Treatment implications of the schizophrenia prodrome

Therapeutic antischizophrenic activity of prodigiosin and selenium co-supplementation against amphetamine hydrochloride-induced behavioural changes and oxidative, inflammatory, and apoptotic challenges in rats

Schizophrenia (SCZ), a multifactorial neuropsychiatric disorder, is treated with inefficient antipsychotics and linked to poor treatment outcomes. This study, therefore, investigated the combined administration of prodigiosin (PDG) and selenium (Na₂SeO₃) against SCZ induced by amphetamine (AMPH) in rats. Animals were allocated into four groups corresponding to their respective 7-day treatments: control, AMPH (2 mg/kg), PDG (300 mg/kg) + Na₂SeO₃ (2 mg/kg), and AMPH + PDG + Na₂SeO₃. The model group exhibited biochemical, molecular, and histopathological changes similar to those of the SCZ group. Contrastingly, co-administration of PDG and Na₂SeO₃ significantly increased the time for social interaction and decreased AChE and dopamine. It also downregulated the gene expression of NMDAR1 and restored neurotrophin (BDNF and NGF) levels. Further, PDG combined with Na₂SeO₃ improved the antioxidant defence of the hippocampus by boosting the activities of SOD, CAT, GPx, and GR. These findings were accompanied by an increased GSH, alongside decreased MDA and NO levels. Furthermore, schizophrenic rats having received PDG and Na₂SeO₃ displayed markedly lower IL-1β and TNF-α levels compared to the model group. Interestingly, remarkable declines in the Bax (pro-apoptotic) and increases in Bcl-2 (anti-apoptotic) levels were observed in the SCZ group that received PDG and Na₂SeO₃. The hippocampal histological examination confirmed these changes. Collectively, these findings show that the co-administration of PDG and Na₂SeO₃ may have a promising therapeutic effect for SCZ. This is mediated by mechanisms related to the modulation of cholinergic, dopaminergic, and glutaric neurotransmission and neurotrophic factors, alongside the suppression of oxidative damage, neuroinflammation, and apoptosis machinery.

Cost-Effectiveness of Early Intervention in Psychosis: A Modeling Study

OBJECTIVE

Programs for early intervention in psychosis have shown clinical efficacy. The authors aimed to evaluate the cost-effectiveness of early intervention programs compared with standard care for the treatment of first-episode psychosis in the United States.

METHODS

A decision-analytic model integrating published data on clinical efficacy, costs, and health utilities was developed to evaluate early intervention versus standard care over the lifetime of patients after their first psychotic episode. Model input data were derived from meta-analyses, clinical trials, and U.S. national data. The main outcomes included hospitalizations, employment rate, quality-adjusted life years (QALYs), lifetime health care costs, and incremental cost-effectiveness ratios (ICERs).

RESULTS

Compared with patients receiving standard care, patients in the early intervention strategy had 3.2 fewer hospitalizations and 2.7 more years of employment over the course of their remaining life expectancy. From a health care perspective, early intervention had an ICER of approximately $51,600 per QALY. From a societal perspective, early intervention saved costs (i.e., yielded greater health benefits and had lower costs compared with standard care). Results were sensitive to the effect of early intervention on suicide, cost of standard care, cost of early intervention, and the effect (relative risk) of early intervention on employment. A scenario analysis that excluded the effect (i.e., hazard ratio) of early intervention on suicide yielded an ICER of approximately $197,000 per QALY.

CONCLUSIONS

These results suggest that it is economically beneficial to fund early intervention in psychosis programs in the United States. The findings indicate that early intervention in psychosis saves costs (from the societal perspective) and is cost-effective (health care sector perspective).

Cannabidiol for at risk for psychosis youth: A randomized controlled trial

BACKGROUND

No biological treatment has been firmly established for the at-risk stage of psychotic disorder. In this study we aim to test if subthreshold psychotic symptoms can be effectively treated with cannabidiol (CBD), a non-psychoactive compound of the plant Cannabis sativa. The question has taken on increased importance in the wake of evidence questioning both the need and efficacy of specific pharmacological interventions in the ultra-high risk (UHR) for psychosis group.

METHODS

Three-arm randomized controlled trial of 405 patients (135 per arm) aged 12-25 years who meet UHR for psychosis criteria. The study includes a 6-week lead-in phase during which 10% of UHR individuals are expected to experience symptom remission. Participants will receive CBD (per oral) at doses 600 or 1000 mg per day (fixed schedule) for 12 weeks. Participants in the third arm of the trial will receive matching placebo capsules. Primary outcome is severity of positive psychotic symptoms as measured by the Comprehensive Assessment of At-Risk Mental States at 12 weeks. We hypothesize that CBD will be significantly more effective than placebo in improving positive psychotic symptoms in UHR patients. All participants will also be followed up 6 months post baseline to evaluate if treatment effects are sustained.

CONCLUSION

This paper reports on the rationale and protocol of the Cannabidiol for At Risk for psychosis Youth (CanARY) study. This study will test CBD for the first time in the UHR phase of psychotic disorder.

Polygenic risk scores across the extended psychosis spectrum

As early detection of symptoms in the subclinical to clinical psychosis spectrum may improve health outcomes, knowing the probabilistic susceptibility of developing a disorder could guide mitigation measures and clinical intervention. In this context, polygenic risk scores (PRSs) quantifying the additive effects of multiple common genetic variants hold the potential to predict complex diseases and index severity gradients. PRSs for schizophrenia (SZ) and bipolar disorder (BD) were computed using Bayesian regression and continuous shrinkage priors based on the latest SZ and BD genome-wide association studies (Psychiatric Genomics Consortium, third release). Eight well-phenotyped groups (n = 1580; 56% males) were assessed: control (n = 305), lower (n = 117) and higher (n = 113) schizotypy (both groups of healthy individuals), at-risk for psychosis (n = 120), BD type-I (n = 359), BD type-II (n = 96), schizoaffective disorder (n = 86), and SZ groups (n = 384). PRS differences were investigated for binary traits and the quantitative Positive and Negative Syndrome Scale. Both BD-PRS and SZ-PRS significantly differentiated controls from at-risk and clinical groups (Nagelkerke's pseudo-R2: 1.3-7.7%), except for BD type-II for SZ-PRS. Out of 28 pairwise comparisons for SZ-PRS and BD-PRS, 9 and 12, respectively, reached the Bonferroni-corrected significance. BD-PRS differed between control and at-risk groups, but not between at-risk and BD type-I groups. There was no difference between controls and schizotypy. SZ-PRSs, but not BD-PRSs, were positively associated with transdiagnostic symptomology. Overall, PRSs support the continuum model across the psychosis spectrum at the genomic level with possible irregularities for schizotypy. The at-risk state demands heightened clinical attention and research addressing symptom course specifiers. Continued efforts are needed to refine the diagnostic and prognostic accuracy of PRSs in mental healthcare.

Oxidative Stress in the Early Stage of Psychosis

BACKGROUND

In the past few decades, increasing evidence in the literature has appeared describing the role of the antioxidant defense system and redox signaling in the multifactorial pathophysiology of psychosis. It is of interest to clinicians and researchers alike that abnormalities of the antioxidant defense system are associated with alterations of cellular membranes, immune functions and neurotransmission, all of which have some clinical implications.

METHODS

This narrative review summarizes the evidence regarding oxidative stress in the early stages of psychosis. We included 136 peer-reviewed articles published from 2007 to 2020 on PubMed EMBASE, The Cochrane Library and Google Scholar.

RESULTS

Patients affected by psychotic disorders show a decreased level of non-enzymatic antioxidants, an increased level of lipid peroxides, nitric oxides, and a homeostatic imbalance of purine catabolism. In particular, a significantly reduced antioxidant defense has been described in the early onset first episode of psychosis, including reduced levels of glutathione. Also, it has been shown that a decreased basal low -antioxidant capacity correlates with cognitive deficits and negative symptoms, mostly related to glutamate-receptor hypofunction. In addition, atypical antipsychotic drugs seem to show significant antioxidant activity. These factors are critical in order to treat cases of first-onset psychosis effectively.

CONCLUSION

This systematic review indicates the importance that must be given to anti-oxidant defense systems.

Antioxidant Potential of Psychotropic Drugs: From Clinical Evidence to In Vitro and In Vivo Assessment and toward a New Challenge for in Silico Molecular Design

Due to high oxygen consumption, the brain is particularly vulnerable to oxidative stress, which is considered an important element in the etiopathogenesis of several mental disorders, including schizophrenia, depression and dependencies. Despite the fact that it is not established yet whether oxidative stress is a cause or a consequence of clinic manifestations, the intake of antioxidant supplements in combination with the psychotropic therapy constitutes a valuable solution in patients' treatment. Anyway, some drugs possess antioxidant capacity themselves and this aspect is discussed in this review, focusing on antipsychotics and antidepressants. In the context of a collection of clinical observations, in vitro and in vivo results are critically reported, often highlighting controversial aspects. Finally, a new challenge is discussed, i.e., the possibility of assessing in silico the antioxidant potential of these drugs, exploiting computational chemistry methodologies and machine learning. Despite the physiological environment being incredibly complex and the detection of meaningful oxidative stress biomarkers being all but an easy task, a rigorous and systematic analysis of the structural and reactivity properties of antioxidant drugs seems to be a promising route to better interpret therapeutic outcomes and provide elements for the rational design of novel drugs.

Potential therapeutic antipsychotic effects of Naringin against ketamine-induced deficits in rats: Involvement of Akt/GSK-3β and Wnt/β-catenin signaling pathways

AIM

Schizophrenia is a chronic, disabling and one of the major neurological illnesses affecting nearly 1% of the global population. Currently available antipsychotic medications possess limited effects. The current research aimed at investigating potential therapeutic add-on benefit to enhance the effects of clozapine anti-schizophrenic.

MAIN METHODS

To induce schizophrenia, ketamine was administered at a dose of 25 mg/kg i.p. for 14 consecutive days. Naringin was administered to Wistar rats at a dose of 100 mg/kg orally, alone or in combination with clozapine 5 mg/kg i.p from day 8 to day 14. Furthermore, behavioral tests were conducted to evaluate positive, negative and cognitive symptoms of schizophrenia. In addition, neurotransmitters' levels were detected using HPLC. Moreover, oxidative stress markers were assessed using spectrophotometry. Furthermore, apoptotic and wnt/β-catenin pathway markers were determined using western blotting (Akt, GSK-3β and β-catenin), colorimetric methods (Caspase-3) and immunohistochemistry (Bax, Bcl2 and cytochrome c).

KEY FINDINGS

Ketamine induced positive, negative and cognitive schizophrenia symptoms together with neurotransmitters' imbalance. In addition, ketamine treatment caused significant glutathione depletion, lipid peroxidation and reduction in catalase activity. Naringin and/or clozapine treatment significantly attenuated ketamine-induced schizophrenic symptoms and oxidative injury. Additionally, ketamine provoked apoptosis via increasing Bax/Bcl2 expression, caspase-3 activity, and Cytochrome C and Akt protein expression while naringin/clozapine treatment significantly inhibited this apoptotic effect. Moreover, naringin activated the neurodevelopmental wnt/β-catenin signaling pathway evidenced by increasing pGSK-3β and reducing pβ-catenin protein expression.

SIGNIFICANCE

These findings may suggest that naringin possesses a potential therapeutic add-on effect against ketamine-induced schizophrenia.

Treatment-Resistant to Antipsychotics: A Resistance to Everything? Psychotherapy in Treatment-Resistant Schizophrenia and Nonaffective Psychosis: A 25-Year Systematic Review and Exploratory Meta-Analysis

Background: Roughly 30% of schizophrenia patients fail to respond to at least two antipsychotic trials. Psychosis has been traditionally considered to be poorly sensitive to psychotherapy. Nevertheless, there is increasing evidence that psychological interventions could be considered in treatment-resistant psychosis (TRP). Despite the relevance of the issue and the emerging neurobiological underpinnings, no systematic reviews have been published. Here, we show a systematic review of psychotherapy interventions in TRP patients of the last 25 years. Methods: The MEDLINE/PubMed, ISI WEB of Knowledge, and Scopus databases were inquired from January 1, 1993, to August 1, 2018, for reports documenting augmentation or substitution with psychotherapy for treatment-resistant schizophrenia (TRS) and TRP patients. Quantitative data fetched by Randomized Controlled Trials (RCTs) were pooled for explorative meta-analysis. Results: Forty-two articles have been found. Cognitive behavioral therapy (CBT) was the most frequently recommended psychotherapy intervention for TRS (studies, n = 32, 76.2%), showing efficacy for general psychopathology and positive symptoms as documented by most of the studies, but with uncertain efficacy on negative symptoms. Other interventions showed similar results. The usefulness of group therapy was supported by the obtained evidence. Few studies focused on negative symptoms. Promising results were also reported for resistant early psychosis. Limitations: Measurement and publication bias due to the intrinsic limitations of the appraised original studies. Conclusions: CBT, psychosocial intervention, supportive counseling, psychodynamic psychotherapy, and other psychological interventions can be recommended for clinical practice. More studies are needed, especially for non-CBT interventions and for all psychotherapies on negative symptoms.

Potential use of clinical polygenic risk scores in psychiatry - ethical implications and communicating high polygenic risk

Psychiatric disorders present distinct clinical challenges which are partly attributable to their multifactorial aetiology and the absence of laboratory tests that can be used to confirm diagnosis or predict risk. Psychiatric disorders are highly heritable, but also polygenic, with genetic risk conferred by interactions between thousands of variants of small effect that can be summarized in a polygenic risk score. We discuss four areas in which the use of polygenic risk scores in psychiatric research and clinical contexts could have ethical implications. First, there is concern that clinical use of polygenic risk scores may exacerbate existing health inequities. Second, research findings regarding polygenic risk could be misinterpreted in stigmatising or discriminatory ways. Third, there are concerns associated with testing minors as well as eugenics concerns elicited by prenatal polygenic risk testing. Fourth, potential challenges that could arise with the feedback and interpretation of high polygenic risk for a psychiatric disorder would require consideration. While there would be extensive overlap with the challenges of feeding back genetic findings in general, the potential clinical use of polygenic risk scoring warrants discussion in its own right, given the recency of this possibility. To this end, we discuss how lay interpretations of risk and genetic information could intersect. Consideration of these factors would be necessary for ensuring effective and constructive communication and interpretation of polygenic risk information which, in turn, could have implications for the uptake of any therapeutic recommendations. Recent advances in polygenic risk scoring have major implications for its clinical potential, however, care should be taken to ensure that communication of polygenic risk does not feed into problematic assumptions regarding mental disorders or support reductive interpretations.

Staged Treatment in Early Psychosis: A sequential multiple assignment randomised trial of interventions for ultra high risk of psychosis patients

AIM

Previous research indicates that preventive intervention is likely to benefit patients "at risk" of psychosis, in terms of functional improvement, symptom reduction and delay or prevention of onset of threshold psychotic disorder. The primary aim of the current study is to test outcomes of ultra high risk (UHR) patients, primarily functional outcome, in response to a sequential intervention strategy consisting of support and problem solving (SPS), cognitive-behavioural case management and antidepressant medication. A secondary aim is to test biological and psychological variables that moderate and mediate response to this sequential treatment strategy.

METHODS

This is a sequential multiple assignment randomised trial (SMART) consisting of three steps: Step 1: SPS (1.5 months); Step 2: SPS vs Cognitive Behavioural Case Management (4.5 months); Step 3: Cognitive Behavioural Case Management + Antidepressant Medication vs Cognitive Behavioural Case Management + Placebo (6 months). The intervention is of 12 months duration in total and participants will be followed up at 18 months and 24 months post baseline.

CONCLUSION

This paper reports on the rationale and protocol of the Staged Treatment in Early Psychosis (STEP) study. With a large sample of 500 UHR participants this study will investigate the most effective type and sequence of treatments for improving functioning and reducing the risk of developing psychotic disorder in this clinical population.

Understanding the schizophrenia prodrome

Schizophrenia is a neurodevelopmental disorder and its course is said to have an onset much before the presentation with psychotic symptoms. Even though the concept of prodrome in schizophrenia has been accepted, there is still an existence of a diagnostic dilemma. Various imaging studies and biomarkers have also been studied for confirmation of this diagnosis. The critical period of intervention when identified clarifies the doubts about faster and better outcomes.

[Advocacy for the establishment of a comprehensive strategy to reduce the "burden" of schizophrenic disorders]

This article attempts to identify and put into perspective the different approaches that could globally prevent the suffering induced by schizophrenia, from the detection of early psychosis to the impact on individual and family functioning and emotional health. Schizophrenia causes, at the community level, a number of difficult consequences and associated costs, which likely could be reduced if specific strategies, already known and documented internationally, were applied. Two areas not explored in this article: the role of medication and the issue of suicide prevention. In the scope of screening and early treatment, genetic risk, as well as the predictive ability of the clinical criteria for individuals at "ultra-high risk" of developing schizophrenia justify an increased vigilance for the detection of symptoms in order for treatment to begin earlier and to be more effective. These risk factors should not be neglected as the benefits of early management impact the course of illness and functional outcome. At this stage of the emergence of the disorder, it is difficult to systematize a therapeutic protocol. Two options are open to the clinician: "wait and watch" given the lack of a conclusive diagnosis and a more pro-active intervention, focused on the therapeutic alliance and enhancing insight and awareness. The second approach seems more productive but requires transparency with the patient and family regarding the uncertainty of the clinical situation, and an attitude that favors sharing information, along the lines of early psych education. Once a pathological stage is reached, early and accurate clinical care is fundamental. They depend heavily on access to care, proximity and availability to clinics or out-reach teams, capable of a thorough diagnostic work-up. Yet conversely, the availability for early and accurate clinical care faces obstacles which are closely related to the pejorative view of psychiatry held by the general public, health care professionals, and public officials. This poor image of psychiatry is partly due to cases of clinical decompensation, dangerous in some instances, underscoring why it is be important to understand and anticipate the contributory factors to these outcomes in the first place so as to avoid them. In this sense, defending a complacent and conciliatory approach can be counter-productive. Following developments of recent decades in other chronic diseases (diabetes, cancer, AIDS, severe heart disease…), the implementation of systematic clinical programs, treatment protocols, psycho-education to reinforce adherence to therapeutic measures, their simplification, the support and appreciation of the role of caregivers, destigmatizing due to proximity of contact, and therefore an increase in the use of care. Similarly, the systematic search for side-effects of medication and pro-actively managing to minimize their occurrence strengthen compliance, a recognized factor of relapse prevention. Preventable comorbidities, addictions, and common physical illnesses are not systematically screened (neoplastic diseases, diabetes, hypertension, dental health, gynecology…) in this population and thus also represent significant potential for a better life expectancy. The tools of psychosocial rehabilitation, unfortunately, are too infrequently used in France. Their goal is to improve the functional outcome of patients, a determinant of social integration and to lessen the burden shouldered by family and other carers, and ultimately to reduce exacerbations of the illness due to situations of interpersonal stress. Work has also proven its worth as a protective factor, as well as strengthening a sense of self-efficiency, of self-esteem, of empowerment, of quality of life, helping attain recovery. It is clear that not all social and health care systems are primarily geared towards these objectives, although they have at their disposal, by the means described above, strong preventive measures for relapses. Beyond the issue of the implementation of clinical programs, the existing culture would benefit from being infused with a prioritization of resource deployment, with debates of these issues regarding parity for mental health services, advocated by users, and forging a place, for example, for the intervention of "peer supports", sociologists, social workers, interested beyond the disease, in community environment, employment opportunities, and housing. Overall, this work argues for updating our conceptions of clinical care, supporting the systematic implementation of modern models of care, and expanding the scope of our concerns regarding patients' lives.

Antipsychotic Treatment Reduces Indices of Oxidative Stress in First-Episode Psychosis Patients

38 first-episode psychosis (FEP) patients and 37 control subjects were recruited for the study of indices of oxidative stress (OxS). The main purpose of the study was to compare the OxS statuses (serum total antioxidant capacity (TAC), total level of peroxides (TPX), oxidative stress index (OSI), and ratio oxidized methionine (Met-SO) to methionine (Met)) between antipsychotic-naïve FEP patients and individuals without a history of psychiatric disorders. Subsequently, the impact of 7-month antipsychotic treatment was evaluated on the OxS status in FEP patients. An attempt was made to assess links between OxS signature and inflammation markers. The oxidative stress indices remained generally unchanged in antipsychotic-naïve FEP patients compared to control subjects. Despite that, there was a significant correlation between the levels of TPX and EGF (endothelial growth factor) in FEP patients. This correlation disappeared after antipsychotic treatment of FEP patients. Moreover, antipsychotic treatment was associated with a significant reduction in OxS indices, including TPX, OSI, and ratio between Met-SO and Met. By contrast, in chronic SCZ patients we established a significant high-grade OxS. In conclusion, the markers of total antioxidative capacity, lipid peroxidation, and protein oxidation revealed no high-grade OxS in FEP patients. Nevertheless, antipsychotic treatment induced a considerable anti-inflammatory effect. OxS levels were also significantly decreased if compared in FEP patients before and after antipsychotic treatment.

INCREASED INTERNET USE AND POORER ABILITY TO MANAGE EMOTIONS IN YOUTH AT HIGH-RISK FOR PSYCHOSIS

The relationship between Internet use and social behavior remains unknown. However, research indicates that Internet use (IU) may have some causal role in certain types of psychopathology and overall functioning. In contrast, other work suggests that IU may be protective and buffer against social isolation. Poorer emotional processing (EP) is characteristic of schizophrenia, and these deficits are present prior to illness onset (the ultra high-risk period (UHR)). UHR adolescents/young adults also fall within an age demographic characterized by extensive IU, which suggests that evaluating a link between IU and social behavior in this population may be especially informative. The present study examined the relationship between IU and emotional processing in 98 adolescents/young adults (52 UHR youth and 46 controls). UHR youth exhibited greater problematic IU (β = − 6.49, F(1,95) = 8.79, p = 0.002) and social withdrawal/problems resulting from this use (β = − 3.23, F(1,95) = 11.43, p < 0.001), as well deficits in emotional processing in comparison to healthy peers (β = 4.59, F(1,94) = 5.52, p = 0.011). Furthermore, the social problems resulting from IU were significantly related to the ability to process emotional information in the UHR group (β = − 0.51, t(1,48) = − 2.10, p = 0.021). UHR youth showed evidence of problematic IU relative to controls, and the social problems resulting from IU related to poorer EP. Findings replicate extant research involving other psychosis risk populations, while adding information regarding how social processes may relate to IU.

First-episode psychosis is associated with oxidative stress: Effects of short-term antipsychotic treatment

AIMS

In the present study, our aim was to investigate the oxidative-antioxidative systems in unmedicated first-episode psychosis (FEP) patients at the beginning and after short-term treatment.

METHODS

This study consisted of 29 patients who experienced an FEP and 25 control subjects. In order to investigate the oxidative status, we determined plasma malondialdehyde (MDA) levels, oxidizability of red blood cells, oxidation and oxidizability of apolipoprotein B-containing lipoproteins (apo B-basal MDA and apo B-ΔMDA). In order to evaluate the antioxidative defense, we measured serum total antioxidative capacity, uric acid, albumin, total bilirubin and vitamin E levels and serum paraoxonase/arylesterase, whole blood glutathione peroxidase (GPx) and red blood cell superoxide dismutase activities before and after 6 weeks of treatment in patients with FEP.

RESULTS

Plasma MDA and apo B-basal MDA levels and red blood cell superoxide dismutase activity were significantly higher and serum arylesterase and whole blood-GPx activities were lower in the FEP group than those of the healthy control group. There were not any significant changes in the oxidative and antioxidative system parameters (except increased vitamin E levels) after treatment.

CONCLUSIONS

The results of this study suggest that FEP is accompanied by oxidative stress. However, further studies are needed to clarify the role of oxidative stress in the physiopathologic mechanisms of FEP, so that oxidative and antioxidative system parameters can be used in the management of these patients. In accordance with psychiatric evaluation, for a better management, patients with FEP may require a multidisciplinary approach, including oxidative and antioxidative system parameters.

Omega-3 fatty acids prevent the ketamine-induced increase in acetylcholinesterase activity in an animal model of schizophrenia

AIMS

Schizophrenia is a debilitating neurodevelopmental disorder that is associated with dysfunction in the cholinergic system. Early prevention is a target of treatment to improve long-term outcomes. Therefore, we evaluated the preventive effects of omega-3 fatty acids on AChE activity in the prefrontal cortex, hippocampus and striatum in an animal model of schizophrenia.

MAIN METHODS

Young Wistar rats (30 days old) were initially treated with omega-3 fatty acids or vehicle alone. Animals received ketamine to induce an animal model of schizophrenia or saline plus omega-3 fatty acids or vehicle alone for 7 consecutive days beginning on day 15. A total of 22 days elapsed between the treatment and intervention. Animals were sacrificed, and brain structures were dissected to evaluate AChE activity and gene expression.

KEY FINDINGS

Our results demonstrate that ketamine increased AChE activity in these three structures, and omega-3 fatty acids plus ketamine showed lower values for the studied parameters, which indicate a partial preventive mechanism of omega-3 fatty acid supplementation. We observed no effect on AChE expression. Together, these results indicate that omega-3 fatty acid supplementation effectively reduced AChE activity in an animal model of schizophrenia in all studied structures. In conclusion, the present study provides evidence that ketamine and omega-3 fatty acids affect the cholinergic system, and this effect may be associated with the physiopathology of schizophrenia. Further studies are required to investigate the mechanisms that are associated with this effect.

Predictors of response to second generation antipsychotics in drug naïve patients with schizophrenia: a 1 year follow-up study in Shanghai

Response and remission are of great importance to patients with first-episode schizophrenia. Although previous researches have revealed characteristics related to medication response, there is rarely data over remission-related factors. We presume that factors correlated to response may also influence remission in 1 year treatment for first-episode schizophrenia. 398 drug-naïve patients met the criteria of schizophrenia using ICD-10 criteria were recruited from Shanghai Mental Health Center and treated with one of three second generation antipsychotics (risperidone, olanzapine or quetiapine). Patients were followed up for 1 year and assessed at 2 weeks, and then 2, 3, 6, 8 and 12 months. Severity of symptom was evaluated using the Chinese version of the Positive and Negative Syndrome Scale (PANSS). Response was defined as a reduction of 50% or more PANSS scores. The 8-item criteria of remission (proposed by the Remission of Schizophrenia Working Group) were used. Logistic regression analysis revealed that shorter duration of untreated psychosis (DUP), longer treatment time, higher baseline PANSS positive score and higher PANSS general pathological scores predicted response, and acute prodromal phase was the independent factor for remission. These results indicate baseline characters that related to response and those related to remission may be different for patients with schizophrenia.

A mechanistic approach to preventing schizophrenia in at-risk individuals

In this issue of Neuron, Schobel et al. (2013) report that excess hippocampal glutamate may cause transition to psychosis in individuals at high risk for schizophrenia. Their data has implications for prevention strategies and why stress often precipitates this transition.

Effects of omega-3 dietary supplement in prevention of positive, negative and cognitive symptoms: a study in adolescent rats with ketamine-induced model of schizophrenia

Omega-3 has shown efficacy to prevent schizophrenia conversion in ultra-high risk population. We evaluated the efficacy of omega-3 in preventing ketamine-induced effects in an animal model of schizophrenia and its effect on brain-derived neurotrophic factor (BDNF). Omega-3 or vehicle was administered in Wistar male rats, both groups at the 30th day of life for 15days. Each group was split in two to receive along the following 7days ketamine or saline. Locomotor and exploratory activities, memory test and social interaction between pairs were evaluated at the 52nd day of life. Prefrontal-cortex, hippocampus and striatum tissues were extracted right after behavioral tasks for mRNA BDNF expression analysis. Bloods for serum BDNF were withdrawn 24h after the end of behavioral tasks. Locomotive was increased in ketamine-treated group compared to control, omega-3 and ketamine plus omega-3 groups. Ketamine group had fewer contacts and interaction compared to other groups. Working memory and short and long-term memories were significantly impaired in ketamine group compared to others. Serum BDNF levels were significantly higher in ketamine plus omega-3 group. There was no difference between groups in prefrontal-cortex, hippocampus and striatum for mRNA BDNF expression. Administration of omega-3 in adolescent rats prevents positive, negative and cognitive symptoms in a ketamine animal model of schizophrenia. Whether these findings are consequence of BDNF increase it is unclear. However, this study gives compelling evidence for larger clinical trials to confirm the use of omega-3 to prevent schizophrenia and for studies to reinforce the beneficial role of omega-3 in brain protection.

Prevention of the phencyclidine-induced impairment in novel object recognition in female rats by co-administration of lurasidone or tandospirone, a 5-HT(1A) partial agonist

Hypoglutamatergic function may contribute to cognitive impairment in schizophrenia (CIS). Subchronic treatment with the N-methyl-D-aspartate receptor antagonist, phencyclidine (PCP), induces enduring deficits in novel object recognition (NOR) in rodents. Acute treatment with atypical antipsychotic drugs (APDs), which are serotonin (5-HT)(2A)/dopamine D(2) antagonists, but not typical APDs, eg, haloperidol, reverses the PCP-induced NOR deficit in rats. We have tested the ability of lurasidone, an atypical APD with potent 5-HT(1A) partial agonist properties, tandospirone, a selective 5-HT(1A) partial agonist, haloperidol, a D(2) antagonist, and pimavanserin, a 5-HT(2A) inverse agonist, to prevent the development of the PCP-induced NOR deficit. Rats were administered lurasidone (0.1 or 1 mg/kg), tandospirone (5 mg/kg), pimavanserin (3 mg/kg), or haloperidol (1 mg/kg) b.i.d. 30 min before PCP (2 mg/kg, b.i.d.) for 7 days (day1-7), followed by a 7-day washout (day 8-14). Subchronic treatment with PCP induced an enduring NOR deficit. Lurasidone (1 mg/kg) but not 0.1 mg/kg, which is effective to acutely reverse the deficit due to subchronic PCP, or tandospirone, but not pimavanserin or haloperidol, significantly prevented the PCP-induced NOR deficit on day 15. The ability of lurasidone co-treatment to prevent the PCP-induced NOR deficit was enduring and still present at day 22. The preventive effect of lurasidone was blocked by WAY100635, a selective 5-HT(1A) antagonists, further evidence for the importance of 5-HT(1A) receptor stimulation in the NOR deficit produced by subchronic PCP. Further study is needed to determine whether these results concerning mechanism and dosage can be the basis for prevention of the development of CIS in at risk populations.

Similarities in serum oxidative stress markers and inflammatory cytokines in patients with overt schizophrenia at early and late stages of chronicity

Schizophrenia (SZ) is a debilitating neurodevelopmental disorder that strikes at a critical period of a young person's life. Its pathophysiology could be the result of deregulation of synaptic plasticity, with downstream alterations of inflammatory immune processes regulate by cytokines, impaired antioxidant defense and increased lipid peroxidation. The aim of this study was to examine serum oxidative stress markers and inflammatory cytokines in early and late phases of chronic SZ. Twenty-two patients at early stage (within first 10 years of a psychotic episode), 39 at late stage (minimum 10 years after diagnosis of SZ) and their respective matched controls were included. Each subject had 5 ml blood samples collected by venipuncture to examined thiobarbituric acid-reactive substances (TBARS), total reactive antioxidant potential (TRAP), protein carbonyl content (PCC), Interleukins 6 and 10 (IL-6, IL-10) and tumor necrosis factor alpha (TNF-alpha). TBARS, IL-6 and PCC levels were significantly higher in patients with SZ at early and late stages than in controls. There were no differences for TRAP and TNF-alpha levels in patients with SZ at early and late stages than in controls. IL-10 levels were decreased in patients at late stage and a decrease trend in early stage was found. Results provided evidence consistent with comparable biological markers across chronic SZ. The concept of biochemical staging proposed by others for bipolar disorder is not seen in this cohort of patients with SZ, at least for cytokines and oxidative stress markers. Our findings reinforce the need of assessment of individuals in ultra high risk to develop psychosis and first-episode population.

Update on the development of lurasidone as a treatment for patients with acute schizophrenia

Lurasidone is a novel benzisothiazole antipsychotic drug for the treatment of schizophrenia. Of the antipsychotic drugs, lurasidone has the highest affinity for the 5-hydroxytryptamine (5-HT)₇ receptor. Lurasidone also has high affinities for the dopamine D₂, 5HT_2A, 5-HT_1A and α_2C adrenergic receptors. Moreover, lurasidone has low affinities for the α₁ adrenergic, histamine H₁ and muscarinic M₁ receptors. The involvement of 5-HT₇ receptors in cognitive processes has been suggested by both pharmacological and molecular investigations. Chronic treatment with lurasidone increases neurotrophin BDNF mRNA levels in both the hippocampus (ventral and dorsal) and prefrontal cortex under basal conditions or in response to an acute swim stress. Lurasidone may potentiate N-methyl-D-aspartate receptor (NMDAR) function through antagonistic action on 5-HT₇ receptors without a direct affinity for NMDARs. These results suggest that lurasidone treatment may be a novel approach for the prevention of the development of cognitive impairment in individuals who are at risk for schizophrenia or related disorders involving cognitive impairment. In clinical trials, treatment with lurasidone was associated with significantly greater endpoint improvement versus placebo on the Positive and Negative Syndrome Scale total score after 6 weeks among subjects receiving 80 or 160 mg. The most frequent side effects of lurasidone were akathisia, nausea, parkinsonism, dizziness and somnolence. Once-daily treatment with lurasidone at 160 mg was superior to placebo based on the composite cognitive functioning measure. Lurasidone treatment produced improvements in Montgomery–Asberg Depression Rating Scale scores at 6 weeks that were significantly greater than placebo. A limitation of this review is that the majority of the data were obtained from abstracts and posters. These sources have not been subjected to the peer review processes of medical journals; thus, the results presented in these forums may require further quality review and subsequent revision prior to final publication.

Is tinnitus an acoasm?

Tinnitus and unspecific auditory hallucinations generally known as acoasms arise from identical or at least similar cerebral structures. Both phenomena can be interpreted as signs of an over activation of neuronal networks. Several pieces of evidence to underline this hypothesis as well as its implications are discussed. It is even speculated that both clinical entities might profit from treatment strategies that are normally employed for treatment of the other.