Altered effective connectivity in sensorimotor cortices is a signature of severity and clinical course in depression
Fecha
2021Autor
Ray, Dipanjan
Bezmaternykh, Dmitry
Mel’nikov, Mikhail
Friston, Karl J.
Das, Moumita
Metadatos
Mostrar el registro completo del ítem
Altered effective connectivity in sensorimotor cortices is a signature of severity and clinical course in depression Dipanjan Ray, Dmitry Bezmaternykh, Mikhail Mel’nikov, Karl J. Friston, Moumita Das Proceedings of the National Academy of Sciences Oct 2021, 118 (40) e2105730118; DOI: 10.1073/pnas.2105730118
Resumen
Functional neuroimaging research on depression has traditionally
targeted neural networks associated with the psychological
aspects of depression. In this study, instead, we focus on alterations
of sensorimotor function in depression. We used restingstate
functional MRI data and dynamic causal modeling (DCM)
to assess the hypothesis that depression is associated with aberrant
effective connectivity within and between key regions in the
sensorimotor hierarchy. Using hierarchical modeling of betweensubject
effects in DCM with parametric empirical Bayes we first
established the architecture of effective connectivity in sensorimotor
cortices.We found that in (interoceptive and exteroceptive)
sensory cortices across participants, the backward connections are
predominantly inhibitory, whereas the forward connections are
mainly excitatory in nature. In motor cortices these parities were
reversed. With increasing depression severity, these patterns are
depreciated in exteroceptive and motor cortices and augmented
in the interoceptive cortex, an observation that speaks to depressive
symptomatology. We established the robustness of these
results in a leave-one-out cross-validation analysis and by reproducing
the main results in a follow-up dataset. Interestingly, with
(nonpharmacological) treatment, depression-associated changes
in backward and forward effective connectivity partially reverted
to group mean levels. Overall, altered effective connectivity in
sensorimotor cortices emerges as a promising and quantifiable
candidate marker of depression severity and treatment response.