Theory of Mind differences in older patients with early-onset and late-onset paranoid schizophrenia

The mirror mechanism in schizophrenia: A systematic review and qualitative meta-analysis

BACKGROUND

Mirror neuron system (MNS) consists of visuomotor neurons that are responsible for the mirror neuron activity (MNA), meaning that each time an individual observes another individual performing an action, these neurons encode that action, and are activated in the observer's cortical motor system. Previous studies report its malfunction in autism, opening doors to investigate the underlying pathophysiology of the disorder in a more elaborate way and coming up with new rehabilitation methods. The study of MNA function in schizophrenia patients has not been as frequent and conclusive as in autism. In this research, we aimed to evaluate the functional integrity of MNA and the microstructural integrity of MNS in schizophrenia patients.

METHODS

We included case-control studies that have evaluated MNA in schizophrenia patients compared to healthy controls using a variety of objective assessment tools. In August 2022, we searched Embase, PubMed, and Web of Science for eligible studies. We used an adapted version of the NIH Quality Assessment of Case-Control Studies tool to assess the quality of the included studies. Evidence was analyzed using vote counting methods of the direction of the effect and was tested statistically using the Sign test. Certainty of evidence was assessed using CERQual.

RESULTS

We included 32 studies for the analysis. Statistical tests revealed decreased MNA (p = 0.002) in schizophrenia patients. The certainty of the evidence was judged to be moderate. Investigations of heterogeneity revealed a possible relationship between the age and the positive symptoms of participants in the included studies and the direction of the observed effect.

DISCUSSION

This finding contributes to gaining a better understanding of the underlying pathophysiology of the disorder by revealing its possible relation to some of the symptoms in schizophrenia patients, while also highlighting a new commonality with autism.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO identifier: CRD42021236453.

Late-onset psychosis and very-late-onset-schizophrenia-like-psychosis: an updated systematic review

Psychotic disorders have long been known to be a condition that peaks during adolescence and early adulthood. A considerable proportion of patients have their first onset at or after the age of 40, but little is known about this population. The current systematic review examined the clinical presentation of late-onset psychosis (LOP) and very-late-onset-schizophrenia-like psychosis (VLOSLP) with focus on their psychopathological, neuropsychological, neurobiological, psychosocial and psychological correlates. A systematic search of studies published from 2000 to 2019 from Cochrane Library, Pubmed, Medline, Embase, PsycINFO, and Scopus yielded 27 original studies that were included in this review. Results revealed there is a dearth of empirical research on the conditions in the current literature and inconsistencies in the findings reported may be associated with the lack of uniformity in the definitions for LOP and VLOSLP. Future research on the topic shall (i) specify the onset age criteria for LOP and VLOSLP; (ii) study the conditions independently; (iii) involve a larger sample size, and iv) account for potential confounding variables. A comprehensive evaluation of the risks and benefits of pharmacological treatment may also be needed.

What Do You Have in Mind? Measures to Assess Mental State Reasoning in Neuropsychiatric Populations

Social interaction is closely associated with both functional capacity and well-being. Previous research has not only revealed evidence of social dysfunction in individuals with a wide range of psychiatric and neurological disorders but also generated an abundance of potential measures for assessing social cognition. This review explores the most popular measures used within neuropsychiatric populations to investigate the ability to recognize or reason about the mental states of others. Measures are also critically analyzed in terms of strengths and limitations to aid task selection in future clinical studies. The most frequently applied assessment tools use verbal, visual or audiovisual forms of presentation and assess recognition of mental states from facial features, self-rated empathy, the understanding of other's cognitive mental states such as beliefs and intentions, or the ability to combine knowledge of other's thoughts and emotions in order to understand subtle communications or socially inappropriate behavior. Key weaknesses of previous research include limited investigation of relationships with clinical symptoms, and underutilization of measures of everyday social functioning that offer a useful counterpart to traditional "lab" tasks. Future studies should aim to carefully select measures not only based on the range of skills to be assessed but also taking into account potential difficulties with interpretation and the need to gain insight into the application of social cognitive skills as well as ability per se. Some of the best measures include those with well-matched control trials (e.g., Yoni Task) or those that restrict the influence of verbal deficits (e.g., intentions comic strip task), elicit spontaneous mentalizing (e.g., Animations Task), and possess greater ecological validity (e.g., Movie for the Assessment of Social Cognition). Social cognitive research within psychiatric populations will be further enhanced through the development of more closely matched control tasks, and the exploration of relationships between task performance, medication, strategy use, and broader emotional and motor functions.

Cognitive Functioning in Older Adults With Schizophrenia

Cognitive deficits are thought to be a core feature in schizophrenia and have been found to be strongly associated with impairments in functioning. It is estimated that more than 70% of patients with schizophrenia have cognitive impairment. The aim of this article is to critically review the emerging literature on cognition in older adults with schizophrenia. Specifically, we address the following questions: Are there differences in cognitive functioning between older adults with schizophrenia and their healthy age peers as well as with younger people with schizophrenia? What are the factors associated with cognitive deficits and their interaction over time? What are the life course trajectories of cognitive deficits, especially in later life? Are older adults with schizophrenia more likely to develop dementia, and, if so, does it differ from other dementias? Are there pharmacological and psychosocial interventions that can successfully treat cognitive deficits in older adults with schizophrenia?

Late-onset schizophrenia: do recent studies support categorizing LOS as a subtype of schizophrenia?

PURPOSE OR REVIEW

To review recent literature about late-onset schizophrenia (LOS): schizophrenia with onset between ages 40 and 60 years. New findings are presented in the context of the previous literature.

RECENT FINDINGS

Newer studies continue to suggest that early-onset schizophrenia (EOS) and LOS share fundamental clinical features (i.e., positive symptoms, negative symptoms, functional deficits). One larger recent study confirmed earlier findings that LOS differs from EOS in several important ways, including predominance of women, lower severity of positive symptoms, and lower average antipsychotic dose requirement. However, this study did not find LOS patients were more likely to have the paranoid subtype or to have less severe negative symptoms compared with EOS patients. New neuroimaging and molecular studies are identifying possible differences in the underlying pathophysiology of EOS and schizophrenia developing in mid-life to late-life; however, more research is needed to confirm these findings and determine their significance. No studies evaluated treatment strategies specifically in LOS.

SUMMARY

LOS continues to be an understudied area. Recent studies add support to the idea that LOS may be a distinct subtype of schizophrenia. Studies designed to elucidate the pathophysiology of LOS in comparison with EOS and to assess treatment strategies in this population are needed.