Delineation of early and later adult onset depression by diffusion tensor imaging.

Yuqi Cheng,Yuqi Cheng,Fang Liu,Fang Liu,Binbin Nie,Binbin Nie,Lin Xu,Lin Xu,Na Li,Na Li,Baoci Shan,Baoci Shan,Chunrong Luo,Jian Xu,Jian Xu,Hongjun Yu,Yan Bai,Yan Bai,Haijun Li,Xiufeng Xu,Xiufeng Xu,Yiru Fang

doi:10.1371/journal.pone.0112307

Abstract

BackgroundDue to a lack of evidence, there is no consistent age of onset to define early onset (EO) versus later onset (LO) major depressive disorder (MDD). Fractional anisotropy (FA), derived from diffusion tensor imaging (DTI), has been widely used to study neuropsychiatric disorders by providing information about the brain circuitry, abnormalities of which might facilitate the delineation of EO versus LO MDD.MethodIn this study, 61 pairs of untreated, non-elderly, first-episode MDD patients and healthy controls (HCs) aged 18–45 years old received DTI scans. The voxel-based analysis method (VBM), classification analysis, using the Statistical Package for the Social Sciences (SPSS), and regression analyses were used to determine abnormal FA clusters and their correlations with age of onset and clinical symptoms.ResultsClassification analysis suggested in the best model that there were two subgroups of MDD patients, delineated by an age of onset of 30 years old, by which MDD patients could be divided into EO (18–29 years old) and LO (30–45 years old) groups. LO MDD was characterized by decreased FA, especially in the white matter (WM) of the fronto-occipital fasciculus and posterior limb of internal capsule, with a negative correlation with the severity of depressive symptoms; in marked contrast, EO MDD showed increased FA, especially in the WM of the corpus callosum, corticospinal midbrain and inferior fronto-occipital fasciculus, while FA of the WM near the midbrain had a positive correlation with the severity of depressive symptoms.ConclusionSpecific abnormalities of the brain circuitry in EO vs. LO MDD were delineated by an age of onset of 30 years old, as demonstrated by distinct abnormal FA clusters with opposite correlations with clinical symptoms. This DTI study supported the evidence of an exact age for the delineation of MDD, which could have broad multidisciplinary importance.Trial RegistrationClinicalTrials.gov NCT00703742

Highlights

Major depressive disorder (MDD) is well known for its clinical heterogeneity, including variability in the age of onset, constellations of depressive symptoms, and disease severity and course [1]
Classification analysis suggested in the best model that there were two subgroups of major depressive disorder (MDD) patients, delineated by an age of onset of 30 years old, by which MDD patients could be divided into early onset (EO) (18–29 years old) and later onset (LO) (30–45 years old) groups
LO MDD was characterized by decreased Fractional anisotropy (FA), especially in the white matter (WM) of the fronto-occipital fasciculus and posterior limb of internal capsule, with a negative correlation with the severity of depressive symptoms; in marked contrast, EO MDD showed increased FA, especially in the WM of the corpus callosum, corticospinal midbrain and inferior fronto-occipital fasciculus, while FA of the WM near the midbrain had a positive correlation with the severity of depressive symptoms

Summary

Results

Clinical data Sixty-eight MDD patients who met the inclusion and exclusion criteria received DTI scans. MDD subgroups A voxel-based analysis method (VBM) for diffusion tensor imaging (DTI) was used to identify abnormal FA clusters in MDD patients vs HCs. When sixty-one pairs of participants between 18 and 45 years old were collected, we found a pattern of two clusters with decreased FA located in the right temporal lobe (RTEMP) and right middle frontal lobe (RMFG), while one cluster with increased FA was in the left occipital lobe (LOCG) (Figure 1A). When sixty-one pairs of participants between 18 and 45 years old were collected, we found a pattern of two clusters with decreased FA located in the right temporal lobe (RTEMP) and right middle frontal lobe (RMFG), while one cluster with increased FA was in the left occipital lobe (LOCG) (Figure 1A) We suspected that this result might have been only the average effect of MDD without considering different ages of onset in the effects on different patterns of significant FA clusters. In EO MDD, the FA values of the cluster in the left inferior longitudinal fasciculus near the parahippocampal gyrus decreased obviously wherever they were positively correlated with HDRS scores (Figure S3 in File S1)

Conclusion

Introduction

Materials and Methods

Discussion