Even euthymic patients with bipolar disorder may be impaired in advanced ToM tasks. Executive dysfunction and some other cognitives deficits such as basic emotion recognition may be at least partly responsible for this result.
Researchers have reported that serum brain-derived neurotrophic factor (sBDNF) of drug-free depressed patients are lower than those of healthy controls and proposed that low sBDNF levels might reflect failure of neuronal plasticity in depression. In this study, we compared sBDNF levels of depressed patients (n = 28) before and after 8 weeks of antidepressant treatment, with those of healthy controls (n = 18) to test the hypothesis that initially low sBDNF levels of drug-free depressed patients will increase parallel with their clinical response to antidepressant treatment. The severity of depression and response to treatment were assessed with Hamilton Rating Scale for Depression (HAM-D). sBDNF was assayed with the sandwich ELISA method. Baseline sBDNF levels of patients (mean, 20.8 ng/ml; [S.D., 6.7]) were significantly lower than those of controls (mean, 26.8 ng/ml; [S.D., 9.3]; p = 0.015), and were negatively correlated with HAM-D scores (r = -0.49, p = 0.007). After 8 weeks of treatment, sBDNF levels of patients had increased significantly (mean, 33.3 ng/ml; [S.D., 9.9]; p < 0.001) and no longer differed from those of controls. These results support the hypothesis that BDNF might play a critical role in the pathophysiology of major depressive disorder and successful antidepressant treatment increases the attenuated BDNF levels in depressed patients.
Deficits in cognitive flexibility may be a candidate for being a trait marker of psychotic features among bipolar patients. However, verbal fluency, psychomotor speed and sustained attention deficits may be candidates for vulnerability indicators of bipolar disorder in general.
BACKGROUND: Schizophrenia and bipolar disorder share genetic liability, and some structural brain abnormalities are common to both conditions. First-degree relatives of patients with schizophrenia (FDRs-SZ) show similar brain abnormalities to patients, albeit with smaller effect sizes. Imaging findings in first-degree relatives of patients with bipolar disorder (FDRs-BD) have been inconsistent in the past, but recent studies report regionally greater volumes compared with control subjects. METHODS: We performed a meta-analysis of global and subcortical brain measures of 6008 individuals (1228 FDRs-SZ, 852 FDRs-BD, 2246 control subjects, 1016 patients with schizophrenia, 666 patients with bipolar disorder) from 34 schizophrenia and/or bipolar disorder family cohorts with standardized methods. Analyses were repeated with a correction for intracranial volume (ICV) and for the presence of any psychopathology in the relatives and control subjects. RESULTS: FDRs-BD had significantly larger ICV (d = 10.16, q , .05 corrected), whereas FDRs-SZ showed smaller thalamic volumes than control subjects (d = 20.12, q , .05 corrected). ICV explained the enlargements in the brain measures in FDRs-BD. In FDRs-SZ, after correction for ICV, total brain, cortical gray matter, cerebral white matter, cerebellar gray and white matter, and thalamus volumes were significantly smaller; the cortex was thinner (d , 20.09, q , .05 corrected); and third ventricle was larger (d = 10.15, q , .05 corrected). The findings were not explained by psychopathology in the relatives or control subjects. CONCLUSIONS: Despite shared genetic liability, FDRs-SZ and FDRs-BD show a differential pattern of structural brain abnormalities, specifically a divergent effect in ICV. This may imply that the neurodevelopmental trajectories leading to brain anomalies in schizophrenia or bipolar disorder are distinct.
Aims: Schizophrenia is a psychiatric disorder manifesting with heterogeneous symptom clusters and clinical presentations. The deficit syndrome is the condition defined by the existence of primarily negative symptoms, and patients with the deficit syndrome differ from non‐deficit patients on measures of brain structure and function. In the current study, by using diffusion tensor imaging (DTI), we investigated the frontotemporal connectivity that is hypothesized to differ between deficit and non‐deficit schizophrenia.
Methods: Twenty‐nine patients and 17 healthy controls were included in the study. The patients had deficit (n = 11) or non‐deficit (n = 18) schizophrenia and they were evaluated clinically with the Schedule for Deficit Syndrome (SDS) and Positive and Negative Syndrome Scale (PANSS). Diffusion‐based images were obtained with a 1.5T Siemens Magnetic Resonance Imaging machine and analyses were carried out with Functional Magnetic Resonance Imaging of the Brain Library Software – Diffusion tool box software.
Results: The fractional anisotropy values in the left uncinate fasciculus of schizophrenia patients with the deficit syndrome were lower than those of non‐deficit patients and the controls. There were no differences between non‐deficit schizophrenia patients and controls.
Conclusion: These findings provide evidence of left uncinate fasciculus damage resulting in disrupted communication between orbitofrontal prefrontal areas and temporal areas in deficit schizophrenia patients.
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