Quo vadis DSM-6? An expert survey on the classification, diagnosis, and differential diagnosis of body-focused repetitive behaviors.

BACKGROUND: Many conditions we now call body-focused repetitive behaviors (BFRBs) have been subject to research for several decades, most notably trichotillomania and skin picking. However, the American Psychiatric Association did not combine these conditions into a single category, body-focused repetitive behavior disorders (BFRBDs), until the fifth edition of the DSM (2013). Several aspects of the disorder remain uncertain and controversial. For example, ongoing debate surrounds which specific conditions fall under this diagnostic category and how to best differentiate BFRBs from conditions such as nonsuicidal self-injury (NSSI). The current article presents results from a survey of experts' opinions on diagnostic criteria, with the goal of refining the diagnostic criteria. METHOD: We contacted experts on BFRB via various sources and invited them to complete an online survey on the phenomenology, classification, and differential diagnosis of BFRB. We also inquired about possible alternative syndrome labels (e.g., body-focused habit). RESULTS: Data from the final sample of 50 experts demonstrates that most experts agree with the present classification of BFRB/BFRBD as an obsessive-compulsive and related disorder and recommend retaining the labels BFRB or BFRBD. The experts considered the following conditions BFRB, with an agreement of over 60%: trichotillomania, skin picking, dermatophagia, nail biting, and lip-cheek biting. Mixed results emerged for awake bruxism and thumb sucking in adults. Only a minority regarded night bruxism and knuckle cracking as BFRB. To differentiate BFRB from NSSI, the experts noted that the motive behind the urge (self-harm/injury versus release of tension) should be considered. Analyses of a sub-sample of experts with at least six years of clinical and/or research experience yielded results compatible with those of the entire sample. DISCUSSION: The survey supports the usefulness of the BFRBD diagnostic entity. However, some criteria require further refinement. Future editions of the DSM should more explicitly delineate which conditions qualify as BFRB. Furthermore, it is important to give more attention to the primary motivation behind BFRB to distinguish it from NSSI and potentially from stereotypic movement behavior.

Structure of Restricted Repetitive Behaviors of Individuals Referred for Autism Spectrum Disorder Assessment.

PURPOSE: Restricted and/or repetitive displays of behavior, interests, or activities (RRBs) are one of the core symptom domains of autism spectrum disorder (ASD). Current and past research indicates two 'clusters' of RRBs in children with ASD: repetitive sensorimotor (e.g., hand/finger and more complex motor mannerisms) and insistence on sameness (e.g., resistance to changes in the environment) behaviors. The current study aims to fill a gap by examining how RRBs may diverge in individuals with ASD and with other neurodevelopmental disorders (ONDD) in a clinical sample. METHODS: A total of 558 individuals were seen at a tertiary care clinic for a comprehensive clinical assessment of ASD. The sample was split into ASD (n = 292 individuals) and ONDD (n = 266) groups based on clinical diagnosis. Exploratory factor analyses were conducted using Autism Diagnostic Interview-Revised (ADI-R) RRB item scores for the overall sample, the ASD group, and the ONDD group. RESULTS: Exploratory factor analysis of ADI-R RRB items indicated a 2-factor solution for the full sample and ASD group. Items loaded onto two factors comprised of "Repetitive Sensorimotor" and "Insistence on Sameness" behaviors, consistent with previous literature. Results demonstrated a unique loading pattern for the non-ASD group, with items clustering into "Higher Order" (e.g., circumscribed interests) and "Lower Order" (e.g., hand and finger mannerisms) behaviors. CONCLUSION: The results of the current study may point towards using RRBs to guide screening of children who are referred for an ASD evaluation to better identify children who are at higher risk of having ASD.

More similar than different: Characterizing special interests in autistic boys and girls based on caregiver report.

Almost all autistic youths have special interests (SIs), which are focused, intense areas of passion and interest in a particular topic. Emerging research suggests that there are gender differences in SIs among autistic youth; however, commonly used measures that assess for the presence of SIs may not fully capture the granular nature of those differences between autistic boys and girls. Characterizing these differences is important for autism identification in girls, as SIs in autistic girls may often be overlooked by caregivers, teachers, and clinicians due to their more "typical" and more socially oriented content areas compared to autistic boys. This study therefore aimed to more fully characterize gender differences in SIs using a newly developed caregiver-report measure of SIs (the Special Interests Survey; SIS). Caregivers of 1921 autistic youth completed the SIS. Analyses revealed many similarities between boys and girls; there were no gender differences in mean age SI onset, caregivers' perceptions of uniqueness or interferences of endorsed SIs, or duration of previous SIs. There were gender differences in endorsement of less than half (39%) of the SI categories measured, and there were minor differences in the number of endorsed current and past SIs. Categories with significant gender differences fell along typical gender lines (e.g., more boys interested in math and construction, more girls interested in animals and arts/crafts). This study extends the growing literature on SIs and gender differences in autism and has important implications for supporting autistic youth and their families.

Characterizing associations between emotion dysregulation, anxiety, and repetitive behaviors in autistic youth with intellectual disability.

There is a paucity of research that explores associations between emotion dysregulation and the expression and severity of core and co-occurring characteristics of autism spectrum disorder (ASD), especially in autistic youth with co-occurring intellectual disability (ID). This study explored the interplay between developmental characteristics and emotion dysregulation, anxiety, and specific subtypes of RRBs that are elevated in autistic youth with co-occurring ID. Generalized additive models demonstrated that age, sex, language level, dysregulation, and anxiety showed unique patterns of association with subtypes of RRBs in a sample of 150 autistic youth with co-occurring ID who are non-speaking or minimally verbal. More specifically, higher anxiety levels were significantly associated with elevations in repetitive sensory motor behaviors (RSMB), self-injurious behaviors (SIB), insistence on sameness (IS), and unusual interests (UI). While emotion dysregulation was a significant predictor of UI, it demonstrated positive, albeit not significant, associations with the intensity of SIB and RSMB. Language level was a significant predictor of RSMB, such that the intensity of RSMB was higher for individuals who were non-speaking relative to those who spoke in single words. These findings provide preliminary insights into patterns of associations between emotion dysregulation, anxiety, and specific subdomains of RRBs in autistic youth with ID.

Association of Irritability with Restricted, Repetitive Behaviors and Social Communication Challenges in Autistic Youth.

Although affective irritability is a common and concerning problem for autistic youth, limited research has examined relations among core autism characteristics and irritability. Therefore, this study investigated potential associations among types of restricted/repetitive behaviors (RRBs) and social communication challenges and irritability in autistic children and adolescents. Participants were 107 autistic youth recruited from a university-based autism clinical research program. Two hierarchical multiple regressions were conducted with Affective Reactivity Index as the dependent variable. Covariates were entered at step 1, followed by the independent variables of interest at step 2. For the first model, independent variables of interest were Repetitive Behavior Scale-Revised subscales: stereotyped behavior, self-injurious behavior, compulsive behavior, ritualistic behavior, sameness behavior, and restricted behavior. For the second model, independent variables of interest were Social Responsiveness Scale, Second Edition subscales: social awareness, social cognitive, social communication, and social motivation. Irritability was significantly associated with several categories of RRBs (i.e., insistence on sameness, stereotypic behavior, and restricted interests/activities). Nonetheless, irritability was not associated with categories of social communication and interaction challenges in autistic youth. Results from this study indicated differing associations between core autism characteristics and affective irritability. Findings highlight the importance of differentiating types of restricted, repetitive behaviors and social communication and interaction challenges in conceptualizing mental health concerns in autistic youth.

Effects of Medical Cannabis Treatment for Autistic Children on Anxiety and Restricted and Repetitive Behaviors and Interests: An Open-Label Study.

Background: The literature supports the benefits of medical cannabis for core and comorbid symptoms in autistic individuals and anxiety-related symptoms in individuals without autism. However, no study has specifically investigated how cannabidiol (CBD)-rich cannabis affects anxiety subtypes in autistic children or its relationship with restricted and repetitive behaviors and interests (RRBI). Understanding the effects of CBD-rich cannabis treatment on anxiety subtypes and RRBI could offer more precise treatment approaches to managing anxiety symptoms and reducing RRBI frequency in autistic children. Objectives: To examine (1) the impact of CBD-rich cannabis treatment on autistic children's (1a) anxiety levels and subtypes and (1 b) RRBI and subtypes and (2) whether changes in anxiety explain changes in RRBI following cannabis treatment. Method: In this open-label study, we analyzed data from 65 autistic children (5-12 years) who had participated in research on the effects of CBD-rich cannabis on children with autism. Their parents completed the Repetitive Behavior Scale-revised to assess the frequency and severity of six subgroups of their children's recurrent behaviors and the Screen for Child Anxiety-Related Emotional Disorders for symptoms related to five types of anxiety disorders. They completed these assessments at three time points: (T1) before treatment, (T2) after 3 months, and (T3) after 6 months of treatment. Results: The results indicated reduced RRBI and symptoms related to various anxiety subtypes in autistic children following 6 months of CBD-rich cannabis treatment. Specifically, we observed significant differences in the autistic children's overall anxiety and in some anxiety subtypes (i.e., general, social, panic, and separation anxieties). Significant improvements were observed in RRBI, including the total score, and specifically in compulsive, ritualistic, and sameness behaviors. Our findings revealed that reduced anxiety, particularly within the panic- and separation-related subtypes, predicted a subsequent decrease in RRBI, specifically sameness behaviors, following cannabis treatment. Conclusions: The findings of the cannabis treatment's potential benefits for alleviating anxiety symptoms, leading to reduced RRBI, may provide evidence for the meaningful relationship between these variables and for the potential benefits of cannabis treatment for autistic children. We strongly recommend further double-blind, placebo-controlled studies using standardized assessments to validate these findings.

Body-Focused Repetitive Behaviors in Patients with FOXP1 Syndrome: An International Cross-Sectional Survey-Based Study.

Introduction: FOXP1 syndrome is a rare neurodevelopmental disorder due to forkhead box protein 1 (FOXP1) gene mutations and is associated with intellectual disability, dysmorphic features, and autism spectrum disorder. We aimed to assess body-focused repetitive behavior (BFRB) prevalence in this patient population using a cross-sectional survey-based study. Methods: A validated survey assessing for BFRBs was administered to parents attending the International FOXP1 Foundation conference on June 21, 2023, and was sent to a FOXP1 syndrome listserv. Results: Excoriation disorder, onychophagia, onychotillomania, and trichotillomania were reported by 58.6%, 38.6%, 29.7%, and 10.0% of subjects, with 63.4%, 59.3%, 54.5%, and 14.3% having moderate to severe disease, respectively. Overall, 28.6%, 30.0%, and 10.0% had one, two, and three BFRBs, respectively. Conclusion: Prevalence of BFRBs is high among FOXP1 syndrome patients surveyed, affecting quality of life for patients and their families and causing significant sequelae.

Cannabidiol is a behavioral modulator in BTBR mouse model of idiopathic autism.

Introduction: The prevalence of Autism Spectrum Disorder (ASD) has drastically risen over the last two decades and is currently estimated to affect 1 in 36 children in the U.S., according to the center for disease control (CDC). This heterogenous neurodevelopmental disorder is characterized by impaired social interactions, communication deficits, and repetitive behaviors plus restricted interest. Autistic individuals also commonly present with a myriad of comorbidities, such as attention deficit hyperactivity disorder, anxiety, and seizures. To date, a pharmacological intervention for the treatment of core autistic symptoms has not been identified. Cannabidiol (CBD), the major nonpsychoactive constituent of Cannabis sativa, is suggested to have multiple therapeutic applications, but its effect(s) on idiopathic autism is unknown. We hypothesized that CBD will effectively attenuate the autism-like behaviors and autism-associated comorbid behaviors in BTBR T+Itpr3tf/J (BTBR) mice, an established mouse model of idiopathic ASD. Methods: Male BTBR mice were injected intraperitoneally with either vehicle, 20 mg/kg CBD or 50 mg/kg CBD daily for two weeks beginning at postnatal day 21 ± 3. On the final treatment day, a battery of behavioral assays were used to evaluate the effects of CBD on the BTBR mice, as compared to age-matched, vehicle-treated C57BL/6 J mice. Results: High dose (50 mg/kg) CBD treatment attenuated the elevated repetitive self-grooming behavior and hyperlocomotion in BTBR mice. The social deficits exhibited by the control BTBR mice were rescued by the 20 mg/kg CBD treatment. Discussion: Our data indicate that different doses for CBD are needed for treating specific ASD-like behaviors. Together, our results suggest that CBD may be an effective drug to ameliorate repetitive/restricted behaviors, social deficits, and autism-associated hyperactivity.

Comparing the 'When' and the 'Where' of Electrocortical Activity in Patients with Tourette Syndrome, Body-Focused Repetitive Behaviors, and Obsessive Compulsive Disorder.

Background/Objectives: Tourette Syndrome (TS), Obsessive Compulsive Disorder (OCD), and Body-Focused Repetitive Behaviors (BFRB) are three disorders that share many similarities in terms of phenomenology, neuroanatomy, and functionality. However, despite the literature pointing toward a plausible spectrum of these disorders, only a few studies have compared them. Studying the neurocognitive processes using Event-Related Potentials (ERPs) offers the advantage of assessing brain activity with excellent temporal resolution. The ERP components can then reflect specific processes known to be potentially affected by these disorders. Our first goal is to characterize 'when' in the processing stream group differences are the most prominent. The second goal is to identify 'where' in the brain the group discrepancies could be. Methods: Participants with TS (n = 24), OCD (n = 18), and BFRB (n = 16) were matched to a control group (n = 59) and were recorded with 58 EEG electrodes during a visual counting oddball task. Three ERP components were extracted (i.e., P200, N200, and P300), and generating sources were modelized with Standardized Low-Resolution Electromagnetic Tomography. Results: We showed no group differences for the P200 and N200 when controlling for anxiety and depressive symptoms, suggesting that the early cognitive processes reflected by these components are relatively intact in these populations. Our results also showed a decrease in the later anterior P300 oddball effect for the TS and OCD groups, whereas an intact oddball effect was observed for the BFRB group. Source localization analyses with sLORETA revealed activations in the lingual and middle occipital gyrus for the OCD group, distinguishing it from the other two clinical groups and the controls. Conclusions: It seems that both TS and OCD groups share deficits in anterior P300 activation but reflect distinct brain-generating source activations.

Selective vulnerability of the ventral hippocampus-prelimbic cortex axis parvalbumin interneuron network underlies learning deficits of fragile X mice.

High-penetrance mutations affecting mental health can involve genes ubiquitously expressed in the brain. Whether the specific patterns of dysfunctions result from ubiquitous circuit deficits or might reflect selective vulnerabilities of targetable subnetworks has remained unclear. Here, we determine how loss of ubiquitously expressed fragile X mental retardation protein (FMRP), the cause of fragile X syndrome, affects brain networks in Fmr1y/- mice. We find that in wild-type mice, area-specific knockout of FMRP in the adult mimics behavioral consequences of area-specific silencing. By contrast, the functional axis linking the ventral hippocampus (vH) to the prelimbic cortex (PreL) is selectively affected in constitutive Fmr1y/- mice. A chronic alteration in late-born parvalbumin interneuron networks across the vH-PreL axis rescued by VIP signaling specifically accounts for deficits in vH-PreL theta-band network coherence, ensemble assembly, and learning functions of Fmr1y/- mice. Therefore, vH-PreL axis function exhibits a selective vulnerability to loss of FMRP in the vH or PreL, leading to learning and memory dysfunctions in fragile X mice.

Review of Management Considerations for Excoriation Disorder in Older Adults.

Excoriation disorder (ED) is defined as compulsive skin picking that results in skin damage and emotional distress. Optimal management of ED includes individualized treatment plans consisting of psychotherapies, behavioral and pharmacologic interventions. Compared with younger populations, older adults are at increased risk for poor outcomes, such as infection and hospitalization, and require unique management considerations. Risk factors that contribute to disease burden include age-related changes to the skin and underlying medical and psychiatric comorbidities. A literature review was conducted on ED yielding limited evidence exclusive to older adults. The authors suggest a therapeutic approach to ED in older adults based on available evidence and experience from inpatient and outpatient psychiatric settings. Finally, opportunities for future research are highlighted.

Descriptive Analysis of Social Interaction and Communication Skills of Autistic Children According to Sibling Status and Characteristics.

OBJECTIVE: Sibling relationships in early childhood can have a positive impact on children's social interaction and communication skills. Similarly, autistic children can benefit from interactions with their siblings, who can serve as readily available partners for social interaction. However, there is a lack of research on the effects of siblings based on specific characteristics of the sibling. Therefore, the aim of this study is to compare social interactions and communication skills of autistic children based on sibling status and characteristics. METHODS: We conducted a retrospective data review involving 895 autistic children and their siblings at Seoul National University Bundang Hospital. Variety of diagnostic assessments or questionnaires were administered. Based on the characteristics of the data, Quade's test for nonparametric analysis of covariance was used to compare autism-related symptoms and levels of functioning of the autistic child according to 1) sibling status, 2) birth order, 3) sex, and 4) diagnosis of the sibling. Pearson correlation was used to explore associations between the sibling age gap and different clinical scores. RESULTS: Having siblings was associated with fewer difficulties in restricted and repetitive behaviors. Based on the comparison of the Autism Diagnostic Interview-Revised scores, autistic children with multiple siblings demonstrated better nonverbal behaviors. Autistic children with autistic siblings experienced greater difficulties in social interactions and communications, such as peer relationships, sharing enjoyment, and engaging in social imitative play. CONCLUSION: The study revealed differences in social interactions and communication skills of autistic children based on sibling status, birth order, affected sibling, age gap, and sex.

Is Self-Help Dangerous? Examination of Adverse Effects of a Psychological Internet-Based Self-Help Intervention for Body-Focused Repetitive Behavior (Free From BFRB).

Despite the proven effectiveness of psychotherapy for psychiatric disorders, adverse events or unwanted effects may occur. Unwanted effects, however, are rarely assessed. In self-help interventions, which usually are not supported by a therapist, such effects have received even less attention even though special caution is needed regarding unwanted effects such as those related to misapplication. For the present study, we present the newly developed Positive and Negative Effects of Psychotherapy Scale for Internet-Based Intervention (PANEPS-I) and examine possible unwanted effects of an internet-based self-help intervention in individuals with body-focused repetitive behaviors (BFRBs), aggregating three different techniques: habit reversal training (HRT), decoupling (DC), and decoupling in sensu (DC-is). Some HRT users have expressed concern that the suppression of the problematic behavior could lead to rebound effects, but this has not been examined rigorously. Following baseline assessment, 141 participants with at least one BFRB were randomly assigned to two intervention groups that differed only with respect to the delivery mode (video, manual); the content was the same. After 6 weeks, a post-assessment was conducted. Unwanted effects were assessed using the PANEPS-I. A total of 70% of the participants (both treatment groups combined) reported at least one positive effect of the intervention. Negative effects were reported by 14-92% of participants, depending on the effect. The highest agreement rates were found for "no positive goal orientation" (52.5%), "did not address personal problems" (48.8%), "time/performance pressure" (20.9%), shame (16.3%), and concerns about data privacy (14.3%). Participants in the manual intervention group reported unethical procedures (e.g., data privacy concerns) more often (Cohen's d = .44) than those in the video intervention group. Responders reported more positive effects and nonresponders more malpractice (|d| = .80, .54, respectively). HRT users (self-report) showed no significant differences compared to nonusers regarding negative effects. Stepwise hierarchical regression analyses indicated a dose-response relationship for reported positive effects and malpractice. Side effects may occur in any kind of intervention. Usage of HRT did not lead to more reported negative effects compared to nonusage. To improve the quality and effectiveness and ensure the safety of the user, especially those using digital self-help interventions, it is important to regularly assess unintended effects since there is no supervision of the patient in unguided self-help interventions.

Prevalence of body-focused repetitive behaviors in a diverse population sample - rates across age, gender, race and education.

BACKGROUND: Prevalence estimates for body-focused repetitive behaviors (BFRBs) such as trichotillomania differ greatly across studies owing to several confounding factors (e.g. different criteria). For the present study, we recruited a diverse online sample to provide estimates for nine subtypes of BFRBs and body-focused repetitive disorders (BFRDs). METHODS: The final sample comprised 1481 individuals from the general population. Several precautions were taken to recruit a diverse sample and to exclude participants with low reliability. We matched participants on gender, race, education and age range to allow unbiased interpretation. RESULTS: While almost all participants acknowledged at least one BFRB in their lifetime (97.1%), the rate for BFRDs was 24%. Nail biting (11.4%), dermatophagia (8.7%), skin picking (8.2%), and lip-cheek biting (7.9%) were the most frequent BFRDs. Whereas men showed more lifetime BFRBs, the rate of BFRDs was higher in women than in men. Rates of BFRDs were low in older participants, especially after the age of 40. Overall, BFRBs and BFRDs were more prevalent in White than in non-White individuals. Education did not show a strong association with BFRB/BFRDs. DISCUSSION: BFRBs are ubiquitous. More severe forms, BFRDs, manifest in approximately one out of four people. In view of the often-irreversible somatic sequelae (e.g. scars) BFRBs/BFRDs deserve greater diagnostic and therapeutic attention by clinicians working in both psychology/psychiatry and somatic medicine (especially dermatology and dentistry).

Restricted and repetitive behaviors and association with cognition and adaptive functioning in children with autism spectrum disorder in Singapore.

Background: One of the core features of autism spectrum disorder (ASD) is restricted, repetitive patterns of behavior, interests and activities (RRBs). RRBs are known to adversely affect cognition and adaptive functioning. We explored the relationship of RRBs with cognition and adaptive functioning in children with ASD in an Asian setting. Methods: This cross-sectional study was conducted at a tertiary developmental pediatrics center in Singapore from September 2019 to October 2021. Parent-child dyads (parents and their children ≤7 years old diagnosed with ASD) were recruited. Parents completed the Repetitive Behavior Questionnaire-2 (RBQ-2), which reports total score and two subscales - Motor/Sensory Behaviors (RBQ-2 MS) and Rigidity/Routines/Preoccupation with Restricted Interests (RBQ-2 RRPRI). Standardized assessments included Mullen Scales of Early Learning (MSEL) and Vineland Adaptive Behavior Scales (VABS-II). Data analysis utilized descriptive statistics and Pearson's correlation. Results: Parents of 113 children [75.2% male, mean (SD) age 5.0 (1.2) years] participated. Median (IQR) RBQ-2 score was 29.0 (11.0). Significant negative correlations (adjusted for age, gender and family history of ASD) were observed for total RBQ-2 scores with MSEL ELC scores (r = -0.248, n = 101, p = 0.014) and VABS-II ABC scores (r = -0.281, n = 88, p = 0.009). Specifically, these correlations of fair strength were seen only with the RBQ-2 MS subscale for both ELC (r = -0.321, n = 101, p = 0.001) and ABC (r = -0.3478, n = 88, p = 0.001). Conclusion: In children with ASD, severity of RRBs correlated with adverse cognition and adaptive functioning measures in our study, consistent with Western literature. While our study does not show causality, it adds to literature serving as a foundation for further research for both clinicians and researchers to target RRBs in improving outcomes with children in ASD.

The Effect of Anxiety and Autism Symptom Severity on Restricted and Repetitive Behaviors Over Time in Children with Fragile X Syndrome.

Background: Restricted and repetitive behaviors (RRBs) are highly prevalent and reduce function in individuals with fragile X syndrome (FXS). As transdiagnostic features of intellectual disability, elevated rates of RRBs in FXS could represent various underlying known co-occurring conditions in FXS such as anxiety or autism spectrum disorder (ASD), yet this distinction has not been investigated. Further, delineating whether RRBs are more indicative of anxiety or ASD in FXS may clarify phenotypic profiles within FXS and improve differential assessment. Methods: We longitudinally examined the potentially independent or multiplicative effect of ASD and anxiety symptom severity on RRBs in 60 children with FXS. Anxiety was measured using the Child Behavior Checklist (CBCL), ASD severity was measured using the Childhood Autism Rating Scale (CARS), and RRBs were measured using The Repetitive Behavior Scale - Revised (RBS-R). We estimated a series of moderated regression models with anxiety and ASD symptoms at the initial assessment (Time 1) as predictors of RRBs at the outcome assessment two years later (Time 2), along with an anxiety-by-ASD interaction term to determine the potential multiplicative effect of these co-occurring conditions on RRBs. Results: Results identified a significant interaction between ASD and anxiety symptom severity at the initial assessment that predicted elevated sensory-motor RRBs two years later. Increased sensory-motor RRBs were predicted by elevated ASD symptoms only when anxiety symptom severity was low. Likewise, increased sensory-motor RRBs were predicted by elevated anxiety symptoms only when ASD symptom severity was low. Interestingly, this relationship was isolated to Sensory-Motor RRBs, with evidence that it could also apply to total RRBs. Conclusions: Findings suggest that ASD and anxiety exert independent and differential effects on Sensory-Motor RRBs when at high severity levels and a multiplicative effect when at moderate levels.

Repetitive Behaviors in Alzheimer's Disease: A Systematic Review and Meta-Analysis.

BACKGROUND: Repetitive behaviors (RBs) are a well-known symptom of Alzheimer's disease (AD); however, they have been little studied and have not been the subject of any specific literature review. OBJECTIVE: To conduct a systematic review of all studies to document RBs in AD. METHODS: An extensive literature search combining five databases and a meta-analysis were conducted to investigate the frequency, nature, and cognitive correlates of RBs in AD. RESULTS: Ten studies were included in the review. Seven studies out of ten investigated the frequency of RBs in patients with AD, which ranged from 52.3% to 87%. A meta-analysis showed an overall frequency of 66.3% (95% CI: 55.5; 77.1) of patients exhibiting RBs in AD, but important heterogeneity was observed between studies. Three studies investigated the predominant nature of RBs in AD. Verbal RBs, complex behavioral stereotypies, and simple motor stereotypies have been identified to different degrees depending on the level of dementia. Most verbal RBs are underpinned by episodic memory impairment, while simple motor stereotypies and complex behavioral stereotypies are mostly underpinned by executive dysfunction. CONCLUSIONS: The current review seems to suggest that there are two types of mechanisms underpinning RBs involved in AD. The first is observed especially in the mild stages of the disease and is mediated by episodic memory impairment. The second occurs later and is mediated by executive impairment. Additional studies should be conducted to improve the knowledge about RBs in AD and thus improve their management.Systematic review registration number: PROSPERO 2022: CRD42022310027.

Changes in the severity of autism symptom domains are related to mental health challenges during middle childhood.

LAY ABSTRACT: For many autistic children, the severity of their autism symptoms changes during middle childhood. We studied whether these changes are associated with the emergence of other mental health challenges such as anxiety and attention-deficit hyperactivity disorder. Children who had increased social-communication challenges had more anxiety and attention-deficit hyperactivity disorder symptoms and disruptive behavior problems than other children. Children who decreased their restricted and repetitive behaviors, on the contrary, had more anxiety. We discuss why these changes in autism symptoms may lead to increases in other mental health concerns.

Independent and combined effects of astaxanthin and omega-3 on behavioral deficits and molecular changes in a prenatal valproic acid model of autism in rats.

Objectives: Autism is a devastating neurodevelopmental disorder and recent studies showed that omega-3 or astaxanthin might reduce autistic symptoms due to their anti-inflammatory properties. Therefore, we investigated the effects of omega-3 and astaxanthin on the VPA-induced autism model of rats.Material and Methods: Female Wistar albino pups (n = 40) were grouped as control, autistic, astaxanthin (2 mg/kg), omega-3 (200 mg/kg), and astaxanthin (2 mg/kg)+omega-3 (200 mg/kg). All groups except the control were prenatally exposed to VPA. Astaxanthin and omega-3 were orally administered from the postnatal day 41 to 68 and behavioral tests were performed between day 69 and 73. The rats were decapitated 24 h after the behavioral tests and hippocampal and prefrontal cytokines and 5-HT levels were analyzed by ELISA.Results: VPA rats have increased grooming behavior while decreased sociability (SI), social preference index (SPI), discrimination index (DI), and prepulse inhibition (PPI) compared to control. Additionally, IL-1ß, IL-6, TNF-α, and IFN-γ levels increased while IL-10 and 5-HT levels decreased in both brain regions. Astaxanthin treatment raised SI, SPI, DI, PPI, and prefrontal IL-10 levels. It also raised 5-HT levels and decreased IL-6 levels in both brain regions. Omega-3 and astaxanthin + omega-3 increased the SI, SPI, DI, and PPI and decreased grooming behavior. Moreover, they increased IL-10 and 5-HT levels whereas decreased IL-1ß, IL-6, TNF-α, IFN-γ levels in both brain regions.Conclusions: Our results showed that VPA administration mimicked the behavioral and molecular changes of autism in rats. Single and combined administration of astaxanthin and omega-3 improved the autistic-like behavioral and molecular changes in the VPA model of rats.

Sex Differences in the Developmental Trajectories of Autism Spectrum Disorder.

Purpose of Review: Females and males are disproportionately diagnosed with autism, a sex difference that has historically represented this neurodevelopmental condition. The current review examines lifespan developmental trajectories of autism based on sex to elucidate behavioral phenotypic differences that may contribute to differential rates of diagnosis. Recent Findings: We review sex differences in diagnostic criteria: social communication and restricted interests/repetitive behaviors (RRBs). Results suggest RRBs are more indicative of a diagnosis in males, whereas social differences are more indicative of a diagnosis in females. Factors contributing to a later diagnosis in females include social strengths (camouflaging) and diagnostic overshadowing. Summary: Sex differences in diagnostic criteria may contribute to differential rates of identification in males and females. Sex differences are most pronounced when assessing naturalistic social communication instead of reliance on standardized measure. Numerous future directions are identified including increasing samples of sub-threshold autistic females and evaluating longitudinal sex differences.