Functional network connectivity in early-stage schizophrenia.

Schizophrenia is a disorder of altered neural connections resulting in impaired information integration. Whole brain assessment of within- and between-network connections may determine how information processing is disrupted in schizophrenia. Patients with early-stage schizophrenia (n = 56) and a matched control sample (n = 32) underwent resting-state fMRI scans. Gray matter regions were organized into nine distinct functional networks. Functional connectivity was calculated between 278 gray matter regions for each subject. Network connectivity properties were defined by the mean and variance of correlations of all regions. Whole-brain network measures of global efficiency (reflecting overall interconnectedness) and locations of hubs (key regions for communication) were also determined. The control sample had greater connectivity between the following network pairs: somatomotor-limbic, somatomotor-default mode, dorsal attention-default mode, ventral attention-limbic, and ventral attention-default mode. The patient sample had greater variance in interactions between ventral attention network and other functional networks. Illness duration was associated with overall increases in the variability of network connections. The control group had higher global efficiency and more hubs in the cerebellum network, while patient group hubs were more common in visual, frontoparietal, or subcortical networks. Thus, reduced functional connectivity in patients was largely present between distinct networks, rather than within-networks. The implications of these findings for the pathophysiology of schizophrenia are discussed.

Relationship of auditory electrophysiological responses to magnetic resonance spectroscopy metabolites in Early Phase Psychosis.

Both auditory evoked responses and metabolites measured by magnetic resonance spectroscopy (MRS) are altered in schizophrenia and other psychotic disorders, but the relationship between electrophysiological and metabolic changes are not well characterized. We examined the relation of MRS metabolites to cognitive and electrophysiological measures in individuals during the early phase of psychosis (EPP) and in healthy control subjects. The mismatch negativity (MMN) of the auditory event-related potential to duration deviant tones and the auditory steady response (ASSR) to 40 Hz stimulation were assessed. MRS was used to quantify glutamate+glutamine (Glx), N-Acetylasparate (NAA), creatine (Cre), myo-inositol (Ins) and choline (Cho) at a voxel placed medially in the frontal cortex. MMN amplitude and ASSR power did not differ between groups. The MRS metabolites Glx, Cre and Cho were elevated in the psychosis group. Partial least squares analysis in the patient group indicated that elevated levels of MRS metabolites were associated with reduced MMN amplitude and increased 40 Hz ASSR power. There were no correlations between the neurobiological measures and clinical measures. These data suggest that elevated neurometabolites early in psychosis are accompanied by altered auditory neurotransmission, possibly indicative of a neuroinflammatory or excitotoxic disturbance which disrupts a wide range of metabolic processes in the cortex.

Effects of 12-month, double-blind N-acetyl cysteine on symptoms, cognition and brain morphology in early phase schizophrenia spectrum disorders.

BACKGROUND: Currently approved medications for schizophrenia are relatively ineffective for negative symptoms and cognitive impairment. N-Acetyl Cysteine (NAC) is a neuroprotective agent that improved general symptoms, cognitive impairment and negative symptoms in some but not all studies, but failed to improve positive symptoms in patients with schizophrenia. Progressive brain mass loss (PBML) has been consistently observed in early phase schizophrenia. NAC mitigates the deleterious effects oxidative stress, inflammation and glutamatergic excitotoxicity and these three pathological processes are hypothesized to contribute to PBML. METHODS: In this study, we assessed the effects NAC (3600mg/day) in a 52-week, double-blind, placebo controlled trial on symptoms, and cognition in early phase schizophrenia spectrum disorders (N=60). In the context of the clinical trial, we explored the effects of NAC on brain morphology. RESULTS: NAC significantly improved (time×group) PANSS total (F=14.7, p<0.001), negative (F=5.1, p=0.024) and disorganized thought (F=13.7, p<0.001) symptom scores. NAC failed to improve PANSS positive symptoms and BACS cognitive scores. In preliminary analyses, baseline right (r=-0.48, p=0.041) and left (r=-0.45, p=0.018) total cortical thickness, and thickness in other cortical regions, were associated with NAC related improvement in PANSS total scores, but NAC, as compared to placebo, did not significantly impact brain morphology over the study treatment period. CONCLUSIONS: These results replicate some but not all previous findings of NAC efficacy. Preliminary results suggest that NAC's symptom effects may be related to structural integrity, but NAC failed to demonstrate treatment effects on longitudinal measures of brain morphology. ClinicalTrials.gov Identifier: NCT01339858.

Characterization of white matter abnormalities in early-stage schizophrenia.

AIM: White matter abnormalities have been reported in schizophrenia and may indicate altered cortical network integrity and structural connectivity, which have been hypothesized as key pathophysiological components of this illness. In this study, we aimed to further characterize the nature and progression of white matter alterations during the early stages of the disorder. METHODS: We employed diffusion tensor imaging (DTI) approaches to investigate fractional anisotropy (FA), radial diffusivity (RD) and axial diffusivity (AD) in 40 patients with schizophrenia and related psychotic disorders (aged 18-30 years) who were within 5 years of illness, along with an age-, sex- and race-matched sample of 21 healthy controls. Relationships with illness duration, lifetime antipsychotic medication exposure and symptom levels were examined. RESULTS: Patients had lower FA and higher RD than controls in numerous white matter tracts, including the corpus callosum (CC) and the superior longitudinal fasciculus. Illness duration was associated with lower FA and higher RD, most prominently in the CC. No group differences or relationships to illness duration were detected with AD, and no relationships between any DTI measurements and lifetime antipsychotic medication use were found. CONCLUSIONS: This investigation provides evidence of widespread disruptions to structural connectivity in the early stages of schizophrenia. The relationship to illness duration, coupled with an absence of relationships to AD or antipsychotic drug exposure, provides evidence of a progressive disease process, although prospective assessments with repeated DTI measurements are needed to fully characterize the trajectory of white matter abnormalities in this illness.

Association of medial prefrontal resting state functional connectivity and metacognitive capacity in early phase psychosis.

Metacognition refers to a range of cognitive processes that allow one to form complex ideas of self and others and to use this information to navigate psychosocial challenges. Several studies in both early-phase and prolonged schizophrenia have demonstrated not only that significant deficits in metacognitive ability are present, but importantly that they are associated with significant functional impairment and decreased quality of life. In spite of the importance of metacognitive impairment in schizophrenia, relatively little is known about the biological substrates that may contribute to this dysfunction. In this study, we examined the relationship between resting state functional connectivity of the medial prefrontal cortex (mPFC), a structure shown in prior voxel-based morphometry studies to be associated with metacognition, with metacognitive function in an early-phase psychosis cohort (n=18). Analyses revealed a positive association of resting state functional connectivity between the mPFC and precuneus and posterior cingulate structures and metacognitive ability. These results provide evidence of disrupted resting state connectivity in structures relevant to metacognitive dysfunction in early-phase psychosis, which may have implications for pathophysiological models of complex cognitive deficits in this illness.

Utilization and Cost of Health Care Services During the First Episode of Psychosis.

OBJECTIVE: Because of the chronicity, severity, and marked psychosocial impairment that may characterize the illness, schizophrenia is an incredibly costly disease. Recent data indicate that intervention earlier in the course of schizophrenia produces cost savings. This study compared health service utilization and associated costs for patients receiving treatment for first-episode psychosis (FEP) delivered within the early-intervention (EI) model at the Prevention and Recovery Center for Early Psychosis (PARC) and for a matched sample of FEP patients receiving treatment as usual at a geographically similar mental health clinic. METHODS: This study was a retrospective assessment of 76 PARC patients and 75 patients receiving treatment as usual who were matched by age, race, sex, and diagnosis. Clinical and health service utilization data were extracted from the Midtown and Regenstrief Medical Record Systems, and differences between demographic variables, health service utilization, and cost of services were compared. RESULTS: Although individuals at PARC had higher physician and nurse visit costs, these were offset by a decrease in costs for acute service utilization. The PARC cohort did not show any difference from the comparison group in terms of total outpatient clinic services used and had fewer inpatient, psychiatric crisis, and emergency room services. Cost analyses reflected a total estimated savings of just over $6,900 per patient. CONCLUSIONS: These findings indicate not only that EI results in cost savings but that increasing medical services may be key in reducing the use of acute services, presumably because of a reduction in psychiatric and general medical pathology.

Affective systems induce formal thought disorder in early-stage psychosis.

Although formal thought disorder (FTD) has been described since early conceptualizations of psychosis, its underlying mechanisms are unclear. Evidence suggests FTD may be influenced by affective and cognitive systems; however, few have examined these relationships-with none focusing on early-stage psychosis (EP). In this study, positive FTD and speech production were measured in sex- and race-matched EP (n = 19) and healthy control (n = 19) groups by assessing "reactivity"-a change in experimental compared with baseline conditions-across baseline, affective, and cognitive conditions. Relationships with functioning were also examined within each group. Three key findings emerged: (a) the EP group displayed large differences in positive FTD and speech production, (b) those with EP exhibited affective reactivity for positive FTD, and (c) positive FTD and affective reactivity were linked with poor real-world functioning in EP and these relationships did not considerably change when controlling for positive symptom (e.g., delusions, hallucinations) severity. Our findings provide preliminary evidence that affective, but not cognitive, systems play a critical role in positive FTD. Affective reactivity, in particular, may aid in predicting those with EP who go on to develop serious social impairments. Future work should focus on whether affective systems differentially influence those at separate points on the psychosis-spectrum in an effort to establish evidence-based treatments for FTD. (PsycINFO Database Record

Functional neuroanatomical correlates of episodic memory impairment in early phase psychosis.

Studies have demonstrated that episodic memory (EM) is often preferentially disrupted in schizophrenia. The neural substrates that mediate EM impairment in this illness are not fully understood. Several functional magnetic resonance imaging (fMRI) studies have employed EM probe tasks to elucidate the neural underpinnings of impairment, though results have been inconsistent. The majority of EM imaging studies have been conducted in chronic forms of schizophrenia with relatively few studies in early phase patients. Early phase schizophrenia studies are important because they may provide information regarding when EM deficits occur and address potential confounds more frequently observed in chronic populations. In this study, we assessed brain activation during the performance of visual scene encoding and recognition fMRI tasks in patients with earlyphase psychosis (n = 35) and age, sex, and race matched healthy control subjects (n = 20). Patients demonstrated significantly lower activation than controls in the right hippocampus and left fusiform gyrus during scene encoding and lower activation in the posterior cingulate, precuneus, and left middle temporal cortex during recognition of target scenes. Symptom levels were not related to the imaging findings, though better cognitive performance in patients was associated with greater right hippocampal activation during encoding. These results provide evidence of altered function in neuroanatomical circuitry subserving EM early in the course of psychotic illness, which may have implications for pathophysiological models of this illness.

Smoking on school property as a risk factor for substance use among adolescent smokers.

The purpose of the current study was to determine if smoking on high-school property was associated with increased risk for other substance use among U.S. adolescents. Secondary analyses were carried out with data from the 2011 Youth Risk Behavior Survey (YRBS, N = 15,503). Only adolescents who reported smoking at least one cigarette in the last 30 days were selected for analyses (n = 2531, 44% female). Alcohol, marijuana, and cocaine use was assessed among participants. Binary logistic regression analysis was carried out to examine the relationship between smoking on school property (yes versus no) with each of the substance use variables. Adolescent smokers who reported smoking on school property were significantly more likely to report substance use across all substances examined compared to smokers who did not smoke on campus. For example, campus smokers were 3.91 times more likely to use marijuana in their lifetime and 3.85 times more likely to have used crack or cocaine in their lifetime compared to smokers who did not smoke on campus. Health care providers who provide services to adolescents should screen for smoking on school property to help identify adolescents at increased risk for substance use.