Microstructural white matter changes are correlated with the stage of psychiatric illness

Abstract

Microstructural white matter changes have been reported in the brains of patients across a range of psychiatric disorders. Evidence now demonstrates significant overlap in these regions in patients with affective and psychotic disorders, thus raising the possibility that these conditions share common neurobiological processes. If affective and psychotic disorders share these disruptions, it is unclear whether they occur early in the course or develop gradually with persistence or recurrence of illness. Utilisation of a clinical staging model, as an adjunct to traditional diagnostic practice, is a viable mechanism for measuring illness progression. It is particularly relevant in young people presenting early in their illness course. It also provides a suitable framework for determining the timing of emergent brain alterations, including disruptions of white matter tracts. Using diffusion tensor imaging, we investigated the integrity of white matter tracts in 74 patients with sub-syndromal psychiatric symptoms as well as in 69 patients diagnosed with established psychosis or affective disorder and contrasted these findings with those of 39 healthy controls. A significant disruption in white matter integrity was found in the left anterior corona radiata and in particular the anterior thalamic radiation for both the patients groups when separately contrasted with healthy controls. Our results suggest that patients with sub-syndromal symptoms exhibit discernable early white matter changes when compared with healthy control subjects and more significant disruptions are associated with clinical evidence of illness progression.

Challenges and developments in research of the early stages of bipolar disorder

“…70 Collectively, these results are consistent with the notion that BD is associated with discernable abnormalities in white-matter integrity, and that this is driven predominantly by the BD I phenotype. 70 Another recent study that assessed white-matter microstructure and grey-matter volumes in a community sample of adolescents with BD found widespread alterations in white matter involving a number of tracts that continue to mature during adolescence. 71 In addition, the authors observed that BD in adolescents is associated with structural connectivity alterations likely to affect the development of white-matter bundles and connected grey-matter areas involved in emotion regulation.…”

“…70 Specifically, this study provided evidence of microstructural whitematter changes within the corpus callosum early in the course of illness. 70 The nature of these changes suggests an association with abnormalities in axon myelination. 70 Collectively, these results are consistent with the notion that BD is associated with discernable abnormalities in white-matter integrity, and that this is driven predominantly by the BD I phenotype.…”

“…70 The nature of these changes suggests an association with abnormalities in axon myelination. 70 Collectively, these results are consistent with the notion that BD is associated with discernable abnormalities in white-matter integrity, and that this is driven predominantly by the BD I phenotype. 70 Another recent study that assessed white-matter microstructure and grey-matter volumes in a community sample of adolescents with BD found widespread alterations in white matter involving a number of tracts that continue to mature during adolescence.…”

“…69 To date, most studies of white-matter changes in BD have been conducted in older subjects and those with wellestablished disorders. 70 A recent study reported significant changes in major white-matter tracts in a large cohort of young patients in the early stages of BD. 70 Specifically, this study provided evidence of microstructural whitematter changes within the corpus callosum early in the course of illness.…”

“…70 A recent study reported significant changes in major white-matter tracts in a large cohort of young patients in the early stages of BD. 70 Specifically, this study provided evidence of microstructural whitematter changes within the corpus callosum early in the course of illness. 70 The nature of these changes suggests an association with abnormalities in axon myelination.…”