Researchers uncovered an association between increases in cerebral blood flow and improvement in depressive symptoms in patients aged 50 years and older. The findings of their study were published in the Journal of Clinical Psychiatry.
The investigators used neuroimaging to examine relationships between late-life depression, cerebral blood flow, and white matter hyperintensities, hoping to add new, dynamic biomarkers to one that they identified in a previous study: blood-oxygen-level–dependent connectivity.
Participants (N=58) were recruited from the open-label phase of 2 clinical trials, had no history of mania or psychosis, and met the criteria for major depressive disorder according to the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition. Eligible participants scored at least 15 on the Montgomery-Asberg Depression Rating Scale. All data were collected between July 2011 and December 2015.
Participants underwent 5 magnetic resonance imaging (MRI) scans in Munich, Germany: at baseline, a day after placebo, a day after the first dose of the serotonin-norepinephrine reuptake inhibitor venlafaxine, a week after the first dose, and at the end of the 12-week trial.
Remission was defined as a depression rating score of less than 10 for 2 consecutive weeks. Of the 46 participants included in the final analysis, 24 met this criterion. Scans revealed significant differences between patients who achieved remission and patients who did not.
Analyses revealed a relationship between increased white matter hyperintensities and decreased cerebral blood flow, as well as improvement in depression symptom severity associated with a significant increase in cerebral blood flow in multiple brain structures. The directions of these relationships were not examined in this study.
No associations were identified between total changes in cerebral blood flow from baseline to end, remission status, venlafaxine serum levels, or baseline depression rating scores.
Because of the study’s relatively small sample size and number of dropouts (n=12), the findings should be interpreted with caution.
Wei W, Karim HT, Lin C, et al. Trajectories in cerebral blood flow following antidepressant treatment in late-life depression: support for the vascular depression hypothesis [published online October 23, 2018]. J Clin Psychiatry. doi:10.4088/JCP.18m12106