Impaired cerebro-cerebellar white matter connectivity and its associations with cognitive function in patients with schizophrenia.

Schizophrenia is a complex brain disorder of unknown etiology. Based on the notion of "cognitive dysmetria," we aimed to investigate aberrations in structural white matter (WM) connectivity that links the cerebellum to cognitive dysfunction in patients with schizophrenia. A total of 112 participants (65 patients with schizophrenia and 47 healthy controls [HCs]) were enrolled and underwent diffusion tensor imaging. Between-group voxel-wise comparisons of cerebellar WM regions (superior/middle [MCP]/inferior cerebellar peduncle and pontine crossing fibers) were performed using Tract-Based Spatial Statistics. Cognitive function was assessed using the Trail Making Test Part A/B (TMT-A/B), Wisconsin Card Sorting Test (WCST), and Rey-Kim Memory Test in 46 participants with schizophrenia. WM connectivity, measured as fractional anisotropy (FA), was significantly lower in the MCP in participants with schizophrenia than in HCs. The mean FAs extracted from the significant MCP cluster were inversely correlated with poorer cognitive performance, particularly longer time to complete the TMB-B (r = 0.559, p < 0.001) and more total errors in the WCST (r = 0.442, p = 0.003). Our findings suggest that aberrant cerebro-cerebellar communication due to disrupted WM connectivity may contribute to cognitive impairments, a core characteristic of schizophrenia. Our results may expand our understanding of the neurobiology of schizophrenia based on the cerebro-cerebellar interconnectivity of the brain.

Intra-individual variability in neurocognitive function in schizophrenia: relationships with the corpus callosum.

Patients with schizophrenia not only have impairments in neurological function, but also have instability and variability in neurocognitive function. However, previous researchers have not fully studied the relationships between dispersion across multiple neurocognitive domains and white matter (WM) structures of the brain. This study focuses on intra-individual variability (IIV) in patients with schizophrenia and its relationship with WM integrity of the corpus callosum (CC). Thirty-eight patients with schizophrenia were enrolled in the study. All subjects underwent assessments of neurocognitive function using the Korean-Wechsler Adult Intelligence Scale-Revised (K-WAIS-R) and the severity of clinical symptoms using the Positive and Negative Syndrome Scale (PANSS). IIV across subtests of the K-WAIS-R was calculated using the Holtzer's equation. Tract-based spatial statistics were used to analyze diffusion tensor images. In subjects with schizophrenia, a negative correlation was found between IIV in performance intelligence quotient (PIQ) and fractional anisotropy (FA) values in the genu of the CC. In addition, FA values of the same region were negatively correlated with the total and subscale scores of positive symptoms and general psychopathology from the PANSS. Our findings suggest that the genu of the CC may play an important role in IIV in PIQ and symptomatology in patients with schizophrenia.

Relationship between burnout and PTSD symptoms in firefighters: the moderating effects of a sense of calling to firefighting.

PURPOSE: Firefighting has been reported to lead to burnout and posttraumatic stress disorder (PTSD). However, burnout and PTSD symptoms may vary depending on personal characteristics, such as having a sense of calling. This study examined the role of calling in the association between burnout and PTSD symptoms. We hypothesized that burnout would be associated with more severe PTSD symptoms and calling would buffer the relationship between burnout and PTSD symptoms. METHODS: The Korean version of the Maslach Burnout Inventory-General Survey, Sense of Calling Subscale of the Professionalism Scale, and the Impact of Event Scale-Revised-Korean version were used to measure burnout, calling, and PTSD symptoms. Data from 109 of 127 firefighters from Gyeonggi-do, South Korea were analyzed using hierarchical linear regression. RESULTS: Burnout was a significant predictor of PTSD symptoms. Furthermore, the interaction term between burnout and calling accounted for a significant variance in PTSD symptoms. Higher burnout was associated with severe PTSD symptoms, but this relationship differed by the level of calling. The increase in PTSD symptoms due to increased burnout in the high calling group was relatively higher than in the low and average calling groups. CONCLUSIONS: Calling, though perceived as a positive variable, can be hazardous to exhausted people. A sense of calling as part of one's job identity should not be encouraged until personal circumstances and characteristics, such burnout symptoms, are evaluated. Identifying context and variables associated with PTSD for interventions with firefighters and persons in other dangerous occupations should aid in their recovery from trauma exposure.

Underestimating the severity of bipolar depression: a comparison of the Hamilton Depression Rating Scale items.

BACKGROUND: The Hamilton Depression Rating Scale (HDRS) is a clinician-rated instrument to assess the severity of depressive symptoms that does not account for the differences between bipolar (BP) and unipolar (UP) disorders. This study attempts to evaluate differences in the total scores of the HDRS, Beck Depression Inventory (BDI), and Global Assessment of Functioning (GAF) ratings of patients with bipolar II (BP-II) and UP depression. Each factor and item of the HDRS was compared between the two groups in order to identify specific symptoms. METHODS: 588 patients with bipolar II disorder (n=101) and major depressive disorder (n=487) were enrolled in this study. All participants completed the BDI and individually interviewed using HDRS. Each participant was also evaluated with regard to global functioning. RESULTS: The BP group scored lower on the total HDRS and all of the factors. The BP and UP groups did not differ in terms of BDI and GAF. With regard to the individual items of HDRS, the BP group scored lower on items associated with 'Depressed mood', 'Work and interest', 'Somatic, gastro', and 'Hypochondriasis'. LIMITATIONS: There was a significant age differences between the two groups. CONCLUSIONS: The results of this study suggest that the severity of bipolar depression may be less well-recognized by the HDRS due to the different presentations of depressive symptoms. Thus, the clinician should be careful not to underestimate the sincerity of patients' reports when evaluating depression.