Observed prevalence of autism spectrum disorders in two Norwegian counties

A systematic review and meta-analysis on the prevalence of mental disorders among children and adolescents in Europe

Most mental disorders appear by age 14, but in most cases, they remain undiagnosed and untreated well into adulthood. A scoping review showed an absence of systematic reviews that address prevalence rates of mental disorders among children and adolescents in Europe that are based on community studies conducted between 2015 and 2020. To estimate the updated pooled prevalence of Anxiety Disorder, Depressive Disorder, Attention Deficit Hyperactivity Disorder (ADHD), Conduct Disorder (CD), Oppositional Defiant Disorder (ODD), Autism Spectrum Disorder, Eating Disorders, Substance Use Disorders (SUD), among children and adolescents living in Europe, a search strategy was conducted using MEDLINE, Embase and Psych Info and studies were also identified from reference lists and gray literature. Eligible studies were evaluated for reliability, validity, and bias. Trends of prevalence rates for each mental disorder were calculated. Almost one in five young people in Europe were found to suffer from a mental disorder, with a pooled prevalence rate of 15.5%. Anxiety disorders had the highest pooled prevalence rate (7.9% (95% CI 5.1-11.8%, I2: 98.0%)), followed by ADHD (2.9% (95% CI 1.2-6.9%, I2 = 94.3%)), ODD (1.9% (95% CI 1.0-3.7%, I2 = 98.4%)), depressive disorder (1.7% (95% CI 1.0-2.9%, I2 = 97.7%)), CD (1.5% (95% CI 0.6-3.8%, I2 = 98.8%)) and ASD (1.4% (95% CI 0.4-5.4%, I2 = 99.7%). No studies on SUD were identified. The mental health of children and adolescents may be improved by introducing routine screening, refining diagnostic sensitivity, raising awareness of mental disorders, minimizing stigma and socioeconomic inequality, as well as developing early intervention services. These facilitators of good mental health need to be prioritized, especially at a time of unprecedented risk factors for poor mental health.

Mapping autism's research landscape: trends in autism screening and its alignment with sustainable development goals

Introduction

Autism Spectrum Disorder is a complex neurodevelopmental syndrome that profoundly affects social interactions, communication, and sensory perception. The research traced the evolution of autism research from 2011-2022, specifically focusing on the screening and diagnosis of children and students.

Methods

Through an analysis of 12,262 publications using the PRISMA framework, bibliographic coupling, science mapping, and citation analysis, this study illuminates the growth trajectory of ASD research and significant disparities in diagnosis and services.

Results

The study indicates an increasing trend in autism research, with a strong representation of female authorship. Open Access journals show a higher average citation impact compared to their closed counterparts. A keyword co-occurrence analysis revealed four central research themes: Child Development and Support Systems, Early Identification and Intervention, Prevalence and Etiology, and Mental Health. The pandemic's onset has prioritized research areas like mental health, telehealth, and service accessibility.

Discussion

Recommendations on a global level stress the importance of developing timely biological markers for ASD, amplifying Disability Inclusion research, and personalizing mental health services to bridge these critical service gaps. These strategies, underpinned by interdisciplinary collaboration and telehealth innovation, particularly in low-resource settings, can offer a roadmap for inclusive, context-sensitive interventions at local levels that directly support SDG3's aim for health and well-being for all.

Autistic Characteristics in a Nationally Representative Clinical Sample of Adolescents Seeking Medical Gender-Affirming Treatment in Norway

PURPOSE

Several studies have reported on the intersection of autism and gender incongruence (GI) in clinical populations. This study aims to investigate autistic characteristics and registered autism spectrum diagnoses (ASD) in a clinical cohort of 83 adolescents referred to the National Gender Team for Children and Adolescents in Norway during 2020.

METHODS

Parents completed the Social Responsiveness Scale (SRS). Background information and registered psychiatric diagnoses were extracted from patient files.

RESULTS

The results showed that 25% of the participants scored within the clinical range on the SRS: 27.4% of adolescents who were assigned female at birth (AFAB) and 19.0% of adolescents who were assigned male at birth (AMAB). AFAB had significantly higher scores on SRS Total Scale and the Social Motivation and Autistic Mannerisms subscales compared to the female norm group. AMAB had higher scores on the Social Motivation subscale and lower scores on the Social Awareness subscale, compared to the male norm population. Information from patient files revealed that 67.5% had one or more registered psychiatric diagnosis. 9.6% had received an ASD diagnosis, all AFAB. 18.1% had received an attention deficit hyperactivity disorder (ADHD) diagnosis. The most common psychiatric diagnoses were depression (25.3%) and anxiety disorders (18.1%). Further, 44.6% had a history of self-harm, and 15.7% had a history of a suicide attempt.

CONCLUSION

The results showed an overrepresentation of ASD diagnoses and autistic characteristics measured by SRS for AFAB. There was an overrepresentation of psychiatric diagnoses for both the AFAB and the AMAB group in this study sample. Implications for treatment and future research are discussed.

Global prevalence of Rett syndrome: systematic review and meta-analysis

BACKGROUND

Rett syndrome is a rare, severe neurodevelopmental disorder. Almost all cases occur in girls, in association with spontaneous (non-inherited) mutations involving the methyl-CpG-binding protein 2 gene located on the X chromosome. Diagnostic criteria for typical Rett syndrome require a period of regression, followed by recovery or stabilization, and fulfillment of all four main criteria (loss of purposeful hand skills, loss of spoken language, gait abnormalities, and stereotypic hand movements). Our objective was to estimate the prevalence of Rett syndrome in the general population, stratified by sex.

METHODS

We conducted a search of PubMed, Embase, Web of Science, Cochrane Library, LILACS, and LIVIVO to retrieve studies published in English between Jan. 1, 2000, and June 30, 2021. Pooled prevalence with a 95% confidence interval (CI) was estimated using a random-effects meta-analysis based on a generalized linear mixed model with a logit link.

RESULTS

Ten eligible studies were identified (all in females), with a combined sample size of 9.57 million women and 673 Rett syndrome cases. The pooled prevalence estimate (random effects) was 7.1 per 100,000 females (95% CI: 4.8, 10.5, heterogeneity p < 0.001). Despite greatly variable precision of estimation, all estimates were compatible with a prevalence range of approximately 5 to 10 cases per 100,000 females based on their respective 95% CIs.

CONCLUSION

These findings may facilitate planning of therapeutic trials in this indication in terms of target sample size and accrual times.

The global prevalence of autism spectrum disorder: A three-level meta-analysis

Autism spectrum disorder (ASD) is one the most disabling developmental disorders, imposing an extremely high economic burden. Obtaining as accurate prevalence estimates as possible is crucial to guide governments in planning policies for identification and intervention for individuals with ASD and their relatives. The precision of prevalence estimates can be heightened by summative analyses of the data collected around the world. To that end, we conducted a three-level mixed-effects meta-analysis. A systematic search of the Web of Science, PubMed, EMBASE, and PsycINFO databases from 2000 up to 13 July 2020 was performed, and reference lists of previous reviews and existing databases of prevalence studies were screened. Overall, 79 studies were included in the analysis of ASD and 59-in the analysis of previously existing relevant diagnoses: 30 for Autistic Disorder (AD), 15 for Asperger Syndrome (AS), and 14 for Atypical Autism (AA) and Pervasive Developmental Disorder - Not Otherwise Specified (PDD-NOS); these research reports covered the period from 1994 to 2019. Pooled prevalence estimates were 0.72% (95% CI = 0.61-0.85) for ASD, 0.25% (95% CI = 0.18-0.33) for AD, 0.13% (95% CI = 0.07-0.20) for AS, and 0.18% (95% CI = 0.10-0.28) for the combined group of AA and PDD-NOS. Estimates were higher (1) for the studies that used records-review surveillance rather than other designs; (2) in North America compared with other geographical regions; and (3) in high-income compared with lower-income countries. The highest prevalence estimates were registered in the USA. There was an increase in autism prevalence estimates over time. The prevalence was also significantly higher for children aged between 6 and 12 years compared to children under the age of 5 and over the age of 13 years.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42019131525, identifier CRD42019131525.

The global prevalence of autism spectrum disorder: a comprehensive systematic review and meta-analysis

Background

Autism spectrum disorder (ASD) is one of the serious developmental disorders that is usually diagnosed below the age of three years. Although the severity of the disease’s symptoms varies from patient to patient, the ability to communicate with others is affected in all forms of ASD. This study aimed to determine the prevalence of ASD in high-risk groups by continent.

Methods

The present study was conducted by systematic review and meta-analysis from 2008 to July 2021. Databases such as Science Direct, PubMed, Scopus, SID, Magiran, Web of Science (WoS), and Google Scholar from 2008 to July 2021 were searched to find related studies. Data were analysed using Comprehensive Meta-Analysis software (Version 2).

Results

A total of 74 studies with 30,212,757 participants were included in this study. The prevalence of ASD in the world was 0.6% (95% confidence interval: 0.4–1%). Subgroup analyses indicated that the prevalence of ASD in Asia, America, Europe, Africa and Australia was 0.4% (95% CI: 0.1–1), 1% (95% CI: 0.8–1.1), 0.5% (95% CI: 0.2–1), 1% (95% CI: 0.3–3.1), 1.7% (95% CI: 0.5–6.1) respectively.

Conclusion

ASD imposes a heavy health burden on communities around the world. Early detection of ASD can reduce the incidence of developmental disorders and improve patients’ communication skills. Therefore, health policymakers need to be aware of the prevalence and increasing trend of ASD to implement appropriate planning and interventions to reduce its consequences.

Mealtime Behaviors and Food Preferences of Students with Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by a lack of social communication and restrictive, repetitive behaviors or interests. This study aimed to examine the mealtime behaviors and food preferences of students with ASD. An online questionnaire on mealtime behavior and food preferences of ASD students was conducted by caregivers including parents, and the average age of ASD students was 14.1 ± 6.1. The analysis of mealtime behavior resulted in classification into three clusters: cluster 1, the "low-level problematic mealtime behavior group"; cluster 2, the "mid-level problematic mealtime behavior group"; and cluster 3, the "high-level problematic mealtime behavior group". Cluster 1 included older students than other clusters and their own specific dietary rituals. Meanwhile, cluster 3 included younger students than other clusters, high-level problematic mealtime behavior, and a low preference for food. In particular, there were significant differences in age and food preference for each subdivided ASD group according to their eating behaviors. Therefore, the content and method of nutrition education for ASD students' needs a detailed approach according to the characteristics of each group.

An Exploratory Study of Executive Function Development in Children with Autism, after Receiving Early Intensive Behavioral Training

Objective: To examine the development of executive functions, in preschool children with autism spectrum disorders (ASD), receiving early intensive behavioral training (EIBI). Method: Executive functions (EF) were assessed with The Behavior Rating Inventory of Executive Function - Preschool Version (BRIEF-P), by parents and preschool teachers at the time of diagnostic assessment and after 15 months of EIBI intervention. Ten children with ASD (M = 2.9 years, nine males) participated in the study. Reliable Change Index scores were computed for each of the participants in order to investigate any significant change in BRIEF-P T-scores. Results: Three children showed a significant improvement in EF, based on parent ratings. Four children showed a significant improvement in EF based on preschool teacher ratings. Conclusion: Findings indicating a reliable improvement in one third of preschool children with ASD receiving EIBI are encouraging but need to be replicated in larger scale controlled studies.

Spatiotemporal distribution of autism spectrum disorder prevalence among birth cohorts during 2000-2011 in Israel

PURPOSE

Studies indicate an apparent sharp increasing trend in autism spectrum disorder (ASD) incidence and prevalence worldwide. This nationwide study aims at depicting ASD prevalence distribution in Israel in both space and time.

METHODS

Based on data from Israel National Insurance Institute, the study population included all children born in Israel 2000-2011 (n = 1,786,194), of whom 11,699 (0.655%) were subsequently diagnosed with ASD (until December 31, 2016). Prevalence was calculated and mapped by dividing the number of ASD cases within each year of birth by the number of births during that year, for each spatial unit, and similarly for several spatiotemporal levels of aggregation.

RESULTS

ASD prevalence varies substantially across different geographic areas in Israel, with considerably higher prevalence concentrated in central Israel. Strong associations were found between locality-level socioeconomic index, ethnicity, and peripherality and ASD prevalence, and even after adjustment for them, excess prevalence for ASD still persisted in certain localities. No spatial dependence of prevalence, with and without adjustment for the locality-level variables, was found (Moran's I = -0.000546, -0.00335, respectively).

CONCLUSIONS

Our findings provide important insights regarding health disparities affecting ASD diagnosis, directing further health policy intervention and further research.

Piloting the Use of a Short Observation List for ASD-Symptoms in Day-Care: Challenges and Further Possibilities

Early symptoms of autism spectrum disorder (ASD) develop through the second year of life, making a stable ASD diagnosis possible around 24 months of age. However, in general, children with ASD are diagnosed later. In this study we explored the use of a short observation list to detect symptoms associated with ASD in children 12-24 months of age attending typical day-care centers. The results indicate that a short observation list used by day-care teachers does not reveal sufficient properties to be independently used in young children in day-care centers. Further studies should explore multiple and repeated measures for early detection of symptoms associated with ASD in typical day-care centers.

Vocal and motor behaviors as a possible expression of gastrointestinal problems in preschoolers with Autism Spectrum Disorder

Background

Gastrointestinal (GI) problems are one of the most frequent comorbidities in Autism Spectrum Disorder (ASD) but can be under-recognized due to the concomitant communication difficulties of this population. Accordingly, some associated behaviors (AB) such as verbal and motor behaviors (VB and MB, respectively) have been identified as a possible expression of an underlying GI problem and evaluated through an ad hoc questionnaire (the Associated Behaviors Questionnaire -ABQ-). The aims of this study were to investigate the presence and the type of AB in an Italian sample of ASD preschoolers, and to determine their correlations with GI problems.

Methods

We included 85 ASD preschoolers (mean age 4.14 years; SD 1.08) splitted into two groups (GI and No-GI) through the GI Severity Index instrument. AB were evaluated through the ABQ that includes VB, MB and Changes in overall state (C) clusters. Specific tools were administered to evaluate the ASD core ad associated symptoms, as well as the intellective and adaptive functioning.

Results

The GI group (N = 30) showed significantly higher scores in all the three ABQ areas (VB, MB and C) than the No-GI group (N = 55), with a positive correlation between GI symptoms and some specific AB as well as ABQ Total score. By dividing the whole sample in verbal and non-verbal individuals, both specific and shared AB emerged in the two groups.

Conclusions

Our results alert clinicians to consider behavioral manifestations as a possible expression of GI problems in ASD subjects. Therefore, the evaluation of AB may be useful to identify the presence of GI problems in the ASD populations, and especially in non-verbal ASD children.

Focus on the Social Aspect of Autism

Autism spectrum disorder (ASD) describes a set of neurodevelopmental disorders. Despite extensive ASD research lasting more than 60 years, its causes are still unknown. Without indicating the etiology, its development cannot be stopped. Over the years, both the definition and diagnostic criteria have developed. The number of ASD incidence is rising. The economical aspect should also be highlighted. This disorder presents particular challenges to affected children, their parents and physicians. The research of ASD, physician activities, policy making and raising the level of awareness must be coordinated. Special attention should be paid to the problem among adults with ASD.

Autism Spectrum Disorder: Incidence and Time Trends Over Two Decades in a Population-Based Birth Cohort

We retrospectively identified autism spectrum disorder (ASD) incident cases among 31,220 individuals in a population-based birth cohort based on signs and symptoms uniformly abstracted from medical and educational records. Inclusive and narrow research definitions of ASD (ASD-RI and ASD-RN, respectively) were explored, along with clinical diagnoses of ASD (ASD-C) obtained from the records. The incidence of ASD-RI, ASD-RN, and ASD-C increased significantly from 1985 to 1998, then ASD-RI and ASD-RN plateaued while the rate of ASD-C continued to increase during 1998-2004. The rising incidence of research-defined ASD may reflect improved recognition and documentation of ASD signs and symptoms. Although the frequency of threshold ASD symptoms stabilized, the rate of ASD-C continued to increase, narrowing the gap between clinical ascertainment and symptom documentation.

Kynurenine Pathway in Autism Spectrum Disorders in Children

BACKGROUND

There is increasing evidence that altered immune responses play a role in the pathogenesis of autism spectrum disorders (ASD), together with dysfunction of the serotonergic and glutamatergic systems. Since the kynurenine (KYN) pathway that degrades tryptophan (TRP) is activated in various neuroinflammatory states, we aimed to determine whether this pathway is activated in ASD.

METHODS

Sixty-five pediatric ASD patients (including 52 boys) were enrolled from an epidemiological survey covering 2 counties in Norway; 30 (46.5%) of these patients were diagnosed with childhood autism, 16 (24.6%) with Asperger syndrome, 12 (18.5%) with atypical autism, 1 (1.5%) with Rett syndrome, and 6 (9.2%) with other ASD. The serum levels of the following markers were measured in the children with ASD and compared to those in 30 healthy children: TRP, KYN, kynurenic acid (KA), 3-hydroxykynurenine, and quinolinic acid.

RESULTS

The mean serum level of KA was significantly lower in the ASD group than in the healthy controls (28.97 vs. 34.44 nM, p = 0.040), while the KYN/KA ratio was significantly higher in the ASD group (61.12 vs. 50.39, p = 0.006). The same relative values were found when comparing the childhood autism subgroup with the controls. Also, the mean serum level of TRP was significantly lower in children with a subdiagnosis of childhood autism than in those with Asperger syndrome (67.26 vs. 77.79 μM, p = 0.020).

CONCLUSION

Our study indicates that there is an increased neurotoxic potential and also a possible lower KYN aminotransferase activity in ASD.

Severity of Autism Symptoms and Degree of Attentional Difficulties Predicts Emotional and Behavioral Problems in Children with High-Functioning Autism; a Two-Year Follow-up Study

Children with autism often struggle with emotional and behavioral problems (EBP). This study investigated whether level of autism symptoms, attention problems or verbal IQ at baseline can predict EBP 2 years later in children with High-Functioning Autism (HFA). Thirty-four participants with HFA and 45 typically developing children (TD) (ages 9-16) were assessed with parent ratings of EBP, autism symptoms, attention problems, and a test of verbal IQ. The amount of autism symptoms and degree of attention problems at baseline significantly predicted EBP at follow-up, whereas verbal IQ did not. The findings from this study emphasize the importance of assessing and understanding the consequences of autism symptoms and attention problems when treating EBP in children with HFA. Furthermore, interventions aimed at improving ASD symptoms may positively affect the prevalence of EBP in children with HFA.

What Is the Male-to-Female Ratio in Autism Spectrum Disorder? A Systematic Review and Meta-Analysis

OBJECTIVE

To derive the first systematically calculated estimate of the relative proportion of boys and girls with autism spectrum disorder (ASD) through a meta-analysis of prevalence studies conducted since the introduction of the DSM-IV and the International Classification of Diseases, Tenth Revision.

METHOD

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. The Medline, Embase, and PsycINFO databases were searched, and study quality was rated using a risk-of-bias tool. Random-effects meta-analysis was used. The pooled outcome measurement was the male-to-female odds ratio (MFOR), namely the odds of being male in the group with ASD compared with the non-ASD group. In effect, this is the ASD male-to-female ratio, controlling for the male-to-female ratio among participants without ASD.

RESULTS

Fifty-four studies were analyzed, with 13,784,284 participants, of whom 53,712 had ASD (43,972 boys and 9,740 girls). The overall pooled MFOR was 4.20 (95% CI 3.84-4.60), but there was very substantial between-study variability (I² = 90.9%). High-quality studies had a lower MFOR (3.32; 95% CI 2.88-3.84). Studies that screened the general population to identify participants regardless of whether they already had an ASD diagnosis showed a lower MFOR (3.25; 95% CI 2.93-3.62) than studies that only ascertained participants with a pre-existing ASD diagnosis (MFOR 4.56; 95% CI 4.10-5.07).

CONCLUSION

Of children meeting criteria for ASD, the true male-to-female ratio is not 4:1, as is often assumed; rather, it is closer to 3:1. There appears to be a diagnostic gender bias, meaning that girls who meet criteria for ASD are at disproportionate risk of not receiving a clinical diagnosis.

Changes in the frequency and characteristics of children diagnosed with autistic disorder in two Norwegian cohorts: 1992 and 2009

Background:

Is the increasing prevalence of autistic disorder (AD) a well-documented trend or merely a reflection of the wider recognition of AD among both the public at large and health care professionals? Data from relevant studies are frequently compromised by comparisons of different sites and different diagnostic methods.

Objectives:

To explore changes over time, we reviewed the following: 1) the frequency of AD diagnoses; 2) the characteristics of the diagnosed children; and 3) the ages of the children when initial concerns were addressed and AD diagnoses made.

Method:

We compared the case records of children between the ages of 1 and 17 years who were residing in Nordland County, Norway, and who were diagnosed with AD during two different data collection periods: 1992 (Cohort 1) and 2009 (Cohort 2).

Results:

In Cohort 1, 28 children were diagnosed with AD; 71 children in Cohort 2 received AD diagnoses. The increase was greatest among children with intelligence quotient (IQ) values of at least 70. The proportion of children with genetic syndromes was around 20% in both cohorts. Median age at AD diagnosis did not differ between the two cohorts (4.5 vs. 5.0 years, respectively). When the two cohorts were combined, children with IQ values of 70 or more without a genetic syndrome and those with IQ values of less than 50 with genetic syndromes were diagnosed at approximately the same age (5.5 and 5.3 years, respectively). Both groups were significantly older at diagnosis as compared with children with IQ values of less than 50 without genetic syndromes (3.5 years).

Conclusions:

The increase in the number of children diagnosed with AD is consistent with findings from international studies. Contrary to predictions, the age at diagnosis was not reduced over time. A higher proportion of children with IQ values in the average range in the latter cohort may have contributed to this. A delayed diagnosis of AD among children with genetic syndromes may indicate that early autism symptoms are attributed to the genetic condition. Clinical implications are discussed.

Cytokine Profile in Autism Spectrum Disorders in Children

The pathogenesis of autism spectrum disorders (ASD) is not completely understood, but there is evidence of associations with altered immune responses. The aim of this study was to determine the serum levels of various cytokines in children with ASD and in healthy controls, in order to determine their role in ASD and its diagnostic subgroups. Sixty-five ASD patients were enrolled from an epidemiological survey in Norway, of which 30 were diagnosed with childhood autism, 16 with Asperger syndrome, 12 with atypical autism, 1 with Rett syndrome, and 6 with another ASD diagnosis. The serum levels of 12 cytokines were measured in all of the patients and in 30 healthy children. The cytokine levels did not differ significantly between the ASD group and the healthy controls. However, the interleukin-8 (IL-8) level was significantly higher (6.82 vs 4.58 pg/ml, p = 0.017) while that of IL-10 was significantly lower (2.24 vs 6.49 pg/ml, p = 0.009) in patients with childhood autism than in controls. Furthermore, the IL-8 level was significantly higher in childhood autism than in Asperger syndrome (6.82 vs 4.05 pg/ml, p = 0.013). Our study shows that the cytokine profile of children diagnosed with ASD, regardless of the subdiagnosis, does not differ from healthy controls. However, differentiation into different diagnostic subgroups reveals significantly different levels of IL-8 and IL-10. This indicates that different mechanisms may underlie the different ASD subdiagnoses. Future research into the pathophysiological mechanisms of ASD should pay more attention to the different subdiagnoses of ASD.

Hypothesis on supine sleep, sudden infant death syndrome reduction and association with increasing autism incidence

AIM: To identify a hypothesis on: Supine sleep, sudden infant death syndrome (SIDS) reduction and association with increasing autism incidence.

METHODS: Literature was searched for autism spectrum disorder incidence time trends, with correlation of change-points matching supine sleep campaigns. A mechanistic model expanding the hypothesis was constructed based on further review of epidemiological and other literature on autism.

RESULTS: In five countries (Denmark, United Kingdom, Australia, Israel, United States) with published time trends of autism, change-points coinciding with supine sleep campaigns were identified. The model proposes that supine sleep does not directly cause autism, but increases the likelihood of expression of a subset of autistic criteria in individuals with genetic susceptibility, thereby specifically increasing the incidence of autism without intellectual disability.

CONCLUSION: Supine sleep is likely a physiological stressor, that does reduce SIDS, but at the cost of impact on emotional and social development in the population, a portion of which will be susceptible to, and consequently express autism. A re-evaluation of all benefits and harms of supine sleep is warranted. If the SIDS mechanism proposed and autism model presented can be verified, the research agenda may be better directed, in order to further decrease SIDS, and reduce autism incidence.

The Prevalence of Autism Spectrum Disorders in West Pomeranian and Pomeranian Regions of Poland

BACKGROUND

The prevalence of autism spectrum disorders (ASD) varies worldwide from 1.4/10 000 children in the Arabian Peninsula to 185/10 000 children of Asian population. In Europe, the highest prevalence has been observed in Sweden, while the lowest in Croatia (115/10 000 and 2-3/10 000, respectively). There have been no epidemiological studies on the prevalence of ASD in Polish population. The aim of our study was to assess the prevalence of ASD in children aged 0-16 years, inhabitants of West Pomeranian and Pomeranian regions.

MATERIAL AND METHODS

In total, 2514 children (2038 males, 81.1%) were included. The estimates were based on the government registries, whereas data were obtained from Provincial Disability Services Commissions.

RESULTS

The prevalence of ASD in children aged 0-16 years varies between two regions of Poland - 32/10 000 in West Pomeranian and 38/10 000 in Pomeranian region.

CONCLUSIONS

The average prevalence of ASD was 35/10 000 children and was about 4-fold higher in males (P < 0.05). More studies are necessary.

Differences in autism spectrum disorders incidence by sub-populations in Israel 1992-2009: a total population study

We analyzed data from the Israeli National Insurance Institute (NII). Autism Spectrum Disorder (ASD) incidence was calculated for all children born in Israel 1992-2009, and by population groups. Overall, 9,109 ASD cases among 2,431,649 children were identified. ASD cumulative incidence by age 8 years increased 10-fold during 2000-2011, from 0.49% to 0.49%, while other child disabilities in NII increased only 1.65-fold. There was a consistent increase in ASD incidence with advancing birth cohorts born 1992-2004, stabilizing among those born 2005-2009. ASD rates among Israeli Arabs were substantially lower, and increased about 10 years later than the general population. The findings suggest a role for ASD awareness, accessing of the government benefit, or the way the concept of ASD is perceived.

Gestational/perinatal chlorpyrifos exposure is not associated with autistic-like behaviors in rodents

Although animal models cannot exactly replicate human psychiatric disorders, they may be useful to investigate whether the behaviors associated with certain exposures in animals parallel those observed in people. According to the most current version of the Diagnostic and Statistical Manual of Mental Disorders, autism is diagnosed based on (1) persistent deficits in social communication and social interaction; and (2) the presence of restricted, repetitive patterns of behavior, interests and activities. To address whether developmental chlorpyrifos (CPF) exposure was associated with the development of autistic behaviors, a literature search was conducted to identify studies in rats and mice involving gestational or early postnatal exposure to CPF or CPF oxon (CPO, the active metabolite of CPF) and subsequent behavioral testing to assess behaviors related to autism. A total of 13 studies conducted in six different laboratories were identified. Analysis of these studies found that perinatal CPF exposure was generally associated with (1) no effect or increased social communications; (2) no effect or increased social encounters; (3) no effect, reduced stereotypies, or conflicting findings on stereotypic behaviors; and (4) no effect or increased preference for novelty and reduced anxiety in novel environments. These behavioral findings are generally inconsistent with the types of behaviors that would be expected in children with clinical autism. Based on the results of this analysis of rodent model studies involving CPF/CPO exposure, it cannot be concluded that gestational and/or perinatal CPF exposure is likely to be associated with the development of autism-like behaviors in humans.

Autism spectrum disorders--are they really epidemic?

AIM

The aim of this paper is to report on how different external methodological factors influence estimates of ASD prevalence.

METHODS

PubMed searches was conducted using the search terms, "Autism", "Autistic Disorder", "Autism Spectrum Disorders", "Asperger", "Prevalence" and "epidemiology", in combination. In total 49 studies were included. We also performed a manual search for and reviewed related articles referenced in the original articles.

RESULTS

The reported prevalence rates of ASD vary widely, and so do the methodology used in the studies.

CONCLUSION

There are reasons to argue that the methods used in some studies cause the high prevalence rates reported recently.

Symptoms of ADHD in children with high-functioning autism are related to impaired verbal working memory and verbal delayed recall

Symptoms similar to those found in Attention-Deficit/Hyperactivity Disorder (ADHD) often occur in children with Autism Spectrum Disorders (ASD). The objective of the current study was to compare verbal working memory, acquisition and delayed recall in children with High-Functioning Autism (HFA) to children with ADHD and typically developing children (TDC). Thirty-eight children with HFA, 79 with ADHD and 50 TDC (age 8–17) were assessed with a letter/number sequencing task and a verbal list-learning task. To investigate the possible influence of attention problems in children with HFA, we divided the HFA group into children with (HFA+) or without (HFA−) “attention problems” according to the Child Behaviour Checklist 6–18. The children with HFA+ displayed significant impairment compared to TDC on all three neurocognitive measures, while the children with HFA− were significantly impaired compared to TDC only on the working memory and acquisition measures. In addition, the HFA+ group scored significantly below the HFA− group and the ADHD group on the verbal working memory and delayed recall measures. The results support the proposition that children with HFA+, HFA−, and ADHD differ not only on a clinical level but also on a neurocognitive level which may have implications for treatment.

Children with autism spectrum disorders - the importance of medical investigations

BACKGROUND

Considerable knowledge about medical comorbidity in cases of Autism Spectrum Disorders (ASD) is available, still it is not well established how extensive the medical investigations should be in individual cases. The aim is to explore proportions of possible specific medical conditions in ASD.

METHODS

79 subjects went through extensive medical evaluations according to pre-defined procedures, including medical and developmental history, physical and biomedical investigations.

RESULTS

Clinical neurological findings were quite common, and we found a high number of pathological findings in the additional medical investigations. Our study revealed that these pathological deviations occurred more frequently in patients with childhood autism than in the other diagnostic sub-groups, the exception were chromosomal findings which occurred more often in patients not-diagnosed with childhood autism.

CONCLUSION

Medical and laboratory investigations should still be performed as a consequence of the patient's history, clinical presentations or family history. We should basically continue the use of non-routine and invasive procedures which do not put the patient at some unnecessary risk, in the absence of relevant clinical indications.