Move away from ‘one dose for all’?
Another surprise was that the results showed no hippocampal volume differences with steroid use, Dr. Meijer noted.
The modest association between glucocorticoid use and brain volumes could indicate that white matter integrity is more sensitive to glucocorticoids than is grey matter volume, “at least at the structural level,” he said.
He added that longer use or higher doses may be necessary to also induce volumetric changes.
Participants also completed a questionnaire to assess mood over the previous 2 weeks. Systemic glucocorticoid users had more depressive symptoms, disinterest, tenseness/restlessness, and tiredness/lethargy, compared with the control group. Inhaled glucocorticoid users only reported more tiredness/lethargy.
The investigators note that mood-related effects could be linked to the condition for which glucocorticoids were prescribed: for example, rheumatoid arthritis or chronic obstructive pulmonary disease.
In terms of cognition, systemic glucocorticoid users performed significantly worse on the symbol digit substitution task, compared with participants in the control group.
In light of these findings, pharmaceutical companies that make inhaled corticosteroids “should perhaps find out if glucocorticoids can be dosed by kilogram body weight rather than simply one dose fits all,” which is currently the case, Dr. Meijer said.
Impressive, but several limitations
Commenting on the findings, E. Sherwood Brown, MD, PhD, Distinguished Chair in Psychiatric Research and professor and vice chair for clinical research, department of psychiatry, The University of Texas Southwestern Medical Center, Dallas, called the study sample size “impressive.”
In addition, the study is the first to look at systemic as well as inhaled corticosteroids, said Dr. Brown, who was not involved with the research. He noted that previously, there had been only case reports of psychiatric symptoms with inhaled corticosteroids.
That results are in the same direction but greater with systemic, compared with inhaled corticosteroids, is “particularly interesting” because this might suggest dose-dependent effects, Dr. Brown said.
He noted that cognitive differences were also only observed with systemic corticosteroids.
Some study observations, such as smaller amygdala volume with inhaled but not systemic corticosteroids, “are harder to understand,” said Dr. Brown.
However, he pointed out some study limitations. For example, data were apparently unavailable for verbal and declarative memory test data, despite corticosteroids probably affecting the hippocampus and causing memory changes.
Other drawbacks were that the dose and duration of corticosteroid use, as well as the medical histories of study participants, were not available, Dr. Brown said.
No study funding was reported. Dr. Meijer has received research grants and honorariums from Corcept Therapeutics and a speakers’ fee from Ipsen. Dr. Brown is on an advisory board for Sage Pharmaceuticals, which is developing neurosteroids (not corticosteroids) for mood disorders. He is also on a Medscape advisory board related to bipolar disorder.
A version of this article first appeared on Medscape.com.