In animals, stress and corticosteroids can be associated with both reversible and irreversible changes in the hippocampus. Changes in memory and hippocampal structure, perhaps in part due to cortisol elevations, are reported in some patients with mood disorders. Minimal data are available on the effects of long-term exposure to corticosteroids on the human hippocampus. We previously reported greater depressive symptom severity, poorer memory and smaller hippocampal volumes in patients with asthma or rheumatic diseases receiving long-term prednisone therapy than in controls.
In this report, patients and controls were assessed a mean of 4 years after the first assessment to determine if depressive and manic symptoms and cognition remained stable, improved or worsened. Seven prednisone-treated patients and six controls were identified and agreed to reassessment with psychiatric symptom and neurocognitive measures. Follow-up MRIs for hippocampal volume analysis were available for two prednisone-treated participants.
With the exception of an increase in depressive symptoms in those receiving prednisone, participants and controls did not show significant change in mood or cognition from the initial assessment. One participant discontinued prednisone and showed improvement in psychiatric symptoms and cognition. Hippocampal volumes were available in two prednisone-treated participants and showed inconsistent findings.
A limitation is the small sample size.
Our findings, although preliminary in nature, suggest that long-term prednisone therapy is associated with initial changes in mood, memory and hippocampal volume that appear to stabilize over time.