The relationship between Asperger's syndrome and schizophrenia in adolescence

Prevalence of autism in first-episode psychosis in two Hong Kong teaching hospitals

LAY ABSTRACT

Autistic features are commonly observed in children and adolescents with first-episode psychosis, but they are sometimes overlooked by clinicians and caregivers. By comprehensively examining the clinical profiles of 103 children and adolescents (below 18 years old) with first-episode psychosis and conducting the Autism Diagnostic Interview-Revised (the 'gold standard' autism diagnostic tool) with their primary caregivers, we showed that around 28% of patients with first-episode psychosis had a comorbid autism diagnosis, and boys were 3.57 times more likely to have first-episode psychosis-autism spectrum disorder comorbidity than girls. After administering the Autism Diagnostic Interview-Revised, we also observed that an additional 30% of patients with first-episode psychosis met the autism spectrum disorder diagnostic cut-off; their autism spectrum disorder symptoms were probably overshadowed by prodromal psychotic symptoms and left undetected before this study. The co-occurrence of autism and first-episode psychosis might be more common than we previously thought. Careful autism screening and assessment is highly recommended for clinicians working with patients with psychosis.

Case report: C1/2 rotational instability progressing to extreme subaxial hyperkyphosis in an adolescent with severe catatonia

Introduction

Autism spectrum disorder (ASD) is characterized by deficits in social communication, repetitive behaviors, and can be accompanied by a spectrum of psychiatric symptoms, such as schizophrenia and catatonia. Rarely, these symptoms, if left untreated, can result in spinal deformities.

Research question and case description

This case report details the treatment of a 16-year-old male ASD patient with catatonic schizophrenia and mutism, presenting with neck pain, left-rotated torticollis, and fever. MRI revealed atlantoaxial rotational instability and spinal cord compression from a dislocated dens axis. After inconclusive biopsies, empirical antibiotics, hard collar and halo fixation treatment, persistent instability necessitated C1/2 fusion. The ongoing catatonia was addressed with electroconvulsive therapy. Concurrently, he developed severe subaxial hyperkyphosis. The report examines the decision-making between conservative and surgical management for an adolescent with significant psychiatric comorbidity and progressive spinal symptoms against a backdrop of uncertain etiology.

Materials and methods

A case report and review of the literature.

Results

Posterior C1-C7 stabilization was successfully executed, effectively restoring cervical sagittal alignment, which was maintained throughout a two-year follow-up. Concurrently, the catatonia resolved.

Discussion and conclusion

To our knowledge, this is the third reported case of severe cervical deformity associated with fixed posture in a psychiatric patient. This case report emphasizes the critical importance of multidisciplinary collaboration in managing the interplay between neuropsychiatric disorders and severe spinal deformities. It showcases the practicality and efficacy of surgical intervention for persistent cervical deformity in pediatric schizophrenia patients, highlighting the necessity for a comprehensive risk-benefit analysis.

Shared and distinct white matter abnormalities in adolescent-onset schizophrenia and adolescent-onset psychotic bipolar disorder

BACKGROUND

While adolescent-onset schizophrenia (ADO-SCZ) and adolescent-onset bipolar disorder with psychosis (psychotic ADO-BPD) present a more severe clinical course than their adult forms, their pathophysiology is poorly understood. Here, we study potentially state- and trait-related white matter diffusion-weighted magnetic resonance imaging (dMRI) abnormalities along the adolescent-onset psychosis continuum to address this need.

METHODS

Forty-eight individuals with ADO-SCZ (20 female/28 male), 15 individuals with psychotic ADO-BPD (7 female/8 male), and 35 healthy controls (HCs, 18 female/17 male) underwent dMRI and clinical assessments. Maps of extracellular free-water (FW) and fractional anisotropy of cellular tissue (FAT) were compared between individuals with psychosis and HCs using tract-based spatial statistics and FSL's Randomise. FAT and FW values were extracted, averaged across all voxels that demonstrated group differences, and then utilized to test for the influence of age, medication, age of onset, duration of illness, symptom severity, and intelligence.

RESULTS

Individuals with adolescent-onset psychosis exhibited pronounced FW and FAT abnormalities compared to HCs. FAT reductions were spatially more widespread in ADO-SCZ. FW increases, however, were only present in psychotic ADO-BPD. In HCs, but not in individuals with adolescent-onset psychosis, FAT was positively related to age.

CONCLUSIONS

We observe evidence for cellular (FAT) and extracellular (FW) white matter abnormalities in adolescent-onset psychosis. Although cellular white matter abnormalities were more prominent in ADO-SCZ, such alterations may reflect a shared trait, i.e. neurodevelopmental pathology, present across the psychosis spectrum. Extracellular abnormalities were evident in psychotic ADO-BPD, potentially indicating a more dynamic, state-dependent brain reaction to psychosis.

The co-occurrence of autistic spectrum disorder and schizophrenia: A nationwide population-based study

Although the co-occurrence of autistic spectrum disorder (ASD) and schizophrenia have been previously reported, the scope and magnitude of this comorbidity across large samples have not been sufficiently established. This study was aimed to assess the co-occurrence between schizophrenia and ASD in a large dataset, and to examine its predominance across different age and sex groups. Schizophrenia patients and age and sex frequency controls (n = 49,334) were assessed for the prevalence of autism spectrum disorder. The sample was stratified by age and sex, and co-occurrence was assessed using univariate and multivariate logistic regressions. Results indicated that schizophrenia was associated with ASD (OR = 7.01, 95%CI 2.98-16.43, p < .0001) across all age groups aside from 50 to 70 years. This association was significant among male participants (OR = 11.69, 95%CI 3.59-38.01, p < .0001) but not among female participants (OR = 2.33, 95%CI 0.60-9.03, p = .21). These findings indicate a large overlap between schizophrenia and ASD, and point to the need to expand the understanding of the potential mediating mechanisms of this co-occurrence.

Childhood schizotypal features vs. high-functioning autism spectrum disorder: Developmental overlaps and phenomenological differences

Although autism spectrum disorder and schizophrenia have allegedly different onset timelines (e.g. in early years of life vs adolescence/early adulthood), there is nonetheless a diagnostic grey-zone along developmental stages, in which overlapping clinical features related to social impairment and oddity could impact on the differential diagnosis between childhood schizotypal features and high-functioning autism spectrum disorder. A phenomenological perspective may be helpful for the purpose of timely differential diagnosis also in developmental years.

Two Sides of the Same Coin: A Case Report of First-Episode Catatonic Syndrome in a High-Functioning Autism Patient

Background: Catatonic phenomena such as stupor, mutism, stereotypy, echolalia, echopraxia, affective flattening, psychomotor deficits, and social withdrawal are characteristic symptoms of both schizophrenia and autism spectrum disorders (ASD), suggesting overlapping pathophysiological similarities such as altered glutamatergic and dopaminergic synaptic transmission and common genetic mutations. In daily clinical practice, ASD can be masked by manifest catatonic or psychotic symptoms and represent a diagnostic challenge, especially in patients with unknown or empty medical history. Unclear diagnosis is one of the main factors for delayed treatment. However, we are still missing diagnostic recommendations when dealing with ASD patients suffering from catatonic syndrome. Case presentation: A 31-year-old male patient without history of psychiatric disease presented with a severe catatonic syndrome and was admitted to our closed psychiatric ward. After the treatment with high-dose lorazepam and intramuscular olanzapine, catatonic symptoms largely remitted, but autistic traits persisted. Following a detailed anamnesis and a thorough neuropsychological testing, we diagnosed the patient with high-functioning autism and catatonic schizophrenia. The patient was discharged in a remitted state with long-acting injectable olanzapine. Conclusion: This case represents an example of diagnostic and therapeutic challenges of catatonic schizophrenia in high-functioning autism due to clinical and neurobiological overlaps of these conditions. We discuss clinical features together with pathophysiological concepts of both conditions. Furthermore, we tackle social and legal hurdles in Germany that naturally arise in these patients. Finally, we present diagnostic "red flags" that can be used to rationally select and conduct current recommended diagnostic assessments if there is a suspicion of ASD in patients with catatonic syndrome in order to provide them with the most appropriate treatment.

Comparison of prefrontal hemodynamic responses and cognitive deficits between adult patients with autism spectrum disorder and schizophrenia

Autism spectrum disorder (ASD) and schizophrenia share many phenotypic characteristics, but their association with prefrontal function have not been directly compared. The aim of this study is to compare cognitive profiles and their association with the prefrontal function between the two groups. We explored prefrontal dysfunction among adult individuals with ASD (n = 32), schizophrenia (n = 87), and healthy controls (HCs; n = 50). We assessed cognitive function in all participants using the Brief Assessment of Cognition in Schizophrenia (BACS). The BACS data of patients with schizophrenia were entered into hierarchical cluster analyses to assign subjects to a specific subgroup based on individual profiles. Using near-infrared spectroscopy, we measured hemodynamic responses in the fronto-temporal regions during a working memory task. Among the patients with schizophrenia, we defined 4 neurocognitive subgroups, including a global impairment, a mild impairment, and 2 selective impairment groups. Compared to the HCs, the ASD and schizophrenia groups had much weaker hemodynamic responses in the left DLPFC, left frontopolar cortex (FPC), and left inferior frontal gyrus. The ASD group showed a similar level of cognitive impairment with the mild level subgroup of schizophrenia. Additionally, the two groups shared reduced activity in the left DLPFC and left FPC during the task compared to HCs. Moreover, the BACS composite scores correlated positively with hemodynamic responses in a broad area involving fronto-temporal regions in the total patient sample. This research indicates considerable similarity in the left PFC dysfunction and its association with cognitive deficits between the disorders. These findings may guide future studies that investigate pathophysiological similarities between ASD and schizophrenia.

Autistic Symptoms in Schizophrenia Spectrum Disorders: A Systematic Review and Meta-Analysis

Background: Recent studies have examined the association between autism spectrum disorder and schizophrenia spectrum disorders, describing a number of cognitive features common to both conditions (e.g., weak central coherence, difficulties in set-shifting, impairment in theory of mind). Several studies have reported high levels of autistic symptoms in population with schizophrenia spectrum disorders. Our study systematically reviews and quantitatively synthetizes the current evidence on the presence of autistic symptoms in individuals with schizophrenia spectrum disorders. Methods: A comprehensive literature search of the PubMed/MEDLINE, Cochrane Library, CINHAL, and Embase databases was performed from the date of their inceptions until March 2018. The primary outcome measure was the Autism Spectrum Quotient (AQ). As secondary outcome measures, we analyzed the AQ subscales. Data were extracted and analyzed by using a conservative model and expressed by standardized mean difference (SMD). Results: Thirteen studies comprising a total of 1,958 individuals were included in the analysis. Results showed that individuals with schizophrenia spectrum disorders have higher levels of autistic symptoms compared to healthy controls [SMD: 1.39, 95% confidence interval (CI): 1.11 to 1.68] and lower levels of autistic symptoms compared to individuals with autism (SMD: -1.27, 95% CI: -1.77 to -0.76). Conclusions: Current findings support that individuals with schizophrenia spectrum disorders have higher autistic symptoms than healthy controls. Therefore, further studies are needed in order to shed light on the association between these two conditions.

Autistic traits in a sample of adult patients with schizophrenia: prevalence and correlates

BACKGROUND

Schizophrenia and autism spectrum disorder (ASD) are currently conceptualized as distinct disorders. However, the relationship between these two disorders has been revisited in recent years due to evidence that they share phenotypic and genotypic expressions. This study aimed to identify ASD traits in patients with schizophrenia, and to define their demographic, psychopathological, cognitive and functional correlates.

METHOD

Seventy-five schizophrenia patients (20 females, mean age 42 ± 12) were evaluated with the Autism Diagnostic Observation Schedule (ADOS) and the Autism Diagnostic Interview-Revised (ADI-R). Participants were also assessed with clinical, neuropsychological, and psychosocial functioning measures.

RESULTS

Of the 75 patients, 47 were negative to all the autism scales administered (ADOS-TOT-NEG), 21 patients were positive to the ADOS Language sub-domain (ADOS-L-POS), 21 patients were positive to the ADOS Reciprocal Social Interaction (RSI) sub-domain (ADOS-RSI-POS), 14 patients were positive to the ADOS Total scale (ADOS-TOT-POS), and nine patients were positive to the ADI-R scale (ADI-R-POS). Demographic (duration of illness), psychopathological (negative symptoms and general psychopathology), and cognitive (working memory and processing speed) differences emerged between schizophrenic patients with and without ASD traits, while no differences in psychosocial functioning were detected. Results of this study indicate the existence, in a sample of patients with a diagnosis of schizophrenia, of a distinct group of subjects with ASD features, characterized by specific symptomatological and cognitive profile.

CONCLUSIONS

These findings may contribute to better characterize patients with schizophrenia in order to develop new procedures and therapeutic tools in a more personalized perspective.

Asperger Syndrome and Schizophrenia: A Comparative Neuropsychological Study

There has been an increasing interest in possible connections between autism spectrum disorder (ASD) and schizophrenia in the last decade. Neuropsychological comparison studies have, however, been few. The present study examined similarities and differences in intellectual and executive functioning between adults with Asperger syndrome (AS) and adults with schizophrenic psychosis (SP). A group with AS and a group with SP were assessed neuropsychologically with WAIS-III and D-KEFS. Similarities were found between groups, as displayed by an uneven cognitive profile, limitations in working memory, processing speed and some aspects of executive functioning. Full Scale IQ was higher in the AS group. These results add to the current research illuminating similarities and differences between ASD and schizophrenia on a cognitive level.

What is the prevalence of autism spectrum disorder and ASD traits in psychosis? A systematic review

There is increasing evidence to suggest both a symptomatic overlap and a clinically significant degree of co-occurrence between Autism Spectrum Disorders (ASD) and psychotic disorders such as schizophrenia but the nature of such relationships remain unclear. We reviewed the literature reporting prevalence rates of Autistic-like Traits (ALTs) and ASD in populations with a diagnosis of schizophrenia or other psychotic disorder. A search of three large databases was conducted and from this seven studies met the criteria for inclusion. The point prevalence rates for ALTs ranged from 9.6% to 61%, whilst the prevalence rates for diagnosed ASD ranged from <1% to 52% across outpatient and inpatient populations. This suggests that prevalence rates of ALTs and ASD in psychosis populations are much higher than in the general population. This has important implications regarding future research, and clinical implications in terms of ensuring that patients receive the most appropriate diagnosis and treatment.

Treating Schizophrenia With the Diuretic Bumetanide: A Case Report

Administration of the diuretic and NKCC1 chloride cotransporter antagonist bumetanide reduces the severity of autism spectrum disorders in children, and this effect is mediated by a reduction of the elevated intracellular chloride concentrations and a reinforcement of GABAergic inhibition (Lemonnier et al Transl Psychiatry. 2012;2:e202; Tyzio et al Science. 2014;343:675-679). Here, we report that this treatment also reduces the severity of symptoms in an adolescent with schizophrenia. Long-term treatment reduced hallucinations significantly, suggesting that this treatment may also be useful to treat schizophrenia. Further clinical trials and experimental studies are warranted to test this hypothesis.

Lack of Gender-Related Differences in Childhood-Onset Schizophrenia

OBJECTIVE

Gender differences, including younger age of onset and greater premorbid deficits in men, have been reported in adult-onset schizophrenia. This study comprehensively evaluated gender differences in childhood-onset schizophrenia (COS), a rare variant of the disorder.

METHOD

Demographic, premorbid, clinical, familial, and cognitive characteristics, presence of chromosomal abnormalities, and brain magnetic resonance imaging cortical volumes were evaluated in 133 patients with COS. Cortical analyses included age- and gender-matched healthy volunteers (n = 124).

RESULTS

Males with COS (n = 72) had a slightly but significantly younger age of onset than females with COS (mean age 9.51 ± 2.28 versus 10.29 ± 1.63 years, t131 = 2.21, p = .03), higher verbal IQ scores (83.00 ± 15.97 versus 75.58 ± 15.10, t89 = 2.24, p = .03), and higher rates of comorbid pervasive developmental disorder (28.17% versus 6.90%, χ(2)1 = 9.54, p < .01) and attention-deficit/hyperactivity disorder (43.86% versus 21.43%, χ(2)1 = 5.40, p = .02). There were no significant gender differences across other demographic, IQ, or clinical measurements, frequency of chromosomal abnormalities, family clinical measurements, premorbid functioning, or in gender-by-disorder interactions for magnetic resonance imaging brain measurements.

CONCLUSION

The present comprehensive examination found few remarkable gender differences in COS. Although less striking than that seen in adult-onset schizophrenia, males with COS had a younger age of onset. Attention-deficit/hyperactivity disorder and pervasive developmental disorder rates were high in COS overall, suggesting greater neurodevelopmental vulnerability in COS. However, the gender ratios of these comorbidities in COS mirror those of the general populations, indicating that these gender differences might be unrelated to COS.

Clinical predictors of antipsychotic use in children and adolescents with autism spectrum disorders: a historical open cohort study using electronic health records

Children with autism spectrum disorders (ASD) are more likely to receive antipsychotics than any other psychopharmacological medication, yet the psychiatric disorders and symptoms associated with treatment are unclear. We aimed to determine the predictors of antipsychotic use in children with ASD receiving psychiatric care. The sample consisted of 3482 children aged 3-17 with an ICD-10 diagnosis of ASD referred to mental health services between 2008 and 2013. Antipsychotic use outcome, comorbid diagnoses, and other clinical covariates, including challenging behaviours were extracted from anonymised patient records. Of the 3482 children (79 % male) with ASD, 348 (10 %) received antipsychotic medication. The fully adjusted model indicated that comorbid diagnoses including hyperkinetic (OR 1.44, 95 %CI 1.01-2.06), psychotic (5.71, 3.3-10.6), depressive (2.36, 1.37-4.09), obsessive-compulsive (2.31, 1.16-4.61) and tic disorders (2.76, 1.09-6.95) were associated with antipsychotic use. In addition, clinician-rated levels of aggression, self-injurious behaviours, reduced adaptive function, and overall parental concern for their child's presenting symptoms were significant risk factors for later antipsychotic use. In ASD, a number of comorbid psychiatric disorders are independent predictors for antipsychotic treatment, even after adjustment for familial, socio-demographic and individual factors. As current trial evidence excludes children with comorbidity, more pragmatic randomised controlled trials with long-term drug monitoring are needed.

Autism beyond diagnostic categories: characterization of autistic phenotypes in schizophrenia

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.

METHODS

Specific items of the Positive and Negative Syndrome Scale were employed and summed up to form a dimensional autism severity score (PAUSS). The score was created in a schizophrenia sample (N = 1156) and validated in adult high-functioning autism spectrum disorder (ASD) patients (N = 165). To this end, the Autism Diagnostic Observation Schedule (ADOS), the Autism (AQ) and Empathy Quotient (EQ) self-rating questionnaires were applied back to back with the newly developed PAUSS.

RESULTS

PAUSS differentiated between ASD, schizophrenia and a disease-control sample and substantially correlated with the Autism Diagnostic Observation Schedule. Patients with ADOS scores ≥12 obtained highest, those with scores <7 lowest PAUSS values. AQ and EQ were not found to vary dependent on ADOS diagnosis. ROC curves for ADOS and PAUSS resulted in AuC values of 0.9 and 0.8, whereas AQ and EQ performed at chance level in the prediction of ASD.

CONCLUSIONS

This work underscores the convergence of schizophrenia negative symptoms and autistic phenotypes. PAUSS evolved as a measure capturing the continuous nature of autistic behaviors. The definition of extreme-groups based on the dimensional PAUSS may permit future investigations of genetic constellations modulating autistic phenotypes.

The association between autism and schizophrenia spectrum disorders: A review of eight alternate models of co-occurrence

Although now believed to be two distinct disorders, autism spectrum disorders (ASD) and schizophrenia spectrum disorders (SSD) share multiple phenotypic similarities and risk factors, and have been reported to co-occur at elevated rates. In this narrative review, we give a brief overview of the phenomenological, genetic, environmental, and imaging evidence for the overlap between ASD and SSD, highlighting similarities and areas of distinction. We examine eight possible alternate models of explanation for the association and comorbidity between the disorders, and set out a research agenda to test these models. Understanding how and why these disorders co-occur has important implications for diagnosis, treatment, and prognosis, as well as for developing fundamental aetiological models of the disorders.

Acute behavioral crises in psychiatric inpatients with autism spectrum disorder (ASD): recognition of concomitant medical or non-ASD psychiatric conditions predicts enhanced improvement

During adolescence, some individuals with autism spectrum disorder (ASD) engage in severe challenging behaviors, such as aggression, self-injury, disruption, agitation and tantrums. We aimed to assess risk factors associated with very acute behavioral crises in adolescents with ASD admitted to a dedicated neurobehavioral unit. We included retrospectively in 2008 and 2009 29 adolescents and young adults with ASD hospitalized for severe challenging behaviors and proposed a guideline (Perisse et al., 2010) that we applied prospectively for 29 patients recruited for the same indications between 2010 and 2012. In total, 58 patients were admitted (n=70 hospitalizations, mean age=15.66 (±4.07) years, 76% male). We systematically collected data describing socio-demographic characteristics, clinical variables (severity, presence of language, cognitive level), comorbid organic conditions, etiologic diagnosis of the episode, and treatments. We explored predictors of Global Assessment Functioning Scale (GAFS) score and duration of hospitalization at discharge. All but 2 patients exhibited severe autistic symptoms and intellectual disability (ID), and two-thirds had no functional verbal language. During the inpatient stay (mean=84.3 (±94.9) days), patients doubled on average their GAFS scores (mean=17.66 (±9.05) at admission vs. mean=31.4 (±9.48) at discharge). Most common etiologies for acute behavioral crises were organic causes [n=20 (28%), including epilepsy: n=10 (14%) and painful medical conditions: n=10 (14%)], environmental causes [n=17 (25%) including lack of treatment: n=11 (16%) and adjustment disorder: n=6 (9%)], and non-ASD psychiatric condition [n=33 (48%) including catatonia: n=5 (7%), major depressive episode: n=6 (9%), bipolar disorder: n=4 (6%), schizophrenia: n=6 (9%), other/unknown diagnosis: n=12 (17%)]. We found no influence of age, gender, socio-economic status, migration, level of ID, or history of seizure on improvement of GAFS score at discharge. Severity of autism at admission was the only negative predictor (p<.001). Painful medical conditions (p=.04), non-ASD psychiatric diagnoses (p=.001), prior usage of specialized ASD care programs (p=.004), functional language (p=.007), as well as a higher number of challenging behaviors upon admission (p=.001) were associated with higher GAFS scores at discharge. Clinical severity at admission, based on the number of challenging behaviors (r=.35, p=.003) and GAFS score (r=-.32, p=.008) was correlated with a longer inpatient stay. Longer hospitalization was however correlated (r=.27, p=.03) with higher GAFS score at discharge even after adjustment for confounding factors. Challenging behaviors among adolescents with ASD may stem from diverse risk factors, including environmental problems, comorbid acute psychiatric conditions, or somatic illness such as epilepsy or acute pain. The management of these behavioral challenges requires a unified, multidisciplinary approach.

Normal P50 Gating in Children with Autism, Yet Attenuated P50 Amplitude in the Asperger Subcategory

Autism spectrum disorders (ASD) and schizophrenia are separate disorders, but there is evidence of conversion or comorbid overlap. The objective of this paper was to explore whether deficits in sensory gating, as seen in some schizophrenia patients, can also be found in a group of ASD children compared to neurotypically developed children. An additional aim was to investigate the possibility of subdividing our ASD sample based on these gating deficits. In a case-control design, we assessed gating of the P50 and N100 amplitude in 31 ASD children and 39 healthy matched controls (8-12 years) and screened for differences between groups and within the ASD group. We did not find disturbances in auditory P50 and N100 filtering in the group of ASD children as a whole, nor did we find abnormal P50 and N100 amplitudes. However, the P50 amplitude to the conditioning stimulus was significantly reduced in the Asperger subgroup compared to healthy controls. In contrast to what is usually reported for patients with schizophrenia, we found no evidence for sensory gating deficits in our group of ASD children taken as a whole. However, reduced P50 amplitude to conditioning stimuli was found in the Asperger group, which is similar to what has been described in some studies in schizophrenia patients. There was a positive correlation between the P50 amplitude of the conditioning stimuli and anxiety score in the pervasive developmental disorder not otherwise specified group, which indicates a relation between anxiety and sensory registration in this group.

Factor Analysis Demonstrates a Common Schizoidal Phenotype within Autistic and Schizotypal Tendency: Implications for Neuroscientific Studies

Behavioral and cognitive dysfunction, particularly social and communication impairments, are shared between autism and schizophrenia spectrum disorders, while evidence for a diametric autism-positive schizophrenia symptom profile is inconsistent. We investigated the shared phenotype at a personality trait level, particularly its resemblance to schizoid personality disorder, as well as differential aspects of the autism-schizophrenia model. Items of the autism spectrum quotient (AQ) and schizotypal personality questionnaire (SPQ) were pseudo-randomly combined, and were completed by 449 (162 male, 287 female) non-clinical participants aged 18-40. A factor analysis revealed three factors; the first represented a shared social disorganization phenotype, the second reflected perceptual oddities specific to schizotypy while the third reflected social rigidity specific to autism. The AQ and SPQ were strongly correlated with Factor 1 (AQ: r = 0.75, p < 0.001; SPQ: r = 0.96, p < 0.001), SPQ score was correlated with Factor 2 (r = 0.51, p < 0.001), particularly in cognitive-perceptual features (r = 0.66, p < 0.001), and AQ score was strongly correlated with Factor 3 (r = 0.76, p < 0.001). Furthermore, there was no relationship between Factor 1 and Factor 2. Thus, there is robust evidence for a shared social disorganization phenotype in autistic and schizotypal tendency, which reflects the schizoid phenotype. Discriminating and independent dimensions of schizotypal and autistic tendency exist in Factors 2 and 3, respectively. Current diagnostic protocols could result in different diagnoses depending on the instrument used, suggesting the need for neuromarkers that objectively differentiate autistic and schizotypal traits and resolve the question of commonality versus co-morbidity.

Neurological abnormalities in recent-onset schizophrenia and asperger-syndrome

BACKGROUND

Neurological abnormalities including a variety of subtle deficits such as discrete impairments in sensory integration, motor coordination (MOCO), and sequencing of complex motor acts are frequently found in patients with schizophrenia (SZ) and commonly referred to as neurological soft signs (NSS). Asperger-syndrome (AS) is characterized by sensory-motor difficulties as well. However, the question whether the two disorders share a common or a disease-specific pattern of NSS remains unresolved.

METHOD

A total of 78 age- and education-matched participants [26 patients with recent-onset SZ, 26 individuals with AS, and 26 healthy controls (HC)] were recruited for the study. Analyses of covariance (ANCOVAs), with age, years of education, and medication included as covariates, were used to examine group differences on total NSS and the five subscale scores. Discriminant analyses were employed to identify the NSS subscales that maximally discriminate between the three groups.

RESULTS

Significant differences among the three groups were found in NSS total score and on the five NSS subscales. The clinical groups differed significantly in the NSS subscale MOCO. The correct discriminant rate between patients with SZ and individuals with AS was 61.5%. The correct discriminant rate was 92.3% between individuals with AS and HC, and 80.8% between SZ patients and HC, respectively.

CONCLUSION

Our findings provide new evidence for the presence of NSS in AS and lend further support to previously reported difficulties in movement control in this disorder. According to the present results, SZ and AS seem to be characterized by both quantitative and qualitative NSS expression.

Catatonic features in adolescents with schizophrenia with and without a comorbid pervasive developmental disorder

BACKGROUND

Catatonia has been associated with both schizophrenia and pervasive developmental disorders. The aim of this study was to evaluate catatonic features among adolescents suffering from schizophrenia. Further, we compared these features between adolescents with a comorbid pervasive developmental disorder and those without one. Finally, we wanted to compare the profile of catatonia-like features of our schizophrenia patients to that described earlier among persons with autism spectrum disorders.

METHODS

The study comprised a consecutive sample of 18 adolescents with schizophrenia (mean age 15.6 years, SD 1.4) and their families. Diagnosis of schizophrenia was assessed with the Schedule for Affective Disorders and Schizophrenia for School-Aged Children - Present and Life-Time (K-SADS-PL) for the DSM-IV. The Diagnostic Interview for Social and Communication Disorders version 11 was used to assess catatonic features.

RESULTS

All adolescents with schizophrenia had showed some lifetime catatonic features. Approximately 78% of them had already expressed these features before the age of 10. The number of catatonic features before the age of 10 was significantly higher among the adolescents with a comorbid pervasive developmental disorder compared to those without one. The numbers of catatonic features after the age of 10 did not significantly differ between the two groups. Over three-quarters of schizophrenia patients shared four lifetime catatonic features: "lacks facial expression", "odd intonation", "poor eye contact" and "lack of cooperation".

CONCLUSIONS

Adolescent schizophrenia patients with a comorbid pervasive developmental disorder show many catatonic features in childhood whereas those without one seem to develop these features first in adolescence. Catatonic features exhibited by adolescents with schizophrenia resemble those described among persons with pervasive developmental disorders without schizophrenia.