MRI), were mainly in their 60s, and had no history of psychiatric disorders. 

Associations between less intact white matter structure were greater among systemic users compared with inhaled glucocorticoid users. Data also showed effects might be greater among long-term users.

Systemic use was also associated with a larger caudate compared with controls. However, inhaled users exhibited a smaller amygdala on average. The caudate and amygdala are gray matter structures involved in cognitive and emotional processing, researchers explained. 

“Although a causal relation between glucocorticoid use and changes in the brain is likely based on the present and previous studies, the cross-sectional nature of this study does not allow for formal conclusions on causality,” they cautioned. 

Mood changes were also only assessed during a window of the previous two weeks, while changes might have been linked with the condition for which a patient received the medication, not the steroid itself. 

“Since these medications are widely used, awareness of these associations is necessary across medical specialties and research into alternative treatment options is warranted,” authors concluded.