Irene Bollettini1, Sara Poletti2, Clara Locatelli2, Benedetta Vai3, Enrico Smeraldi2, Cristina Colombo4, Francesco Benedetti5. 1. Department of Clinical Neurosciences, Scientific Institute and University Vita-Salute San Raffaele, Milan, Italy; C.E.R.M.A.C. (Centro di Eccellenza Risonanza Magnetica ad Alto Campo), University Vita-Salute San Raffaele, Milan, Italy; PhD Program in Philosophy and Sciences of Mind; University Vita-Salute San Raffaele, Milan, Italy. 2. Department of Clinical Neurosciences, Scientific Institute and University Vita-Salute San Raffaele, Milan, Italy; C.E.R.M.A.C. (Centro di Eccellenza Risonanza Magnetica ad Alto Campo), University Vita-Salute San Raffaele, Milan, Italy. 3. Department of Clinical Neurosciences, Scientific Institute and University Vita-Salute San Raffaele, Milan, Italy; C.E.R.M.A.C. (Centro di Eccellenza Risonanza Magnetica ad Alto Campo), University Vita-Salute San Raffaele, Milan, Italy; PhD Program in Evolutionary Psychopathology; Libera Università Maria SS. Assunta, Rome, Italy. 4. Department of Clinical Neurosciences, Scientific Institute and University Vita-Salute San Raffaele, Milan, Italy. 5. Department of Clinical Neurosciences, Scientific Institute and University Vita-Salute San Raffaele, Milan, Italy; C.E.R.M.A.C. (Centro di Eccellenza Risonanza Magnetica ad Alto Campo), University Vita-Salute San Raffaele, Milan, Italy. Electronic address: benedetti.francesco@hsr.it.
Abstract
BACKGROUND: Changes of white matter (WM) microstructure have been proposed as structural biomarkers of bipolar disorder (BD). The chronotherapeutic combination of repeated total sleep deprivation and morning light therapy (TSD+LT) can acutely reverse depressive symptoms in approximately 60% of patients, and it has been proposed as a model antidepressant treatment to investigate the neurobiological correlates of rapid antidepressant response. METHODS: We tested if baseline DTI measures can predict response to treatment in 70 in-patients affected by a major depressive episode in the course of BD, treated with chronotherapeutics for one week. We performed whole-brain tract-based spatial statistics with threshold-free cluster enhancement for the DTI measures of WM microstructure integrity: fractional anisotropy, axial, radial, and mean diffusivity. RESULTS: Increased mean and radial water diffusivity correlated with poor antidepressant response to TSD+LT in core WM tracts which are crucial for the functional integrity of the brain, including corpus callosum, corona radiata, cingulum bundle, superior longitudinal fasciculus, inferior fronto-occipital fasciculus, and thalamic radiation. LIMITATIONS: Limitations include issues such as generalizability, possible population stratification, medications and their effects on DTI measures, and no placebo control for chronotherapeutics. We could not consider other factors such as gene-environment interactions. CONCLUSIONS: The association of increased radial and mean diffusivity with poor response to chronotherapeutic treatment warrants interest for the study of DTI measures of WM microstructure as markers for treatment response in bipolar depression.
BACKGROUND: Changes of white matter (WM) microstructure have been proposed as structural biomarkers of bipolar disorder (BD). The chronotherapeutic combination of repeated total sleep deprivation and morning light therapy (TSD+LT) can acutely reverse depressive symptoms in approximately 60% of patients, and it has been proposed as a model antidepressant treatment to investigate the neurobiological correlates of rapid antidepressant response. METHODS: We tested if baseline DTI measures can predict response to treatment in 70 in-patients affected by a major depressive episode in the course of BD, treated with chronotherapeutics for one week. We performed whole-brain tract-based spatial statistics with threshold-free cluster enhancement for the DTI measures of WM microstructure integrity: fractional anisotropy, axial, radial, and mean diffusivity. RESULTS: Increased mean and radial water diffusivity correlated with poor antidepressant response to TSD+LT in core WM tracts which are crucial for the functional integrity of the brain, including corpus callosum, corona radiata, cingulum bundle, superior longitudinal fasciculus, inferior fronto-occipital fasciculus, and thalamic radiation. LIMITATIONS: Limitations include issues such as generalizability, possible population stratification, medications and their effects on DTI measures, and no placebo control for chronotherapeutics. We could not consider other factors such as gene-environment interactions. CONCLUSIONS: The association of increased radial and mean diffusivity with poor response to chronotherapeutic treatment warrants interest for the study of DTI measures of WM microstructure as markers for treatment response in bipolar depression.
Authors: Francesco Benedetti; Sara Poletti; Thomas A Hoogenboezem; Clara Locatelli; Oliver Ambrée; Harm de Wit; Annemarie J M Wijkhuijs; Elena Mazza; Chiara Bulgarelli; Benedetta Vai; Cristina Colombo; Enrico Smeraldi; Volker Arolt; Hemmo A Drexhage Journal: J Neuroimmune Pharmacol Date: 2016-04-23 Impact factor: 4.147
Authors: Martin J Lan; Harry Rubin-Falcone; Fatima Motiwala; Ying Chen; Jonathan W Stewart; David J Hellerstein; J John Mann; Patrick J McGrath Journal: Bipolar Disord Date: 2017-08-10 Impact factor: 6.744
Authors: Torbjørn Elvsåshagen; Linn B Norbom; Per Ø Pedersen; Sophia H Quraishi; Atle Bjørnerud; Ulrik F Malt; Inge R Groote; Lars T Westlye Journal: PLoS One Date: 2015-05-28 Impact factor: 3.240
Authors: M Berk; O Dandash; R Daglas; S M Cotton; K Allott; A Fornito; C Suo; P Klauser; B Liberg; L Henry; C Macneil; M Hasty; P McGorry; C Pantelis; M Yücel Journal: Transl Psychiatry Date: 2017-01-24 Impact factor: 6.222