Prog Neuropsychopharmacol Biol Psychiatry
April 2020
Widespread structrual abnormalities in subcortical brain regions have been identified in patients with schizophrenia. However, only a few studies have examined the neuroanatomical profiles of patients with treatment-resistant schizophrenia. The aim of this study was to compare differences in subcortical and hippocampal volumes between: (i) treatment-resistant patients who are non-responders to both first-line antipsychotics and clozapine (URS), (ii) treatment-resistant patients who are non-responders to first-line antipsychotics but are responders to clozapine (CLZ-Resp), (iii) responders to first-line antipsychotics (FL-Resp), and (iv) healthy controls.
View Article and Find Full Text PDFBackground: Impaired illness awareness or insight into illness (IIA) is a common feature of schizophrenia that contributes to medication nonadherence and poor clinical outcomes. Neuroimaging studies suggest IIA may arise from interhemispheric imbalance in frontoparietal regions, particularly in the posterior parietal area (PPA) and the dorsolateral prefrontal cortex (dlPFC). In this pilot study, we examined the effects of transcranial direct current stimulation (tDCS) on brain regions implicated in IIA.
View Article and Find Full Text PDFTranscranial direct current stimulation (tDCS) has generated interest in recent years as a potential adjunctive treatment for patients with schizophrenia. The primary objective of this meta-analysis was to evaluate the efficacy of tDCS on positive symptoms, particularly auditory hallucinations, and negative symptoms. A literature search of randomized sham-controlled trials was conducted using the OVID database on October 9, 2018.
View Article and Find Full Text PDFNeuropsychopharmacology
September 2019
Electroconvulsive therapy (ECT) is the most effective treatment for severe depression, although the underlying mechanisms remain unclear. Animal studies have consistently shown that electroconvulsive stimulation induces neuroplastic changes in the dentate gyrus. To date, few studies have investigated the effect of ECT on human hippocampal subfields.
View Article and Find Full Text PDFAims: Impaired illness awareness or not accepting that one has obesity is an understudied phenomenon that may negatively influence treatment adherence and clinical outcomes. The purpose of this study was to perform a systematic review of available measures of obesity awareness, and subsequently develop and validate a novel scale that measures the core domains of obesity awareness.
Methods: A systematic review of the literature revealed no illness specific measure of subjective obesity awareness.
Background: The relationship between dopamine D receptor (DR) occupancy and impaired illness awareness (IIA) remains unclear. While IIA is associated with illness severity and cognitive dysfunction, antipsychotic medication, the principal treatment for schizophrenia, indirectly improves IIA, but may simultaneously contribute to cognitive dysfunction at supratherapeutic doses.
Aim And Methods: We investigated the influence of estimated DR (Est.
Aims: Impaired illness awareness or not accepting that one has obesity is an understudied phenomenon that may negatively influence treatment adherence and clinical outcomes. The purpose of this study was to perform a systematic review of available measures of obesity awareness, and subsequently develop and validate a novel scale that measures the core domains of obesity awareness.
Methods: A systematic review of the literature revealed no illness specific measure of subjective obesity awareness.
Background: Cognitive reserve is the acquired capacity reflecting a functional brain adaptability/flexibility in the context of aging. Educational attainment is thought to be among the most important factors that contribute to cognitive reserve.
Objective: The aim of this study is to investigate the relationships among duration of education and Alzheimer's disease (AD) related neuroimaging biomarkers such as amyloid-β deposition, glucose metabolism, and brain volumes in each stage of AD.
Prog Neuropsychopharmacol Biol Psychiatry
August 2018
Background: Studies using proton magnetic resonance spectroscopy (H-MRS) have reported altered neurometabolite levels in patients with schizophrenia. However, results are possibly confounded by the influence of antipsychotic (AP). Thus, this meta-analysis aimed to examine neurometabolite levels in AP-naïve/free patients with schizophrenia.
View Article and Find Full Text PDFImpaired illness awareness or not accepting that one has hypertension (HTN) may be an important predictor of treatment adherence and optimal blood pressure control. The purpose of this study was to perform a systematic review of available instruments to evaluate HTN awareness, and subsequently present a novel scale that measures the core domains of subjective illness awareness in HTN. Based on the absence of any validated HTN specific measure identified through our review, the Blood Pressure Awareness and Insight Scale (BASIS) was developed (www.
View Article and Find Full Text PDFBackground: Electroconvulsive therapy (ECT) is one of the most effective treatments for depression, although the underlying mechanisms remain unclear. Animal studies have shown that electroconvulsive shock induced neuroplastic changes in the hippocampus. Aims To summarise volumetric magnetic resonance imaging studies investigating the effects of ECT on limbic brain structures.
View Article and Find Full Text PDFPrevious proton magnetic resonance spectroscopy (H-MRS) studies have reported disrupted levels of various neurometabolites in patients with schizophrenia. An area of particular interest within this patient population is the striatum, which is highly implicated in the pathophysiology of schizophrenia. The present study examined neurometabolite levels in the striatum of 12 patients with schizophrenia receiving antipsychotic treatment for at least 1 year and 11 healthy controls using 3-Tesla H-MRS (PRESS, TE = 35 ms).
View Article and Find Full Text PDFLevels of striatal dopamine (DA) may be positively correlated with levels of striatal glutamate (Glu). While reduced insulin sensitivity (%S) has been associated with reduced striatal DA levels in healthy non-obese persons, whether reduced %S is also associated with reduced striatal Glu levels has not yet been established. Using H-MRS, we measured levels of several neurometabolites in the striatum and dorsolateral prefrontal cortex (DLPFC) of seventeen healthy non-obese persons (9 female, mean age: 28.
View Article and Find Full Text PDFObjective: Motivational deficits are prevalent in patients with schizophrenia, persist despite antipsychotic treatment, and predict long-term outcomes. Evidence suggests that patients with greater amotivation have smaller ventral striatum (VS) volumes. We wished to replicate this finding in a sample of older, chronically medicated patients with schizophrenia.
View Article and Find Full Text PDFObjective: Anosognosia, or impaired illness awareness, is a common feature of Alzheimer's disease (AD) and less so of mild cognitive impairment (MCI). Importantly, anosognosia negatively influences clinical outcomes for patients and their caregivers and may predict the conversion from MCI to AD. This study aimed to examine (1) the relationship between brain glucose metabolism as measured by fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) and anosognosia in patients with MCI and AD and (2) the predictive utility of anosognosia in patients with MCI for later conversion to AD, even when controlling for other factors, including gender, education, apolipoprotein E ε4 carrier status, dementia severity, and cognitive dysfunction.
View Article and Find Full Text PDFThis study was aimed to explore self-report auditory verbal hallucinations to provide unique and valuable information in addition to clinician-rated assessment in patients with schizophrenia. The VAGUS (http://www.vagusonline.
View Article and Find Full Text PDFImpulsivity is considered a vulnerability trait for addiction. Recently, we found trait non-planning impulsiveness measured with the Karolinska Scales of Personality was negatively correlated with dopamine D receptor availability in the ventral striatum of healthy humans. While also observed in rodents, human studies have failed to find this association with other measures of trait impulsivity.
View Article and Find Full Text PDFThe clinical and structural trajectories of suspected non-Alzheimer' pathology (SNAP) remain elusive due to its heterogeneous etiology. Baseline and longitudinal clinical (global cognition, daily functioning, symptoms of dementia, and learning memory) and hippocampal volume trajectories over two years were compared between patients with amnestic mild cognitive impairment (aMCI) with SNAP with reduced hippocampal volumes (SNAP+HIPPO) and aMCI patients with SNAP without reduced hippocampal volumes. SNAP+HIPPO showed overall worse baseline cognitive functions.
View Article and Find Full Text PDFBackground: Abnormalities in dopamine (DA) and brain morphology are observed in several neuropsychiatric disorders. However, it is not fully understood how these abnormalities may relate to one another. For such in vivo findings to be used as biomarkers for neuropsychiatric disease, it must be understood how variability in DA relates to brain structure under healthy conditions.
View Article and Find Full Text PDFSuspected non-Alzheimer's disease pathology (SNAP) characterizes individuals showing neurodegeneration (e.g., hypometabolism) without amyloid-β (Aβ).
View Article and Find Full Text PDFBackground: Patients with schizophrenia (SCZ) tend to sample less information when making a decision, jumping to conclusions (JTC) without sufficient evidence. This "JTC bias" may be a trait marker of the disease and may not improve with antipsychotic treatment. We conducted a double-blind, placebo-controlled trial to test whether intranasal oxytocin could reduce JTC in stable, medicated patients with SCZ and healthy controls (HCs).
View Article and Find Full Text PDFKynurenic acid (KYNA) is an endogenous antagonist of N-methyl-D-aspartate and α7 nicotinic acetylcholine receptors that is derived from astrocytes as part of the kynurenine pathway of tryptophan degradation. Evidence suggests that abnormal KYNA levels are involved in the pathophysiology of schizophrenia. However, this has never been assessed through a meta-analysis.
View Article and Find Full Text PDFObjective: Although hyperprolactinemia carries a long-term risk of morbidity, the threshold of dopamine D2/3 receptor (D2/3R) occupancy for hyperprolactinemia has not been investigated in older patients with schizophrenia. Data were taken from a positron emission tomography (PET) study conducted between August 2007 and August 2015. The present post hoc study included 42 clinically stable outpatients with schizophrenia (DSM-IV) (mean ± SD age = 60.
View Article and Find Full Text PDFObjective: It is inconclusive as to whether benzodiazepines (BZDs) are related to cognitive deterioration in the elderly populations. Animal studies suggest that γ-aminobutyric acid A receptor agonists, such as BZDs, may prevent Aβ-neurotoxicity and reduce β-amyloid (Aβ). However, no studies have investigated the effects of BZD use on Aβ in humans.
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