Schizophrenia spectrum and attention-deficit/hyperactivity disorder symptoms in autism spectrum disorder and controls

Risk of psychosis in autism spectrum disorder individuals exposed to psychosocial stressors: A 9-year chart review study

Psychosocial stressors have been suggested to precipitate psychotic episodes in patients with pre-existing psychosis and otherwise healthy subjects. However, such a risk has never been formally investigated in individuals with autism spectrum disorder (ASD). Sixty-nine autistic adolescents hospitalized for psychotic/manic symptoms (PSY) and other mental health issues (NPSY) over a 9-year period were compared with reference to their previous exposure to psychosocial stressors. ASD diagnoses satisfied the International Classification of Diseases (ICD)-10 criteria. Psychotic/manic symptom assessment followed the Kiddie Schedule for Affective Disorders and Schizophrenia (K-SADS). Psychosocial stressor exposure was collected separately at each admission. Preliminarily, univariate between-group comparisons were conducted. Then, a binomial model was adopted to investigate associations with previous exposure to psychosocial stressors. Results were reported with a change in AIC (ΔAIC). PSY patients presented with higher previous exposure to adverse life events (30.43% vs. 6.52%, OR = 6.079 [1.209, 40.926], p = 0.013) and school/work difficulties (30.43% vs. 8.70%, OR = 4.478 [0.984, 23.846], p = 0.034) than NPSY ones. Admissions for psychotic/manic symptoms occurred more likely in the context of family disturbances (OR = 2.275 [1.045, 5.045], p = 0.030) and adverse life events (OR = 3.489 [1.194, 11.161], p = 0.014). The fitted binomial model was found to be significant compared to the random effects model (ΔAIC = -1.962; χ2 10  = 21.96, p = 0.015), with the risk of presenting psychotic/manic symptoms being increased by family disturbances (z = +4.118) and school/work difficulties (z = +2.455). The results suggest a potential psychosis-inducing effect of psychosocial stressors in ASD, which has clinical and policy implications.

Neurodevelopmental Disorders, Schizophrenia Spectrum Disorders and Catatonia: The "Iron Triangle" Rediscovered in a Case Report

Catatonia is a complex neuropsychiatric syndrome, occurring in the context of different psychiatric and neurodevelopmental disorders, in neurological and medical disorders, and after substance abuse or withdrawal. The relationship between Autism Spectrum Disorder (ASD), Schizophrenia Spectrum Disorders (SSDs) and catatonia has been previously discussed, with the three disorders interpreted as different manifestations of the same underlying brain disorder (the "Iron Triangle"). We discuss in this paper the diagnostic, clinical and therapeutic implications of this complex relationship in an adolescent with ASD, who presented an acute psychotic onset with catatonia, associated with mixed mood symptoms. Second-generation antipsychotics were used to manage psychotic, behavioral and affective symptoms, with worsening of the catatonic symptoms. In this clinical condition, antipsychotics may be useful at the lowest dosages, with increases only in the acute phases, especially when benzodiazepines are ineffective. Mood stabilizers with higher GABAergic effects (such as Valproate and Gabapentin) and Lithium salts may be more useful and well tolerated, given the frequent association of depressive and manic symptoms with mixed features.

Diagnostic progression to schizophrenia: A nationwide cohort study of 11 170 adolescents and young adults with autism spectrum disorder

AIMS

Previous studies have suggested an increased risk of developing schizophrenia later in life in children with autism spectrum disorder (ASD). This study aims to investigate the diagnosis stability and the potential predictors for progression to schizophrenia in ASD.

METHODS

We recruited 11 170 adolescents (10-19 years) and young adults (20-29 years) with ASD between 2001 and 2010. They were followed up to the end of 2011 to identify newly diagnosed schizophrenia. The Kaplan-Meier method and Cox regression with age as a time scale were employed to estimate incidence rates and the significance of candidate predictors.

RESULTS

The progression rate from ASD to schizophrenia was 10.26% for 10 years of follow-up. Among 860 progressors, 580 (67.44%) occurred within the first 3 years after a diagnosis of ASD. The identified predictors were age (reported as hazard ratio with 95% confidence interval: 1.13; 1.11-1.15), depressive disorder (1.36; 1.09-1.69), alcohol use disorder (3.05; 2.14-4.35), substance use disorder (1.91; 1.18-3.09), cluster A personality disorder (2.95; 1.79-4.84), cluster B personality disorder (1.86; 1.05-3.28), and a family history of schizophrenia (2.12; 1.65-2.74).

CONCLUSION

More than two-thirds of the progressors developed schizophrenia within the first 3 years. Demographic characteristics, physical and psychiatric comorbidities, and psychiatric family history were significant predictors of progression.

Autism Spectrum Disorder and Clinical High Risk for Psychosis: A Systematic Review and Meta-analysis

Psychotic experiences can occur in autism spectrum disorders (ASD). Some of the ASD individuals with these experiences may fulfil Clinical High-Risk for Psychosis (CHR-P) criteria. A systematic literature search was performed to review the information on ASD and CHR-P. A meta-analysis of the proportion of CHR-P in ASD was conducted. The systematic review included 13 studies. The mean age of ASD individuals across the included studies was 11.09 years. The Attenuated Psychosis Syndrome subgroup was the most frequently reported. Four studies were meta-analysed, showing that 11.6% of CHR-P individuals have an ASD diagnosis. Symptoms of prodromal psychosis may be present in individuals with ASD. The transition from CHR-P to psychosis is not affected by ASD.

A Neurodevelopment Approach for a Transitional Model of Early Onset Schizophrenia

In the last decades, the conceptualization of schizophrenia has dramatically changed, moving from a neurodegenerative process occurring in early adult life to a neurodevelopmental disorder starting be-fore birth, showing a variety of premorbid and prodromal symptoms and, in relatively few cases, evolving in the full-blown psychotic syndrome. High rates of co-occurring different neurodevelopmental disorders such as Autism spectrum disorder and ADHD, predating the onset of SCZ, and neurobio-logical underpinning with significant similarities, support the notion of a pan-developmental disturbance consisting of impairments in neuromotor, receptive language, social and cognitive development. Con-sidering that many SCZ risk factors may be similar to symptoms of other neurodevelopmental psychi-atric disorders, transition processes from child & adolescent to adult systems of care should include both high risk people as well as subject with other neurodevelopmental psychiatric disorders with different levels of severity. This descriptive mini-review discuss the need of innovative clinical approaches, re-considering specific diagnostic categories, stimulating a careful analysis of risk factors and promoting the appropriate use of new and safer medications.

Categorical and Dimensional Approaches to Examining the Joint Effect of Autism and Schizotypal Personality Disorder on Sustained Attention

INTRODUCTION

Accumulating evidence for the co-occurrence autism spectrum disorder (ASD) and schizotypal personality disorder (SPD) at both the diagnostic and symptom levels raises important questions about the nature of their association and the effect of their co-occurrence on the individual's phenotype and functional outcome. Research comparing adults with ASD and SPD, as well as the impact of their co-occurrence on outcomes is extremely limited. We investigated executive functioning in terms of response inhibition and sustained attention, candidate endophenotypes of both conditions, in adults with ASD, SPD, comorbid ASD and SPD, and neurotypical adults using both categorical and dimensional approaches.

METHODS

A total of 88 adults (Mean Age = 37.54; SD = 10.17): ASD (n = 26; M/F = 20/6); SPD (n = 20; M/F = 14/6); comorbid ASD and SPD (n=9; M/F=6/3) and neurotypicals (n=33; M/F=23/10) completed the Sustained Attention to Response Task (SART) in both its fixed and random forms. Positive and autistic symptom severity was assessed with the positive subscale of the Positive and Negative Syndrome Scale (PANSSpos) and the PANSS Autism Severity Score (PAUSS), respectively.

RESULTS

Controlling for full scale IQ, working memory and medication dosage, group analyses revealed that the comorbid group committed fewer omission errors than the ASD group on the fixed SART, and fewer omission errors than the ASD and SPD groups on the random SART. The individual difference analyses of the entire sample revealed that the PANSSpos and PAUSS interactively reduced omission errors in both the fixed and random SARTs, as well as increased d' scores, indicative of improved overall performance. We observed no significant results for commission errors or reaction time.

CONCLUSIONS

Concurrent elevated levels of autistic and positive psychotic symptoms seem to be associated with improved sustained attention abilities (reduced omission errors) but not inhibition (commission errors). Our findings highlight the importance of investigating the concurrent effect of ASD and SPD at both the symptom and diagnostic levels, and raise important questions for future research regarding the clinical and behavioral phenotypes of adults with dual diagnosis and, more generally, about the nature of the relationship between ASD and SPD.

Revisiting the overlap between autistic and schizotypal traits in the non-clinical population using meta-analysis and network analysis

The present study aimed to explore the relationship between autistic and schizotypal traits in the non-clinical population. We first conducted a meta-analysis to quantify the correlation between self-reported autistic traits and the three dimensions of schizotypal traits (positive, negative and disorganization). The strongest correlation was found between autistic traits and negative schizotypal traits (r = 0.536, 95% CI [0.481, 0.586]), followed by the disorganization (r = 0.355, 95% CI [0.304, 0.404]) and positive (r = 0.256, 95% CI [0.208, 0.302]) dimensions. To visualize the partial correlations between dimensional behavioural traits, we constructed a network model based on a large sample of college students (N = 2469). Negative schizotypal traits were strongly correlated with autistic social/communicative deficits, whereas positive schizotypal traits were inversely correlated with autistic-like traits, lending support to the psychosis-autism diametrical model. Disentangling the overlapping and diametrical structure of autism and schizophrenia may help to elucidate the aetiology of these two neurodevelopmental disorders.

Clinical Profiles and Conversion Rates Among Young Individuals With Autism Spectrum Disorder Who Present to Clinical High Risk for Psychosis Services

OBJECTIVE

The overlap versus independence of autism spectrum disorder (ASD) and schizophrenia is a topic that has garnered the attention of generations of clinicians and scientists. Although high rates of psychotic symptoms have been identified in individuals with ASD, the nature, prevalence, and prognostic significance of subclinical psychotic experiences in ASD remain poorly understood.

METHOD

This study sought to compare baseline characteristics, clinical profiles, and conversion outcomes between young individuals at clinical high risk for psychosis (CHR) who presented with or without a prior ASD diagnosis during the second phase of the North American Prodrome Longitudinal Study (NAPLS, N = 764).

RESULTS

Patients with CHR and ASD (CHR/ASD+, n = 26) tended to exhibit greater social and social cognitive difficulties, but expressed relatively levels of core psychosis symptoms similar to those of to patients with CHR but no ASD (CHR/ASD-). Risk for conversion to co-occurring psychosis (18.2% CHR/ASD+ versus 16.8% CHR/ASD-) was equivalent between CHR/ASD+ and CHR/ASD- groups, and the NAPLS2 Psychosis Risk Calculator predicted conversion to psychosis equally well across groups.

CONCLUSION

These results suggest that baseline psychosis symptoms, predictors of risk for conversion, and ultimate conversion rates are similar in patients with CHR with and without ASD. They further suggest that ASD must not be considered a mutually exclusive diagnosis when such youth present in CHR settings. Future research is needed to better track trajectories in larger cohorts of individuals with CHR and comorbid ASD and to understand whether treatment recommendations effective in the broader CHR population are useful for this particular population as well.

Co-occurring psychiatric conditions in autism spectrum disorder

Individuals with autism spectrum disorder (ASD) are at increased risk for experiencing one or more co-occurring psychiatric conditions. When present, these conditions are associated with additional impairment and distress. It is therefore crucial that clinicians and researchers adequately understand and address these challenges. However, due to symptom overlap, diagnostic overshadowing, and ambiguous symptom presentation in ASD, the assessment of co-occurring conditions in ASD is complex and challenging. Likewise, individual difference factors, such as age, intellectual functioning, and gender, may influence the presentation of co-occurring symptoms. Relatedly, a transdiagnostic framework may offer utility in assessing and treating co-occurring conditions. However, with the exception of anxiety disorders, treatment research for co-occurring psychiatric conditions in ASD is relatively limited. Therefore, the present paper aims to summarize and review available research on the most common co-occurring psychiatric disorders in ASD, with a focus on estimated population-based prevalence rates, diagnostic challenges, the influence of individual differences, and assessment guidelines. The utility of a transdiagnostic framework for conceptualizing co-occurring disorders in ASD is discussed, and the state of treatment research for co-occurring disorders is summarized. This study concludes with a summary of the extant literature, as well as recommendations for future research.

Diagnostic Accuracy of the CASI-4R Psychosis Subscale for Children Evaluated in Pediatric Outpatient Clinics

Diagnostic accuracy of the Diagnostic and Statistical Manual of Mental Disorders-oriented Child and Adolescent Symptom Inventory (CASI-4R) Psychotic Symptoms scale was tested using receiver operating characteristic analyses to identify clinically significant psychotic symptoms. Participants were new outpatients (N = 700), ages 6.0 to 12.9 years (M = 9.7, SD = 1.8) at 9 child outpatient mental health clinics, who participated in the Longitudinal Assessment of Manic Symptoms (LAMS) Study baseline assessment. Because LAMS undersampled participants with low mania scores by design, present analyses weighted low scorers to produce unbiased estimates. Psychotic symptoms, operationally defined as a score of 3 or more for hallucinations or 4 or more for delusions based on the Schedule for Affective Disorders and Schizophrenia (K-SADS) psychosis items, occurred in 7% of youth. K-SADS diagnoses for those identified with psychotic symptoms above threshold included major depressive disorder, bipolar spectrum disorder, attention deficit/hyperactivity disorder, posttraumatic stress disorder, psychotic disorders, and autism spectrum disorder. The optimal psychosis screening cut score (maximizing sensitivity and specificity) was 2.75+ (corresponding diagnostic likelihood ratio [DiLR] = 4.29) for the parent version and 3.50+ (DiLR = 5.67) for the teacher version. The Area under the Curve for parent and teacher report was .83 and .74 (both p < .001). Parent report performed significantly better than teacher report for identifying psychotic symptoms above threshold (p = .03). The CASI-4R Psychosis subscale (J) appears clinically useful for identifying psychotic symptoms in children because of its brevity and accuracy.

Attentional set-shifting and social abilities in children with schizotypal and comorbid autism spectrum disorders

OBJECTIVE

While diagnostically independent, autism and schizotypal disorders can co-occur. Their concurrent impact on outcomes and phenotypes has not been investigated. We investigated the impact of comorbid autism and schizotypal disorders in children on executive functioning and socio-pragmatic skills - core features of both disorders.

METHOD

Executive functioning (assessed with the Cambridge Neuropsychological Test Automated Battery) and socio-pragmatic skills (assessed using the Melbourne Assessment of Schizotypy in Kids) were investigated in a total of 67 (6-12 year old) children with autism ( n = 15; M/F = 10/5), schizotypal disorder ( n = 8; M/F = 5/3) and comorbid autism and schizotypal disorder ( n = 12; M/F = 5/7) and typically developing children ( n = 32; M/F = 17/15).

RESULTS

Both the autism and schizotypal disorder groups performed more poorly than the typically developing group on socio-pragmatic skills and overall performance (i.e. number of stages completed) of the intra-/extra-dimensional set-shifting task (all ps < 0.001). Clear distinctions between the autism and schizotypal groups were present in the intra-/extra-dimensional task relative to the typically developing group - the autism group had difficulties with extra-dimensional shifts ( p < 0.001), and the schizotypal disorder group with intra-dimensional shifts ( p = 0.08). Interestingly, the overall performance of the comorbid group on the intra-/extra-dimensional task was not significantly different from the typically developing group, and they were superior to both the autism ( p = 0.019) and schizotypal disorder ( p = 0.042) groups on socio-pragmatic skills.

CONCLUSION

The phenotypical overlap between autism and schizotypal disorders may be precipitated by different cognitive styles and/or mechanisms associated with attention and information processing. We propose that sustaining and switching attention represent two poles of irregularities across the autism and schizotypal spectra, which appear to converge in a compensatory manner in the comorbid group. Our findings highlight the importance of investigating children with a dual diagnosis of autism and schizotypal disorders, and raise intriguing questions about possible mechanisms to explain the attenuated impairment observed in the group of children with comorbid autism and schizotpyal disorders.

Parent-Reported Developmental Regression in Autism: Epilepsy, IQ, Schizophrenia Spectrum Symptoms, and Special Education

Examined the psychiatric and clinical correlates of loss of previously acquired skills (regression) as reported by parents of youth with autism spectrum disorder (ASD). Study sample comprised 6- to 18-year old (N = 213) children and adolescents with ASD. Parents reported regression in 77 (36%) youth. A more homogeneous subgroup with regression between 18 and 36 months (n = 48) had higher rates of intellectual disability, epilepsy, and special education, more socially restrictive educational settings, and more severe ASD communication deficits and schizophrenia spectrum symptoms than non-regressed youth (n = 136). Similar results were obtained for a more inclusive definition of regression (n = 77). A brief parent report of developmental regression may be a useful clinical indicator of later general functioning.

Informant discrepancy defines discrete, clinically useful autism spectrum disorder subgroups

BACKGROUND

Discrepancy between informants (parents and teachers) in severity ratings of core symptoms commonly arise when assessing autism spectrum disorder (ASD). Whether such discrepancy yields unique information about the ASD phenotype and its clinical correlates has not been examined. We examined whether degree of discrepancy between parent and teacher ASD symptom ratings defines discrete, clinically meaningful subgroups of youth with ASD using an efficient, cost-effective procedure.

METHODS

Children with ASD (N = 283; 82% boys; M_age  = 10.5 years) were drawn from a specialty ASD clinic. Parents and teachers provided ratings of the three core DSM-IV-TR domains of ASD symptoms (communication, social, and perseverative behavior) with the Child and Adolescent Symptom Inventory-4R (CASI-4R). External validators included child psychotropic medication status, frequency of ASD-relevant school-based services, and the Autism Diagnostic Observation Schedule (ADOS-2).

RESULTS

Four distinct subgroups emerged that ranged from large between-informant discrepancy (informant-specific) to relative lack of discrepancy (i.e. informant agreement; cross-situational): Moderate Parent/Low Teacher or Low Parent/Moderate Teacher Severity (Discrepancy), and Moderate or High Symptom Severity (Agreement). Subgroups were highly distinct (mean probability of group assignment = 94%). Relative to Discrepancy subgroups, Agreement subgroups were more likely to receive psychotropic medication, school-based special education services, and an ADOS-2 diagnosis. These differential associations would not have been identified based solely on CASI-4R scores from one informant.

CONCLUSIONS

The degree of parent-teacher discrepancy about ASD symptom severity appears to provide more clinically useful information than reliance on a specific symptom domain or informant, and thus yields an innovative, cost-effective approach to assessing functional impairment. This conclusion stands in contrast to existing symptom clustering approaches in ASD, which treat within-informant patterns of symptom severity as generalizable across settings. Within-child variability in symptom expression across settings may yield uniquely useful information for characterizing the ASD phenotype.

Associations of attention-deficit/hyperactivity and other childhood disorders with psychotic experiences and disorders in adolescence

Prodromal symptoms of psychosis are associated with an increased risk of transition, functional impairment, poor mental health, and unfavorable developmental prospects. Existing interventions targeting the prodrome are non-satisfactory. It may thus be more promising to attempt to identify risk factors in the premorbid phase preceding the prodrome to increase the chances of successful preventive approaches. Here, we investigate whether childhood mental disorders in general and attention-deficit/hyperactivity disorder (ADHD) specifically indicate a risk for subsequent psychotic experiences and disorders. We used a sample from the prospective Avon Longitudinal Study of Parents and Children (N = 5528). When the participants were 7 years old, mental disorders were assigned according to the DSM-IV. In standardized interviews, psychotic experiences were assessed at age 12 and psychotic disorders at age 18. We examined the associations of each of the childhood mental disorders alone and in combination with psychotic experiences at age 12 and psychotic disorders at age 18 using logistic regression. Compared to participants without a disorder, participants with a mental disorder had a higher risk of psychotic experiences at age 12 (OR 1.70, 95 % CI 1.28-2.27) and of psychotic disorders at age 18 (OR 2.31, 95 % CI 1.03-5.15). Particularly, the ADHD combined subtype at age 7 was strongly associated with psychotic experiences at age 12 (OR 3.26, 95 % CI 1.74-6.10). As expected, childhood mental disorders are risk indicators of psychotic experiences and disorders. To improve prevention, health care professionals need to screen for psychotic experiences in children with non-psychotic disorders.

Clinical Correlates of Co-occurring Psychiatric and Autism Spectrum Disorder (ASD) Symptom-Induced Impairment in Children with ASD

Although psychiatric symptom severity and impairment are overlapping but nevertheless distinct illness parameters, little research has examined whether variables found to be associated with the severity are also correlated with symptom-induced impairment. Parents and teachers completed ratings of symptom-induced impairment for DSM-IV-referenced syndromes, and parents completed a background questionnaire for a consecutively referred sample of primarily male (81%) 6-to-12 year olds with autism spectrum disorder (ASD) (N = 221). Some clinical correlates (e.g., IQ < 70, maternal level of education, pregnancy complications, current use of psychotropic medication, season of birth) were associated with impairment for several disorders, whereas others were correlated with only a few syndromes (e.g., gender, co-morbid medical conditions) or were not related to impairment in any disorder (e.g., family psychopathology). There was little convergence in findings for parents' versus teachers' ratings. Some clinical correlates (e.g., season of birth, current psychotropic medication, maternal education) were unique predictors of three or more disorders. Pregnancy complications were uniquely associated with social anxiety and schizoid personality symptom-induced impairment. IQ was a unique predictor of schizophrenia, ASD, oppositional defiant disorder symptom-induced impairment. Children whose mothers had relatively fewer years of education had greater odds for symptom-induced impairment in social anxiety, depression, aggression, and mania and greater number of impairing conditions. Season of birth was the most robust correlate of symptom-induced impairment as rated by teachers but not by parents. Children born in fall evidenced higher rates of co-occurring psychiatric and ASD symptom-induced impairment and total number of impairing conditions. Many variables previously linked with symptom severity are also correlated with impairment.

Can Bayesian Theories of Autism Spectrum Disorder Help Improve Clinical Practice?

Diagnosis and individualized treatment of autism spectrum disorder (ASD) represent major problems for contemporary psychiatry. Tackling these problems requires guidance by a pathophysiological theory. In this paper, we consider recent theories that re-conceptualize ASD from a "Bayesian brain" perspective, which posit that the core abnormality of ASD resides in perceptual aberrations due to a disbalance in the precision of prediction errors (sensory noise) relative to the precision of predictions (prior beliefs). This results in percepts that are dominated by sensory inputs and less guided by top-down regularization and shifts the perceptual focus to detailed aspects of the environment with difficulties in extracting meaning. While these Bayesian theories have inspired ongoing empirical studies, their clinical implications have not yet been carved out. Here, we consider how this Bayesian perspective on disease mechanisms in ASD might contribute to improving clinical care for affected individuals. Specifically, we describe a computational strategy, based on generative (e.g., hierarchical Bayesian) models of behavioral and functional neuroimaging data, for establishing diagnostic tests. These tests could provide estimates of specific cognitive processes underlying ASD and delineate pathophysiological mechanisms with concrete treatment targets. Written with a clinical audience in mind, this article outlines how the development of computational diagnostics applicable to behavioral and functional neuroimaging data in routine clinical practice could not only fundamentally alter our concept of ASD but eventually also transform the clinical management of this disorder.

Trajectories and correlates of special education supports for youth with autism spectrum disorder and psychiatric comparisons

Relatively little is known about patterns of school-based supportive services for youth with autism spectrum disorder. This study describes these supportive services and their correlates, both cross-sectionally and retrospectively, in a large sample ( N = 283) of 6- to 18- year-old youth. To assess whether special education designation and classroom placement patterns were peculiar to autism spectrum disorder, we also conducted analyses comparing youth with autism spectrum disorder to those with other psychiatric diagnoses ( N = 1088). In higher grades, the relative quantity of three common supportive services received by youth with autism spectrum disorder decreased, while total supportive service quantity remained stable over time. Youth with autism spectrum disorder were more likely to receive a special education designation and were placed in less inclusive classroom settings than youth with other psychiatric diagnoses. These findings suggest that as youth with autism spectrum disorder reach higher grades, changes in service provision occur in terms of both time and quantity.

Comorbidity of intellectual disability confounds ascertainment of autism: implications for genetic diagnosis

While recent studies suggest a converging role for genetic factors towards risk for nosologically distinct disorders including autism, intellectual disability (ID), and epilepsy, current estimates of autism prevalence fail to take into account the impact of comorbidity of these disorders on autism diagnosis. We aimed to assess the effect of comorbidity on the diagnosis and prevalence of autism by analyzing 11 years (2000-2010) of special education enrollment data on approximately 6.2 million children per year. We found a 331% increase in the prevalence of autism from 2000 to 2010 within special education, potentially due to a diagnostic recategorization from frequently comorbid features such as ID. The decrease in ID prevalence equaled an average of 64.2% of the increase of autism prevalence for children aged 3-18 years. The proportion of ID cases potentially undergoing recategorization to autism was higher (P = 0.007) among older children (75%) than younger children (48%). Some US states showed significant negative correlations between the prevalence of autism compared to that of ID while others did not, suggesting state-specific health policy to be a major factor in categorizing autism. Further, a high frequency of autistic features was observed when individuals with classically defined genetic syndromes were evaluated for autism using standardized instruments. Our results suggest that current ascertainment practices are based on a single facet of autism-specific clinical features and do not consider associated comorbidities that may confound diagnosis. Longitudinal studies with detailed phenotyping and deep molecular genetic analyses are necessary to completely understand the cause of this complex disorder.

A longitudinal twin study of the association between childhood autistic traits and psychotic experiences in adolescence

Background

This twin study investigated whether autistic traits during childhood were associated with adolescent psychotic experiences.

Methods

Data were collected from a community sample of approximately 5000 twin pairs, which included 32 individuals with diagnosed autism spectrum conditions (ASC). Parents rated autistic traits in the twins at four points between ages 8–16 years. Positive, negative, and cognitive psychotic experiences were assessed at age 16 years using self- and parent-report scales. Longitudinal twin analyses tested the associations between these measures.

Results

Autistic traits correlated weakly or nonsignificantly with positive psychotic experiences (paranoia, hallucinations, and grandiosity), and modestly with cognitive psychotic experiences (cognitive disorganisation). Higher correlations were observed for parent-rated negative symptoms and self-reported anhedonia, although the proportion of variance in both accounted for by autistic traits was low (10 and 31 %, respectively). The majority of the genetic influences on negative symptoms and anhedonia were independent of autistic traits. Additionally, individuals with ASC displayed significantly more negative symptoms, anhedonia, and cognitive disorganisation than controls.

Conclusions

Autistic traits do not appear to be strongly associated with psychotic experiences in adolescence; associations were also largely restricted to negative symptoms. Of note, the degree to which the genetic and environmental causes of autistic traits influenced psychotic experiences was limited. These findings thus support a phenotypic and etiological distinction between autistic traits and psychotic experiences.

Electronic supplementary material

The online version of this article (doi:10.1186/s13229-015-0037-9) contains supplementary material, which is available to authorized users.

Are Negative Symptoms Dimensional or Categorical? Detection and Validation of Deficit Schizophrenia With Taxometric and Latent Variable Mixture Models

Studies have supported the validity of the deficit form of schizophrenia (ie, people with primary and enduring negative symptoms). A test of whether that group is a true taxon-that is, a distinct, discontinuous group-has yet to be conducted and the underlying structure of negative symptoms as categorical or dimensional remains undetermined. The present study examined the latent structure of negative and deficit symptoms to determine if a nonarbitrary boundary distinguishes deficit from nondeficit forms of schizophrenia (ie, whether these symptoms reflect a continuous or categorical variable). Schedule for the Deficit Syndrome ratings of 789 individuals with a psychotic disorder were submitted to taxometric and latent variable mixture analyses to test categorical vs dimensional hypotheses of negative symptoms and deficit schizophrenia. Analytic models favored a taxonic structure of negative symptoms and the validity of the deficit/nondeficit classification scheme. Taxometric classification outperformed clinician-based deficit/nondeficit classification in its association with summer birth, male sex, premorbid adjustment, neurocognition, and psychosocial functioning. Within taxon and complement classes, severity scores remained significant predictors of premorbid adjustment, neurocognition, and psychosocial functioning. Thus, although a categorical approach is validated, a hybrid categorical-dimensional conceptualization of negative symptoms also has validity for the prediction of external variables.

IRBIT regulates CaMKIIα activity and contributes to catecholamine homeostasis through tyrosine hydroxylase phosphorylation

Inositol 1,4,5-trisphosphate receptor (IP3R) binding protein released with IP3 (IRBIT) contributes to various physiological events (electrolyte transport and fluid secretion, mRNA polyadenylation, and the maintenance of genomic integrity) through its interaction with multiple targets. However, little is known about the physiological role of IRBIT in the brain. Here we identified calcium calmodulin-dependent kinase II alpha (CaMKIIα) as an IRBIT-interacting molecule in the central nervous system. IRBIT binds to and suppresses CaMKIIα kinase activity by inhibiting the binding of calmodulin to CaMKIIα. In addition, we show that mice lacking IRBIT present with elevated catecholamine levels, increased locomotor activity, and social abnormalities. The level of tyrosine hydroxylase (TH) phosphorylation by CaMKIIα, which affects TH activity, was significantly increased in the ventral tegmental area of IRBIT-deficient mice. We concluded that IRBIT suppresses CaMKIIα activity and contributes to catecholamine homeostasis through TH phosphorylation.

Comorbid anxiety and social avoidance in treatment of severe childhood aggression: response to adding risperidone to stimulant and parent training; mediation of disruptive symptom response

OBJECTIVE

In the four-site Treatment of Severe Childhood Aggression (TOSCA) study, addition of risperidone to stimulant and parent training moderately improved parent-rated disruptive behavior disorder (DBD) symptoms. This secondary study explores outcomes other than DBD and attention-deficit/hyperactivity disorder (ADHD) as measured by the Child and Adolescent Symptom Inventory-4R (CASI-4R).

METHODS

A total of 168 children ages 6-12 with severe aggression (physical harm), DBD, and ADHD were randomized to parent training plus stimulant plus placebo (basic treatment) or parent training plus stimulant plus risperidone (augmented treatment) for 9 weeks. All received only parent training plus stimulant for the first 3 weeks, then those with room for improvement received a second drug (placebo or risperidone) for 6 weeks. CASI-4R category item means at baseline and week 9 were entered into linear mixed-effects models for repeated measures to evaluate group differences in changes. Mediation of the primary DBD outcome was explored.

RESULTS

Parent ratings were nonsignificant with small/negligible effects, but teacher ratings (n=46 with complete data) showed significant augmented treatment advantage for symptoms of anxiety (p=0.013, d=0.71), schizophrenia spectrum (p=0.017, d=0.45), and impairment in these domains (p=0.02, d=0.26), all remaining significant after false discovery rate correction for multiple tests. Improvement in teacher-rated anxiety significantly (p=0.001) mediated the effect of risperidone augmentation on the primary outcome, the Disruptive-total of the parent-rated Nisonger Child Behavior Rating Form.

CONCLUSIONS

Addition of risperidone to parent training plus stimulant improves not only parent-rated DBD as previously reported, but also teacher-rated anxiety-social avoidance. Improvement in anxiety mediates improvement in DBD, suggesting anxiety-driven fight-or-flight disruptive behavior with aggression, with implications for potential treatment strategies. Clinicians should attend to possible anxiety in children presenting with aggression and DBD.

CLINICAL TRIAL REGISTRY

Treatment of Severe Childhood Aggression (The TOSCA Study). NCT00796302. clinicaltrials.gov.

Formal thought disorder in autism spectrum disorder predicts future symptom severity, but not psychosis prodrome

Formal thought disorder (FTD) is a disruption in the flow of thought, which is inferred from disorganisation of spoken language. FTD in autism spectrum disorders (ASD) might be a precursor of psychotic disorders or a manifestation of ASD symptom severity. The current longitudinal study is a seven-year follow-up of 91 individuals aged 5-12 years with ASD. We tested (1) whether childhood FTD predicted prodromal symptoms of psychosis in adolescence and (2) whether childhood FTD was associated with greater ASD symptom severity in adolescence. ASD symptom severity was assessed in childhood (T1) and 7 years later (T2), using the autism diagnostic observation schedule (ADOS). At T1, the Kiddie-Formal Thought Disorder Rating Scale (KFTDS) was used to measure symptoms of FTD. At T2, the prodromal questionnaire (PQ) was used to assess prodromal symptoms of psychosis. FTD at T1 did not predict prodromal symptoms of psychosis at T2 in children with ASD. FTD symptoms at T1, namely illogical thinking, predicted ASD symptom severity at T2 and this effect remained significant after controlling for T1 ASD symptom severity. In children with ASD, illogical thinking predicts severity of ASD symptoms in adolescence, but FTD does not predict prodromal symptoms of psychosis.

Depression and mood disorders among persons with autism spectrum disorders

In the past decade, Autism Spectrum Disorders (ASD) have both risen in prevalence and become a critical area of research in the field of developmental disabilities. As the body of knowledge about ASD has grown, the overlap of ASD with other problems has also become a rapidly emerging area of study. One of the most studied of these topics is comorbid psychopathology, with depression and mood disorders emerging as one of the more troublesome of these co-occurring conditions. A great deal of research is still needed to determine how best to assess and treat these disorders within the context of ASD. This manuscript reviews current trends and topics relative to this area of study.

Relation of symptom-induced impairment with other illness parameters in clinic-referred youth

OBJECTIVE

To examine the relation of caregiver ratings of psychiatric symptom-induced impairment with number and severity of symptoms and informant agreement in consecutive child psychiatry outpatient referrals.

METHODS

Parents and teachers completed a broadband DSM-IV-referenced rating scale with disorder-specific impairment for 636 youth (6-18 years). Illness parameters included impairment, number and severity of symptoms, and their combination (symptom + impairment) as well as categorical (cut-off) and dimensional scoring.

RESULTS

Agreement between impairment and other illness parameters showed considerable variation as a function of type of parameter, disorder, and informant, but to lesser extent age and gender. Many youth who met impairment cut-off for specific disorders did not meet symptom cut-off. Conversely, most youth who met symptom cut-off were impaired. Symptom cut-off evidenced greater convergence with impairment cut-off than combined symptom + impairment cut-offs. Severity of impairment was moderately to highly correlated with number and severity of symptoms. Parents' and teachers' ratings indicated little disorder-specific agreement about youth who met impairment cut-off, symptom cut-off, or combined symptom + impairment cut-off. Therefore, sole reliance on one informant greatly underestimates the pervasiveness of impairment.

CONCLUSION

Findings are consistent with the notion that each illness parameter represents a unique conceptual construct, which has important clinical and research implications.

Association of schizophrenia spectrum and autism spectrum disorder (ASD) symptoms in children with ASD and clinic controls

OBJECTIVE

This study examines relations between the severity of specific symptoms of schizophrenia spectrum disorder (SSD) and severity of the three defining symptom domains of autism spectrum disorder (ASD) in children with ASD (N=147) and child psychiatry outpatient referrals (Controls; N=339).

METHOD

Participants were subdivided into four groups depending on ASD status (±) and whether they met symptom criteria for attention-deficit/hyperactivity disorder (±ADHD). Their mothers and teachers evaluated them with a DSM-IV-referenced rating scale.

RESULTS

Correlations between schizoid personality symptoms and ASD social skills deficits were moderate to large, and this was true for children with ASD and Controls, regardless of ADHD status, and for mother's and teachers' ratings. Conversely, severity of hallucinations, delusions, and disorganized thinking were minimally correlated with ASD severity with the exception of Controls with ADHD. The disorganized behavior and negative symptoms of schizophrenia evidenced the strongest pattern of associations with ASD symptoms, and this was particularly true for children with co-morbid ADHD (±ASD, all three ASD symptom dimensions), and for teachers' ratings of all four groups. Nevertheless, there was considerable variability in relations for specific symptoms across informants and groups. Correlations between SSD symptom severity and IQ were generally low, particularly among the ASD Only group and for all teacher-rated symptoms.

CONCLUSION

Associations between ASD and SSD symptoms were often dimension-specific, and this was particularly evident in children without ADHD (±ASD; mothers' ratings). Findings were interpreted as supporting the deconstruction of complex clinical phenotypes as a means of better understanding interrelations among psychiatric syndromes.