Schizophrenia

OBJECTIVE: The dose-response relationships of antipsychotic drugs for schizophrenia are not well defined, but such information would be important for decision making by clinicians. The authors sought to fill this gap by conducting dose-response meta-analyses. METHODS: A search of multiple electronic databases (through November 2018) was conducted for all placebo-controlled dose-finding studies for 20 second-generation antipsychotic drugs and haloperidol (oral and long-acting injectable, LAI) in people with acute schizophrenia symptoms...

Concerns have been raised that treatment with antipsychotic medication might adversely affect long-term outcomes for people with schizophrenia. The evidence cited for these concerns includes the association of antipsychotic treatment with brain volume reduction and with dopamine receptor sensitization, which might make patients vulnerable to relapse and illness progression. An international group of experts was convened to examine findings from clinical and basic research relevant to these concerns. Little evidence was found to support a negative long-term effect of initial or maintenance antipsychotic treatment on outcomes, compared with withholding treatment...

BACKGROUND: Several studies and meta-analyses have shown that mortality in people with schizophrenia is higher than that in the general population but have used relative measures, such as standardised mortality ratios. We did a systematic review and meta-analysis to estimate years of potential life lost and life expectancy in schizophrenia, which are more direct, absolute measures of increased mortality. METHODS: We searched MEDLINE, PsycINFO, Embase, Cinahl, and Web of Science for published studies on years of potential life lost and life expectancy in schizophrenia...

Twenty years have passed since the dysconnection hypothesis was first proposed (Friston and Frith, 1995; Weinberger, 1993). In that time, neuroscience has witnessed tremendous advances: we now live in a world of non-invasive neuroanatomy, computational neuroimaging and the Bayesian brain. The genomics era has come and gone. Connectomics and large-scale neuroinformatics initiatives are emerging everywhere. So where is the dysconnection hypothesis now? This article considers how the notion of schizophrenia as a dysconnection syndrome has developed - and how it has been enriched by recent advances in clinical neuroscience...

IMPORTANCE: Absolute and relative risks of violence are increased in patients with psychotic disorders, but the contribution of triggers for violent acts to these risks is uncertain. OBJECTIVE: To examine whether a range of triggers for violent acts are associated with risks of violence in patients diagnosed with psychotic disorders and in individuals without a psychiatric diagnosis. DESIGN, SETTING, AND PARTICIPANTS: Using a sample of all individuals born in Sweden between 1958 and 1988 (N = 3 123 724), we identified patients in the National Patient Register who were diagnosed with schizophrenia spectrum disorders (n = 34 903) and bipolar disorder (n = 29 692), as well as unaffected controls (n = 2 763 012)...

BACKGROUND: Although clozapine is the 'gold standard' for treatment-refractory schizophrenia, meta-analyses of clozapine for this condition are lacking. AIMS: We conducted a systematic review and meta-analysis of clozapine treatment for people with treatment-refractory schizophrenia. METHOD: We searched the Cochrane Schizophrenia Group's trial register, PubMed and EMBASE and hand-searched key papers for randomised controlled trials of clozapine for treatment-refractory schizophrenia...

Schizophrenia is a complex, heterogeneous behavioural and cognitive syndrome that seems to originate from disruption of brain development caused by genetic or environmental factors, or both. Dysfunction of dopaminergic neurotransmission contributes to the genesis of psychotic symptoms, but evidence also points to a widespread and variable involvement of other brain areas and circuits. Disturbances of synaptic function might underlie abnormalities of neuronal connectivity that possibly involves interneurons, but the precise nature, location, and timing of these events are uncertain...

OBJECTIVE: Auditory verbal hallucinations (AVHs) are core features of psychotic illness and remain significant in predicting poor outcome and risk. There has been a wide range of approaches to understanding these experiences. METHOD: A systematic literature review summarizing different methods of investigation and their results; phenomenology, descriptive psychopathology, psychological, cognitive neurobiology, and neuroimaging. RESULTS: A number of 764 papers and texts were screened and 113 reviewed...

IMPORTANCE: Although adults with schizophrenia have a significantly increased risk of premature mortality, sample size limitations of previous research have hindered the identification of the underlying causes. OBJECTIVE: To describe overall and cause-specific mortality rates and standardized mortality ratios (SMRs) for adults with schizophrenia compared with the US general population. DESIGN, SETTING, AND PARTICIPANTS: We identified a national retrospective longitudinal cohort of patients with schizophrenia 20 to 64 years old in the Medicaid program (January 1, 2001, to December 31, 2007)...

Schizophrenia (SZ) is a devastating psychiatric condition affecting numerous brain systems. Recent studies have identified genetic factors that confer an increased risk of SZ and participate in the disease etiopathogenesis. In parallel to such bottom-up approaches, other studies have extensively reported biological changes in patients by brain imaging, neurochemical and pharmacological approaches. This review highlights the molecular substrates identified through studies with SZ patients, namely those using top-down approaches, while also referring to the fruitful outcomes of recent genetic studies...

Individuals with schizophrenia exhibit impaired social cognition, which manifests as difficulties in identifying emotions, feeing connected to others, inferring people's thoughts and reacting emotionally to others. These social cognitive impairments interfere with social connections and are strong determinants of the degree of impaired daily functioning in such individuals. Here, we review recent findings from the fields of social cognition and social neuroscience and identify the social processes that are impaired in schizophrenia...

Schizophrenia is a complex neuropsychiatric disorder that is associated with persistent psychosocial disability in affected individuals. Although studies of schizophrenia have traditionally focused on deficits in higher-order processes such as working memory and executive function, there is an increasing realization that, in this disorder, deficits can be found throughout the cortex and are manifest even at the level of early sensory processing. These deficits are highly amenable to translational investigation and represent potential novel targets for clinical intervention...

Schizophrenia is a disease of abnormal brain development. Considerable evidence now indicates that environmental factors have a causative role in schizophrenia. Elevated incidence of the disease has been linked to a wide range of disturbances in the prenatal environment and to social factors and drug intake during adolescence. Here we examine neurodevelopment of the prefrontal cortex in the first trimester of gestation and during adolescence to gain further insight into the neurodevelopmental processes that may be vulnerable in schizophrenia...

In the past decade, there has been renewed interest in immune/inflammatory changes and their associated oxidative/nitrosative consequences as key pathophysiological mechanisms in schizophrenia and related disorders. Both brain cell components (microglia, astrocytes, and neurons) and peripheral immune cells have been implicated in inflammation and the resulting oxidative/nitrosative stress (O&NS) in schizophrenia. Furthermore, down-regulation of endogenous antioxidant and anti-inflammatory mechanisms has been identified in biological samples from patients, although the degree and progression of the inflammatory process and the nature of its self-regulatory mechanisms vary from early onset to full-blown disease...

BACKGROUND: Behavioral phenotypical continua from health to disease suggest common underlying mechanisms with quantitative rather than qualitative differences. Until recently, autism spectrum disorders and schizophrenia were considered distinct nosologic entities. However, emerging evidence contributes to the blurring of symptomatic and genetic boundaries between these conditions. The present study aimed at quantifying behavioral phenotypes shared by autism spectrum disorders and schizophrenia to prepare the ground for biological pathway analyses...

Cognitive deficits are a core clinical feature of schizophrenia but respond poorly to available medications. Thus, understanding the neural basis of these deficits is crucial for the development of new therapeutic interventions. The types of cognitive processes affected in schizophrenia are thought to depend on the precisely timed transmission of information in cortical regions via synchronous oscillations at gamma band frequency. Here, we review 1) data from clinical studies suggesting that induction of frontal cortex gamma oscillations during tasks that engage cognitive or complex perceptual functions is attenuated in schizophrenia; 2) findings from basic neuroscience studies highlighting the features of parvalbumin-positive interneurons that are critical for gamma oscillation production; and 3) results from recent postmortem human brain studies providing additional molecular bases for parvalbumin-positive interneuron alterations in prefrontal cortical circuitry in schizophrenia...

One hundred years after its conceptual definition as 'Dementia Praecox' by Emil Kraepelin, schizophrenia is still a serious psychiatric illness that affects young adults and leads to disability in at least half of patients. The key treatment issue is partial or non-response, especially of negative symptoms. The illness is also associated with different degrees of cognitive dysfunction, particularly in verbal and working memory; the resulting functional impairment may lead to unemployment and an inability to maintain stable relationships...

IMPORTANCE: Schizophrenia has a complex etiology influenced both by genetic and nongenetic factors but disentangling these factors is difficult. OBJECTIVE: To estimate (1) how strongly the risk for schizophrenia relates to the mutual effect of the polygenic risk score, parental socioeconomic status, and family history of psychiatric disorders; (2) the fraction of cases that could be prevented if no one was exposed to these factors; (3) whether family background interacts with an individual's genetic liability so that specific subgroups are particularly risk prone; and (4) to what extent a proband's genetic makeup mediates the risk associated with familial background...

Within the field of mental health, the concept of predisposition or that of being "at risk" has been properly addressed by Mrazek and Haggarty. This period prior to clear diagnosis of psychosis has been referred by several names like 'premorbid' phase, at-risk individuals, predisposed individuals, prodromal phase, etc. The premorbid phase is perhaps the most debated term in this list because this term suggests that the morbidity arises only in the overt illness phase. However, evidences arising from several different lines of observations suggest that this may not be the case...

The search for clinical outcome predictors for schizophrenia is as old as the field of psychiatry. However, despite a wealth of large, longitudinal studies into prognostic factors, only very few clinically useful outcome predictors have been identified. The goal of future treatment is to either affect modifiable risk factors, or use nonmodifiable factors to parse patients into therapeutically meaningful subgroups. Most clinical outcome predictors are nonspecific and/or nonmodifiable. Nonmodifiable predictors for poor odds of remission include male sex, younger age at disease onset, poor premorbid adjustment, and severe baseline psychopathology...