Associations Among Suicidal Ideation, White Matter Integrity and Cognitive Deficit in First-Episode Schizophrenia.

Yicheng Long,Xuan Ouyang,Eric Y H Chen,Xinran Hu,Xudong Chen,Weidan Pu,Robert M Rohrbaugh,Edwin Lee,Baoci Shan,Zhening Liu

doi:10.3389/fpsyt.2018.00391

Abstract

Objective: The study was aimed to investigate the possible associations among suicidal ideation, brain white matter (WM) integrity and cognitive deficit in first-episode schizophrenia (FES) using diffusion tensor imaging.Methods: The sample contained 18 FES patients with suicidal ideation (SI+), 45 FES patients without suicidal ideation (SI–) and 44 healthy controls. The Calgary Depression Scale for Schizophrenia was used to measure the suicidal ideation and depression symptoms. The whole brain WM integrity and three domains of cognitive function: working memory, verbal comprehension as well as processing speed were compared between the three groups.Results: Compared with SI–, SI+ showed preserved WM integrity as indicated by significantly higher factional anisotropy (FA) or lower mean diffusivity (MD) in multiple WM tracts, and higher FA coupled with lower MD in bilateral posterior corona radiata. Compared with SI−, SI+ were more depressed and had less cognitive deficit in working memory and verbal comprehension. The fiber tracts in bilateral posterior corona radiata connect to the precuneus as shown by probabilistic tractography, and their WM integrity disruptions were found to be positively associated with the cognitive deficits in the FES patients.Discussion: Preserved WM integrity may be a risk factor for suicidal ideation in FES patients. One possible explanation is that it contributes to preserved cognitive function, especially in working memory and verbal comprehension, which may be associated with greater insight and could lead to increased depression and suicidal ideation. The posterior corona radiata and the precuneus may be linked to the related biological processes.

Highlights

Suicide is a complex process ranging from suicidal ideation to planning, attempting and committing suicide [1]
Among first-episode schizophrenia (FES) patients with (SI+, n = 18)/without (SI, n = 45) current suicidal ideation and healthy controls (HC, n = 44), no significant between-group differences were observed in age, gender, education level, Scale for Assessment of Positive Symptoms (SAPS)/Scale for the Assessment of Negative Symptoms (SANS) total scores, course of disease or the dosage of antipsychotics
We found that compared with the FES patients without current suicidal ideation (SI–), the patients with current suicidal ideation (SI+) showed [1] greater white matter (WM) integrity, indicated by significantly higher Factional anisotropy (FA) or lower mean diffusivity (MD) in multiple WM tracts and higher FA coupled with lower MD in two clusters located in bilateral posterior corona radiata; [2] less cognitive deficit in working memory and verbal comprehension

Summary

Introduction

Suicide is a complex process ranging from suicidal ideation to planning, attempting and committing suicide [1]. It was reported that approximately 20–40% schizophrenia patients attempt and 5.6% commit suicide in their lifetime [2,3,4,5]. Several functional and structural neuroimaging studies have attempted to find possible associations between brain characteristics and suicidality in schizophrenia, referring to both brain gray matter and white matter (WM) [7,8,9,10,11]. Diffusion tensor imaging (DTI) offers a powerful tool to assess the microstructural integrity of brain WM [12]. To our knowledge, no study has focused on the associations between WM integrity and suicidal ideation in schizophrenia

Methods

Results

Conclusion