Photo Credit: Sasithorn Phuapankasemsuk
The following is a summary of “Monoaminergic network dysfunction and development of depression in multiple sclerosis: a longitudinal investigation,” published in the December 2023 issue of Neurology by Mstri et al.
Prior research linked low mood in Multiple Sclerosis (MS) to disrupted brain networks of mood-regulating chemicals, but long-term evidence was missing.
Researchers conducted a retrospective study on how brain networks’ resting-state functional connectivity (RS FC) within mood-regulating pathways change over time in MS patients who develop depression.
They conducted assessments on 49 MS patients without depression (Montgomery–Asberg Depression Scale, MADRS ≤ 9) and 27 HCs at baseline and after a median follow-up of 1.6 years (interquartile range 1.0–2.1 years) using clinical and 3.0 T RS FC evaluations. Monoamine-related RS FC was derived based on independent component analysis and constrained to PET atlases for dopamine, noradrenaline, and serotonin transporters. Studied how resting-state functional connectivity in monoaminergic networks changes over time and its correlation with MADRS scores.
The results showed MS patients exhibited decreased RS FC compared to healthy controls in all PET-guided monoaminergic networks in frontal, cingulate, and cerebellar cortices, with increased RS FC in parieto-occipital regions. Among MS patients, 29% (14) developed depressive symptoms (MADRS > 9) at follow-up (D-MS), showing widespread RS FC decrease over time in the PET-guided dopamine network, mainly in orbitofrontal, occipital, anterior cingulate, and precuneal cortices compared to those who did not develop depressive symptoms. In D-MS, decreased RS FC over time was also observed in parahippocampal and occipital regions of the PET-guided noradrenaline network. The longitudinal decrease in RS FC in dopamine and noradrenaline PET-guided networks correlated with increased MADRS scores (r = range −0.65/ −0.61, P<0.001).
They concluded that tracing RS FC changes in MS patients revealed specific alterations in dopamine and noradrenaline networks linked to later depression onset.
Source: link.springer.com/article/10.1007/s00415-023-12138-7
