Individuals diagnosed with major depressive disorder (MDD) present with accelerated aging of certain brain structures such as the putamen. Published in Journal of Psychiatry & Neuroscience, the study was led and co-authored by Dr Sacchet at the Department of Psychology, Stanford University.
The putamen, together with the caudate nucleus and globus pallidus, represents a part of the basal ganglia. The relationship between the basal ganglia and cognitive and behavioral symptoms observed in patients with depression has been known for some time. For example, it has been reported that patients with MDD have diminished putamen volumes compared with those of typical, healthy controls.
In the current study, investigators recruited 232 individuals aged 18-60 years (116 were patients with MDD) to estimate grey matter volumes of the basal ganglia, including the nucleus accumbens, caudate, pallidum, and putamen. Two groups of participants did not differ with regard to sex distribution or educational attainment. In this sample, income was significantly lower in the group of participants with MDD; however, income was not significantly correlated with basal ganglia volumes. Clinical diagnosis was determined using the Structured Clinical Interview for DSM-IV, and the severity of depression was assessed using the Beck Depression Inventory (BDI).
Findings indicate that greater age-related decreases in volume of the putamen were observed in participants diagnosed with MDD compared with those of controls. “Although the volume of the putamen decreased with age in both the MDD and the control groups, this volumetric reduction occurred at a faster rate in the MDD group,” the authors wrote in their publication. The length of MDD history, or the duration of current depressive episode, was not associated with putamen volume. Similarly, the use of medications, or comorbid anxiety, was not associated with volumetric reductions in the basal ganglia.
“Accelerated aging [of the putamen] in individuals with MDD may be associated with reward-related abnormalities,” and these findings “underscore the importance of early detection and treatment of this chronic and prevalent disorder,” the authors concluded.
Sacchet MD, Camacho MC, Livermore EE, et al. Accelerated aging of the putamen in patients with major depressive disorder. J Psychiatry Neurosci. 2016;42(1):160010.