Cognitive functions and psychopathological symptoms in early-onset schizophrenia

Videogame training increases clinical well-being, attention and hippocampal-prefrontal functional connectivity in patients with schizophrenia

Recent research shows that videogame training enhances neuronal plasticity and cognitive improvements in healthy individuals. As patients with schizophrenia exhibit reduced neuronal plasticity linked to cognitive deficits and symptoms, we investigated whether videogame-related cognitive improvements and plasticity changes extend to this population. In a training study, patients with schizophrenia and healthy controls were randomly assigned to 3D or 2D platformer videogame training or E-book reading (active control) for 8 weeks, 30 min daily. After training, both videogame conditions showed significant increases in sustained attention compared to the control condition, correlated with increased functional connectivity in a hippocampal-prefrontal network. Notably, patients trained with videogames mostly improved in negative symptoms, general psychopathology, and perceived mental health recovery. Videogames, incorporating initiative, goal setting and gratification, offer a training approach closer to real life than current psychiatric treatments. Our results provide initial evidence that they may represent a possible adjunct therapeutic intervention for complex mental disorders.

Developmental and symptom profiles in early-onset psychosis

Psychotic disorders in children are more heterogeneous than is captured by categorical diagnoses. In a new cohort of children and adolescents, we evaluated the relationships among age at onset (AAO), clinical symptoms and developmental impairments. Patients with schizophrenia and other "spectrum" psychotic diagnoses (N = 88; AAO 6-17, mean 12.6) were evaluated with diagnostic interviews, a new clinical scale (Lifetime Dimensions of Psychosis Scale-Child and Adolescent), and neuropsychological and medical evaluations. Key findings were replicated in an adult cohort of 2420 cases, including 127 with retrospective AAO<13. Factor and cluster analyses were carried out to identify clinical profiles. Five clinical factors were identified in each cohort: Positive, Bizarre Positive, Negative/Formal Thought Disorder, Depression and Mania. Earlier AAO predicted severity of bizarre positive symptoms in children and of bizarre and other symptoms in adults. Four clinical clusters in the child cohort were characterized by: more severe bizarre positive symptoms (N = 31); negative symptoms (N = 15); premorbid autism spectrum features and developmental delay (N = 12); and depressive symptoms with heterogeneous diagnoses and mild positive/negative symptoms (N = 25). Previous factor-analytic studies of childhood psychosis did not specifically consider bizarre positive symptoms. Here, bizarre positive symptoms emerged as clinical markers of severe, childhood-onset psychosis similar to adult schizophrenia. The four clusters are clinically meaningful and useful for treatment planning and potentially for biological research. Childhood-onset cases are rare and thus difficult to study, but additional, larger cohorts may be useful in dissecting the biological and developmental heterogeneity of psychotic disorders.

Smoking does not impact social and non-social cognition in patients with first episode psychosis

BACKGROUND

Many studies having shown significant improvements in non-social and social cognitive performance in smoking FEP patients compared to non-smoking FEP patients. The findings are controversial. This study analyzed the effects of tobacco use on non-social and social cognitive function in a large group of FEP patients and a matched healthy control group.

METHODS

A sample of 335 patients with FEP and 253 healthy controls was divided into four subgroups: control tobacco users (CTU), control non-tobacco users (CNTU), patient tobacco users (PTU) and patient non-tobacco users (PNTU). Demographic variables, tobacco use variables (presence or absence, frequency and duration of tobacco use), neurocognitive (non-social) performance and social cognition were assessed.

RESULTS

Comparison of 4 subgroups in non-social cognitive function revealed significant differences after controlling for covariables in executive functions (F=13.45; p≤0.001) and working memory domains (F=4.30; p=0.005). CTU and CNTU subgroups scored higher in all the domains compared to the PTU and the PNTU subgroups respectively. Social cognitive function was also significantly different within the four subgroups, with control subgroups showing better social cognition than patient subgroups. Significant differences in the executive functions domain were observed when comparing PTU and CTU groups (F=19.60; p≤0.001). No significant differences were revealed in the comparison between the patient groups.

CONCLUSIONS

This large study suggests that tobacco use in FEP patients is not related to better non-social or social cognitive performance.

Symptom dimensions and subgroups in childhood-onset schizophrenia

OBJECTIVE

This study investigated symptom dimensions and subgroups in the National Institute of Mental Health (NIMH) childhood-onset schizophrenia (COS) cohort and their similarities to adult-onset schizophrenia (AOS) literature.

METHOD

Scores from the Scales for the Assessment of Positive and Negative Symptoms (SAPS & SANS) from 125 COS patients were assessed for fit with previously established symptom dimensions from AOS literature using confirmatory factor analysis (CFA). K-means cluster analysis of each individual's scores on the best fitting set of dimensions was used to form patient clusters, which were then compared using demographic and clinical data.

RESULTS

CFA showed the SAPS & SANS data was well suited to a 2-dimension solution, including positive and negative dimensions, out of five well established models. Cluster analysis identified three patient groups characterized by different dimension scores: (1) low scores on both dimensions, (2) high negative, low positive scores, and (3) high scores on both dimensions. These groups had different Full scale IQ, Children's Global Assessment Scale (CGAS) scores, ages of onset, and prevalence of some co-morbid behavior disorders (all p<3.57E-03).

CONCLUSION

Our analysis found distinct symptom-based subgroups within the NIMH COS cohort using an established AOS symptom structure. These findings confirm the heterogeneity of COS and were generally consistent with AOS literature.

Schizophrenia and risk of dementia: a meta-analysis study

BACKGROUND

Evidence suggests that schizophrenia may be associated with an increased risk of dementia, but results from prior studies have been inconsistent. This study aimed to estimate the relationship between schizophrenia and incident dementia using a quantitative meta-analysis.

METHODS

Several databases were used to gather relevant information, including PubMed, Embase, and Web of Science, with the publication date of articles limited up to December 23, 2017. All studies reported a multivariate-adjusted estimate, represented as relative risk (RR) with 95% confidence intervals (CIs), for the association between schizophrenia and risk of dementia incidence. Pooled RRs were calculated using a random-effects model.

RESULTS

Six studies met our inclusion criteria for this meta-analysis, which included 206,694 cases of dementia and 5,063,316 participants. All individuals were without dementia at baseline. Overall, the quantitative meta-analysis suggested that subjects with schizophrenia were associated with a significantly greater risk of dementia incidence (RR 2.29; 95% CI 1.35-3.88) than those without.

CONCLUSION

The results of this meta-analysis indicate that individuals with schizophrenia may have an increased risk for the development of dementia. Future studies should explore whether schizophrenia is a modifiable risk factor for dementia.

Facial, vocal and cross-modal emotion processing in early-onset schizophrenia spectrum disorders

Recognition of emotional expressions plays an essential role in children's healthy development. Anomalies in these skills may result in empathy deficits, social interaction difficulties and premorbid emotional problems in children and adolescents with schizophrenia. Twenty-six subjects with early onset schizophrenia spectrum (EOSS) disorders and twenty-eight matched healthy controls (HC) were instructed to identify five basic emotions and a neutral expression. The assessment entailed presenting visual, auditory and congruent cross-modal stimuli. Using a generalized linear mixed model, we found no significant association for handedness, age or gender. However, significant associations emerged for emotion type, perception modality, and group. EOSS patients performed worse than HC in uni- and cross-modal emotional tasks with a specific negative emotion processing impairment pattern. There was no relationship between emotion identification scores and positive or negative symptoms, self-reported empathy traits or a positive history of developmental disorders. However, we found a significant association between emotional identification scores and nonverbal communication impairments. We conclude that cumulative dysfunctions in both nonverbal communication and emotion processing contribute to the social vulnerability and morbidity found in youths who display EOSS disorder.

Subtyping first-episode non-affective psychosis using four early-course features: potentially useful prognostic information at initial presentation

AIM

Heterogeneity of symptoms, course and outcomes in primary psychotic disorders complicates prognosis, treatment and diverse aspects of research. This study aimed to identify interpretable subtypes of first-episode non-affective psychosis based on four early-course features (premorbid academic functioning, premorbid social functioning, duration of the prodrome and age at onset of psychosis).

METHODS

Data from 200 well-characterized patients hospitalized in public-sector inpatient units for first-episode non-affective psychosis were used in latent profile analyses. Derived subtypes were then compared along a number of clinical dimensions using analyses of variance.

RESULTS

Using four early-course features, three classes were derived. A good premorbid/short prodrome subtype was characterized by a lower severity of positive symptoms, better social/occupational/global functioning, and a shorter duration of untreated psychosis; a poor premorbid/early onset subtype demonstrated greater negative and preoccupation symptoms, as well as greater psychosocial problems; and a long prodrome/late onset subtype was characterized by greater dysphoric symptoms.

CONCLUSIONS

Findings indicate a need for further research with first-episode samples on the utility of subtyping based on early-course (premorbid, prodromal and onset-related) characteristics. Such efforts could enhance the parsing of heterogeneity, thereby advancing clinical practice and research.

Cognition and communication dysfunctions in early-onset schizophrenia: effect of risperidone

BACKGROUND

Cognitive impairment and formal thought disorder, also referred to as communication disturbances, are considered the core symptoms of schizophrenia, strongly affecting social functioning and long-term outcome. Several studies in adult patients suggest improvement of both functions after the treatment with atypical antipsychotic drugs. Such medications are also used as first line treatment in early-onset schizophrenia, however their efficacy in cognitive and communication domains in this population have not been systematically assessed.

AIM OF THE STUDY

Evaluation of risperidone efficacy at psychopathological symptoms, cognitive impairment and formal thought disorder in adolescents with schizophrenia spectrum diagnosis.

MATERIAL AND METHOD

Psychopathological symptoms, cognitive functioning and formal thought disorder were evaluated in 32 hospitalized adolescent patients with schizophrenia spectrum diagnosis at the beginning of risperidone treatment and after clinical improvement and compared to the results of matched healthy control group.

RESULTS

Risperidone treatment was associated with reduction of symptom severity and moderate improvement of formal thought disorder and some aspects of executive functions. Working memory and verbal fluency were not improved. There were few correlations between psychopathological symptoms and results of cognitive tests, mainly between negative symptoms and executive functions.

DISCUSSION

In early-onset schizophrenia spectrum disorders atypical antipsychotic treatment is associated with alleviation of symptoms and only selective and moderate cognitive and communication improvement.

Is there evidence for late cognitive decline in chronic schizophrenia?

Schizophrenia (SZP) has been historically referred to as "dementia praecox" because of the recognition that its onset is associated with deficits in memory, attention and visuospatial orientation. We wondered whether there is evidence for additional cognitive decline late in the course of chronic SZP. This review examined the evidence (1) for cognitive decline late in the course of chronic SZP, (2) for how often the late cognitive decline occurs, and (3) whether the cognitive decline in late-life SZP is related to pathophysiology of SZP versus the superimposition of another type of dementia. A PUBMED search was performed combining the MESH terms schizophrenia and dementia, cognitive decline, cognitive impairment and cognitive deficits. A manual search of article bibliographies was also performed. We included longitudinal clinical studies employing standard tests of cognition. Cross-sectional studies and those that did not test cognition through standard cognitive tests were excluded. The initial search produced 3898 studies. Employing selection criteria yielded twenty-three studies. Our data extraction tool included the number of patients in the study, whether a control group was present, the age of patients at baseline and follow-up, the study setting (inpatients versus outpatients), the cognitive tests employed, study duration, and results. Only three longitudinal studies tested for dementia using Diagnostic and statistical manual of mental disorder (DSM) or International classification of disease (ICD) criteria and compared them to controls: two studies demonstrated an increase in the prevalence of dementia and one did not. Twenty longitudinal studies tested for one or more cognitive domains without employing standard criteria for dementia: twelve studies demonstrated a heterogeneous pattern of cognitive decline and eight did not. Studies generally did not control for known risk factors for cognitive impairment such as education, vascular risk factors, apolipoprotein (ApoE) genotype and family history. The evidence for late cognitive decline in SZP is mixed, but, slightly more studies suggest that it occurs. If it occurs, it is unclear whether it is related to SZP or other risks for cognitive impairment. Hence, prospective, longitudinal, controlled studies are needed to confirm that there is progressive cognitive decline in chronic SZP which occurs independent of other risk factors for cognitive impairment.

Processing speed and executive functions predict real-world everyday living skills in adolescents with early-onset schizophrenia

Cognition and clinical variables are known to be among the most predictive factors of real-world social functioning and daily living skills in adult-onset schizophrenia. Fewer studies have focused on their impact in adolescents with early-onset schizophrenia (EOS). The aim of this study is to examine the relationships and the predictive value of cognition and clinical variables on real-world daily living skills in a sample of adolescents with EOS. Cognitive, clinical and real-world everyday living skills measures were administered to 45 clinically and pharmacologically stabilized adolescent outpatients with EOS and 45 healthy control subjects matched by age and sex. Multi-variant analyses to compare cognitive and real-world functioning profiles between patients and controls and regression analysis to identify predictors of real-world functioning scores in patients were used. Adolescents with EOS showed a generalized cognitive and real-world daily living skills dysfunction. Several cognitive and clinical variables significantly correlated with real-world daily living skills functioning but only the processing speed and executive functions emerged as independent predictors of everyday living skills scores, explaining 25.1% of the variance. Slowness in processing information and executive dysfunction showed a significant impact on real-world daily living skills in EOS, independently from clinical symptoms and other cognitive variables. Nevertheless, much of the variance in the daily living skills measure remained unaccounted for, suggesting that other factors were involved as well in this young population.

Movement-related potentials point towards an impaired tuning of reafferent sensory feedback by preceding motor activation in schizophrenia

The link between focal motor system activation and reafferent sensory feedback is thought to be crucial for the perception that a movement is actively performed. In this article, we examine how schizophrenia affects the relationship between motor and somatosensory system activation. Movement-related potential source analysis allowed us to separate and compare motor activation deficits and reafferent feedback processing. We analyzed lateralized movement-related potentials during choice reaction movements in 16 subjects with schizophrenia/schizoaffective disorder. These subjects had partial remissions with predominantly negative symptoms and were compared to an age-matched healthy control group. In the schizophrenia/schizoaffective group, dipole source analysis indicated a significantly reduced lateralized sensorimotor activation immediately preceding movement execution. In contrast, activation by reafferent feedback was relatively unimpaired. Subjects with schizophrenia/schizoaffective disorder lacked a focal motor and reafferent sensory processing correlation, which can be identified through a significantly different regression slope from healthy controls. Reduced action-related motor system activation in subjects with schizophrenia/schizoaffective disorder was associated with preserved activation by reafferent sensory feedback. Most importantly, motor-sensory tuning, i.e. a specific enhancement of sensory information necessary to monitor movements, could not be found in subjects with schizophrenia/schizoaffective disorder. Our data provide further evidence for disturbed motor-sensory interactions in schizophrenia.

Neurobiology and phenotypic expression in early onset schizophrenia

AIM

Early-onset schizophrenia (onset before adulthood) is a rare and severe form of the disorder that shows phenotypic and neurobiological continuity with adult-onset schizophrenia. Here, we provide a synthesis of keynote findings in this enriched population to understand better the neurobiology and pathophysiology of early-onset schizophrenia.

METHODS

A synthetic and integrative approach is applied to review studies stemming from epidemiology, phenomenology, cognition, genetics and neuroimaging data. We provide conclusions and future directions of research on early-onset schizophrenia.

RESULTS

Childhood and adolescent-onset schizophrenia is associated with severe clinical course, greater rates of premorbid abnormalities, poor psychosocial functioning and increased severity of brain abnormalities. Early-onset cases show similar neurobiological correlates and phenotypic deficits to adult-onset schizophrenia, but show worse long-term psychopathological outcome. Emerging technological advances have provided important insights into the genomic architecture of early-onset schizophrenia, suggesting that some genetic variations may occur more frequently and at a higher rate in young-onset than adult-onset cases.

CONCLUSIONS

Clinical, cognitive, genetic and imaging data suggest increased severity in early-onset schizophrenia. Studying younger-onset cases can provide useful insights into the neurobiological mechanisms of schizophrenia and the complexity of gene-environment interactions leading to the emergence of this debilitating disorder.

Deficient maturation of aspects of attention and executive functions in early onset schizophrenia

The few existing long-term, neuropsychological follow-up studies of early onset schizophrenia (EOS) patients have reported relative stability in some cognitive functions but abnormal developmental trajectories in verbal memory, set shifting, aspects of attention, and speed of information processing throughout late adolescence into early adulthood. The current 5-year follow-up study compared the development of specific cognitive functions in EOS patients (N = 17) from the time of first-episode to chronic phase with that of healthy controls (N = 38) and secondarily to patients with other early onset, non-organic, non-affective psychoses (EOP) (N = 11). Speed of processing of executive functions, set shifting, and attention improved significantly in the healthy controls and reflected continuous functional maturation during late adolescence and early adulthood. The developmental progression of attention and set shifting but not speed of processing of executive functions was significantly subnormal in EOS patients. Other specific cognitive functions that had attained functional maturity in the healthy controls before or around the time of the baseline assessment showed normal development in EOS patients during the follow-up period, indicating stable cognitive deficits. These results suggest post-onset developmental deficits in two out of the three aspects of attention and executive functions that have protracted maturational trajectories and that overlap the age of onset of EOS. No significant difference in the development of any specific cognitive function was found between the EOS and EOP group.

Course of intelligence deficits in early onset, first episode schizophrenia: a controlled, 5-year longitudinal study

Only few prospective longitudinal studies have assessed the course of intelligence deficits in early onset schizophrenia (EOS), and these have used different age appropriate versions of Wechsler Intelligence Scales and age appropriate norms. The post-psychotic development of intelligence in EOS has predominantly been characterized as relatively stable in these studies. However, comparisons of IQs from different test versions based on the different norms may not permit unequivocal interpretations. The objective of the current study was to compare the development of intelligence in EOS patients (N = 10) from their first psychotic episode to 5 years of post onset with that of healthy controls (N = 35) and patients who at baseline had been diagnosed with other non-affective psychoses (N = 8). The same version of a Wechsler Intelligence Scale was administered at both baseline and follow-up assessments, and the same norms were used to derive IQs at baseline and follow-up. Significantly smaller change in mean full scale intelligence quotient (FSIQ) was found in diagnostically stable EOS patients compared with healthy controls during the follow-up period. However, no statistically significant difference in mean FSIQ change was observed between patients with EOS and patients with other non-affective psychoses, although this result must be interpreted with caution due to the small sample sizes. The results suggest abnormally slow acquisition of new intellectual information and skills in EOS patients during the first 5 years after full clinical presentation.

Symptomatology and neuropsychological functioning in cannabis using subjects at ultra-high risk for developing psychosis and healthy controls

OBJECTIVE

The relationship between cannabis use and psychosis has been studied intensively. Few data, however, are available on the relationship between cannabis use, ultra-high risk for developing psychosis and neurocognition. The aim of the present cross-sectional study was therefore to investigate the relationship between cannabis use, ultra-high-risk (UHR) symptoms and cognitive functioning in UHR patients and healthy controls.

METHODS

A total of 63 ultra-high-risk patients (34 cannabis users) and 58 control subjects (28 cannabis users) were assessed with clinical measures and a neuropsychological test battery. Patients were eligible for the study if they were between the ages of 12 and 35 years and if they fell into one or more of the following inclusion groups: familial risk and reduced functioning, attenuated psychotic symptoms, brief limited intermittent psychotic symptoms and basic symptoms. Control subjects were eligible for the study if they were between the ages 12 and 35, had no present or past psychiatric illness, no family history of psychiatric illness, no drug use in the non-cannabis-using group, and use of at least four joints per week in the cannabis-using control group.

RESULTS

In the UHR and the control group, cannabis users experienced more basic symptoms and UHR symptoms than the non-cannabis users. Moreover, cannabis users in the control group performed at the level of the UHR subjects on a test of verbal memory and verbal fluency. Frequency of cannabis use correlated with severity of several UHR symptoms.

CONCLUSIONS

Cannabis-using UHR patients have more basic symptoms than non-using patients. In addition, healthy cannabis users have more subclinical UHR and basic symptoms and more neuropsychological dysfunctions than non-cannabis users. More frequent cannabis use was related to increased severity of certain UHR symptoms.

Measuring changes in functional status among patients with schizophrenia: the link with cognitive impairment

Cognitive impairment associated with schizophrenia (CIAS) includes neuropsychological deficits in attention, working memory, verbal learning, and problem solving. These deficits have been shown to be linked to impairment in functional status (eg, social behavior, work performance, and activities of daily living) among patients with schizophrenia in cross-sectional studies. Less is known about the relationship between cognitive and functional change over time, such as potential functional implications of treatment-related improvement in CIAS. The purpose of this review is to summarize research on the association between change in CIAS and change in functional status, to discuss responsiveness of functional outcomes measures, and to provide recommendations for future research and measure development. Nine longitudinal studies were located on the link between CIAS and functional status, and 8 functional outcomes measures were used across these studies. The 9 studies offer initial support for a link between change in cognitive function and change in functional status. However, inconsistent findings across studies indicate that available research is preliminary, and substantial questions remain unanswered. Shortcomings of functional status measures are noted: most instruments were not developed for the target population, and none have demonstrated responsiveness to cognitive change among schizophrenic patients. It is recommended that new functional outcome measures be developed that are specifically designed to be responsive to change in cognition, with domains previously shown to be related to cognitive ability. When creating new functional outcomes measures for assessment of patients with schizophrenia, responsiveness to change in CIAS should be evaluated as part of the development and validation process.

Psychopathological dimensions in childhood and adolescent psychoses: a confirmatory factor analytical study

The present study explored psychopathological dimensions in psychoses of children and adolescents and the distribution of demographic and clinical variables across different psychopathological domains. This study included 101 consecutive patients aged 6-18 years who had a DSM-IV psychotic disorder (schizophrenia and related disorders or mood disorders). Exclusion criteria included presence of organicity, substance use disorders, and any other childhood disorder. Psychopathology was assessed with Scales for Assessment of Positive and Negative Symptoms. Analysis revealed a four-factor model comprising primary negative, secondary negative, manic and paranoid factors. Patients were regrouped into one of the four factors based on their symptomatology. Patients in these four groups differed in education and age of onset and duration of illness. This study confirmed the existence of a factor structure in psychoses of children and adolescents.

Reconsidering the classification of schizophrenia and manic depressive illness--a critical analysis and new conceptual model

The idea of 'disease entity' in psychiatry and the nosologic map of insanity with the distinction between dementia praecox (schizophrenia since Bleuler 1911) and manic depressive insanity, originally developed by Emil Kraepelin (1986), is an important landmark in the history of psychiatry (Jablensky 1995). This classification, however, has been vigorously debated throughout the years, and new evidence emerging from epidemiological, clinical, genetic and biological research demonstrates that the two nosological categories have distinct features as well as share many similarities in their risk factors, genetic predisposition, brain pathology, neurophysiology, clinical phenomenology and response to treatment, thus raising questions about the validity of the categorical classification of psychoses. In this paper we examine some of the similarities and differences between schizophrenia and bipolar illness emerging from recent biological and clinical research and attempt to clarify major inherent logical contradictions in the application of the 'disease' model of psychiatric diagnosis to the categorical classification of schizophrenia and bipolar illness. Then we examine how similar predicaments have been resolved in other natural classification systems, namely the biological classification of species and the periodic table of the elements. Finally we propose a hypothetical conceptual approach to the classification of psychoses that has been greatly informed by the organizing principle underlying the periodic table of the elements, and is distinct from the 'disease' model of psychiatric classification.

Symptom factors in early-onset psychotic disorders

OBJECTIVE

To examine the factor structure of symptom ratings in early-onset psychotic illnesses.

METHOD

Subjects were drawn from a 2-year prospective study of early onset psychotic disorders. Principal components analysis with orthogonal (varimax) rotation was used to create factors from baseline ratings on the Schedule for Positive Symptoms, the Schedule for Negative Symptoms, and the Brief Psychiatric Rating Scale for Children.

RESULTS

Youths with schizophrenia (n = 27), bipolar disorder (n = 22), and psychosis not otherwise specified (n = 20) were included. Four symptom factors were identified: negative symptoms, positive symptoms, behavioral problems, and dysphoria. Negative symptoms were predictive of the diagnosis of schizophrenia and treatment with antipsychotic medications. Neither behavior problems nor dysphoria were predictive of diagnosis. In subjects who completed follow-up assessments at year 1 (n = 49) and year 2 (n = 39), negative symptoms and behavioral problems predicted poorer functioning.

CONCLUSIONS

The four factors are clinically relevant, with both treatment planning and prognostic implications. Negative symptoms best differentiated schizophrenia from the other disorders. Behavior problems and dysphoria were nonspecific problems that occurred in all three disorders, which likely leads to misdiagnosis in community settings.