Patients who use certain types of prescribed steroids — including inhalers that treat asthma long-term — may experience changes to their brain’s structure and size, according to a new study.
These medications — glucocorticoids, a class of synthetic steroids — affect white and gray matter in the brain and might lead to neuropsychiatric effects, according to a study published in the medical research journal BMJ Open.
The study is the largest of its kind, and its results support earlier, smaller research findings.
Neuropsychiatric symptoms related to long-term use of such prescribed steroids may include:
The researchers — who acknowledge that the medications are “very effective” in treating a large variety of conditions — say that in the past, the use of systemic steroids (such as infusions and pills) and inhaled steroids also has been linked to metabolic, cardiovascular and musculoskeletal side effects.
As part of the recent study, researchers analyzed data from the UK Biobank on people ages 40 to 69.
The researchers looked at MRI brain scans of hundreds of people who use systemic or inhaled steroids. These scans were then compared with scans of thousands of people who do not use any steroids.
The brains of those who use systemic or inhaled steroids had less intact white matter than those of nonusers, the researchers found. The effects were greater in those who use systemic steroids than those who use inhaled steroids.
White brain matter is involved in connecting and signaling neurons (nerve cells).
According to a summary of the researchers’ findings from BMJ Open, which is published by the British Medical Association:
“Systemic [steroid] use was associated with a larger caudate compared with no use, while use of inhaled steroids was associated with a smaller amygdala. Both the caudate and amygdala are grey matter structures in the brain involved in cognitive and emotional processing.”
In addition, the researchers say that:
- Those who used systemic steroids showed reduced processing speed compared with nonusers, and were much more likely to report depressive symptoms, apathy, restlessness, fatigue and lethargy.
- Inhaled steroid users reported more tiredness and lethargy than nonusers. In addition, the symptoms they experienced were more modest than those of systemic steroid users.
The researchers did sound a note of caution about the findings, saying that although a causal relationship between steroid use and brain changes is likely, a formal conclusion about a direct, cause-and-effect relationship cannot be established from the study.
In addition, CNN warns people not to mistake glucocorticoid inhalers for the type of quick-relief inhalers used to stop an asthma attack. According to CNN:
“Quick-relief inhalers contain non-steroid medications that relax the muscles in the lungs, such as albuterol, levalbuterol and pirbuterol, which can open airways in minutes. Inhaled corticosteroids do not work in emergencies — they are prescribed for longer-term control of inflammatory conditions.”