The Dopamine Hypothesis of Autism Spectrum Disorder Revisited: Current Status and Future Prospects

2021 ◽  
pp. 1-11
Author(s):  
Denis Pavăl ◽  
Ioana Valentina Micluția

Autism spectrum disorder (ASD) comprises a group of neurodevelopmental disorders characterized by social deficits and stereotyped behaviors. Despite intensive research, its etiopathogenesis remains largely unclear. Although studies consistently reported dopaminergic anomalies, a coherent dopaminergic model of ASD was lacking until recently. In 2017, we provided a theoretical framework for a “dopamine hypothesis of ASD” which proposed that autistic behavior arises from a dysfunctional midbrain dopaminergic system. Namely, we hypothesized that malfunction of 2 critical circuits originating in the midbrain, that is, the mesocorticolimbic and nigrostriatal pathways, generates the core behavioral features of ASD. Moreover, we provided key predictions of our model along with testing means. Since then, a notable number of studies referenced our work and numerous others provided support for our model. To account for these developments, we review all these recent data and discuss their implications. Furthermore, in the light of these new insights, we further refine and reconceptualize our model, debating on the possibility that various etiologies of ASD converge upon a dysfunctional midbrain dopaminergic system. In addition, we discuss future prospects, providing new means of testing our hypothesis, as well as its limitations. Along these lines, we aimed to provide a model which, if confirmed, could provide a better understanding of the etiopathogenesis of ASD along with new therapeutic strategies.

2017 ◽  
Vol 39 (5) ◽  
pp. 355-360 ◽  
Author(s):  
Denis Pavăl

Autism spectrum disorder (ASD) comprises a group of neurodevelopmental disorders characterized by social deficits and stereotyped behaviors. While several theories have emerged, the pathogenesis of ASD remains unknown. Although studies report dopamine signaling abnormalities in autistic patients, a coherent dopamine hypothesis which could link neurobiology to behavior in ASD is currently lacking. In this paper, we present such a hypothesis by proposing that autistic behavior arises from dysfunctions in the midbrain dopaminergic system. We hypothesize that a dysfunction of the mesocorticolimbic circuit leads to social deficits, while a dysfunction of the nigrostriatal circuit leads to stereotyped behaviors. Furthermore, we discuss 2 key predictions of our hypothesis, with emphasis on clinical and therapeutic aspects. First, we argue that dopaminergic dysfunctions in the same circuits should associate with autistic-like behavior in nonautistic subjects. Concerning this, we discuss the case of PANDAS (pediatric autoimmune neuropsychiatric disorder associated with streptococcal infections) which displays behaviors similar to those of ASD, presumed to arise from dopaminergic dysfunctions. Second, we argue that providing dopamine modulators to autistic subjects should lead to a behavioral improvement. Regarding this, we present clinical studies of dopamine antagonists which seem to have improving effects on autistic behavior. Furthermore, we explore the means of testing our hypothesis by using neuroreceptor imaging, which could provide comprehensive evidence for dopamine signaling dysfunctions in autistic subjects. Lastly, we discuss the limitations of our hypothesis. Along these lines, we aim to provide a dopaminergic model of ASD which might lead to a better understanding of the ASD pathogenesis.


2018 ◽  
Vol 61 (11) ◽  
pp. 2629-2640 ◽  
Author(s):  
Connie Kasari ◽  
Alexandra Sturm ◽  
Wendy Shih

Purpose This review article introduces research methods for personalization of intervention. Our goals are to review evidence-based practices for improving social communication impairment in children with autism spectrum disorder generally and then how these practices can be systematized in ways that personalize intervention, especially for children who respond slowly to an initial evidence-based practice. Method The narrative reflects on the current status of modular and targeted interventions on social communication outcomes in the field of autism research. Questions are introduced regarding personalization of interventions that can be addressed through research methods. These research methods include adaptive treatment designs and the Sequential Multiple Assignment Randomized Trial. Examples of empirical studies using research designs are presented to answer questions of personalization. Conclusion Bridging the gap between research studies and clinical practice can be advanced by research that attempts to answer questions pertinent to the broad heterogeneity in children with autism spectrum disorder, their response to interventions, and the fact that a single intervention is not effective for all children. Presentation Video https://doi.org/10.23641/asha.7298021


mSphere ◽  
2020 ◽  
Vol 5 (6) ◽  
Author(s):  
Yu Chen ◽  
Hui Fang ◽  
Chunyan Li ◽  
Guojun Wu ◽  
Ting Xu ◽  
...  

Gut microbiota may contribute to the pathogenesis and development of autism spectrum disorder. The maternal gut microbiota influences offspring gut microbial structure and composition.


2019 ◽  
Vol 9 (1) ◽  
pp. 33-43
Author(s):  
Nicolas Garel ◽  
Patricia Garel

Background: Despite increased attention and recognition of autism spectrum disorders, many patients suffering from these disorders remain undiagnosed or are diagnosed late due to their subtle clinical presentation. The challenge for clinicians working in the field of mental health is not in screening and diagnosing young children showing typical signs of autism spectrum disorders, but rather in identifying patients at the high-functioning end of the spectrum whose intellectual abilities mask their social deficits. Objective: Because therapeutic interventions differ radically once the diagnosis of ASD has been made, it is important to understand the trajectory of those adolescents and identify clues that could help raise the diagnosis of ASD earlier. Methods: Records of eight adolescents with a late diagnosis of ASD were retrospectively reviewed to identify relevant clinical features that were overlooked in childhood and early adolescence. Results: The patients were previously misdiagnosed with multiple mental health disorders. These cases showed striking similarities in terms of developmental history, reasons for misdiagnosis, and the clinical picture at the time of ASD recognition. The cases were characterized by complex and fluctuating symptomatology, including depression, anxiety, behavioural problems, self-injurious behaviour and suicidal thoughts. Their Autism Spectrum Disorder (ASD) went previously undiagnosed due to the individual’s intelligence and learning abilities, which masked their social deficits and developmental irregularities. Signs of ASD were continuously present since childhood in all the eight cases. Once the developmental histories and the psychiatric evaluation of these adolescents were done by psychiatrists with appropriate knowledge of autism, the diagnosis of ASD was made. Conclusion: The ASD hypothesis should be raised in the presence of confusing symptoms that do not respond to usual treatment and are accompanied by an irregular developmental background. It is indeed a difficult diagnosis to make; however, the focused clinician can note subtle signs of ASD despite the intellectual learning of social codes. Family history, developmental irregularities, rigidity, difficulty in spontaneously understanding emotions, discomfort in groups and the need to be alone are significant indicators to recognize. Once the diagnosis has been considered, it must be confirmed or rejected by an experienced multidisciplinary team. The challenge for clinicians working in the field of mental health is not in screening and diagnosing young children showing typical signs of ASD, but rather in identifying patients who are at high-functioning end of the spectrum whose intellectual abilities mask their social deficits.


2019 ◽  
Vol 34 (6) ◽  
pp. 1094-1094
Author(s):  
A Garagozzo ◽  
L Katz ◽  
M Scott ◽  
S Hunter

Abstract Objective Comorbid Autism Spectrum Disorder (ASD) and ADHD are associated with greater symptom severity, including social impairment. Furthering work by Lerner, Pothoff, and Hunter (2015), we sought to identify unique and shared factors that contribute to parent-reported social deficits in children with ADHD, ASD, and ADHD+ASD. We hypothesized attention, hyperactivity, and motor skills would predict social deficits in ADHD, while functional communication and motor skills would predict social deficits in ASD; and additively, all factors would predict social deficits in ADHD+ASD. Method Utilizing a clinical database, we identified 236 participants (4-21 years; Mage = 10.6; 71% male; 28% African American; FSIQ M = 94.31) with diagnoses of ADHD, ASD, and ADHD+ASD. We examined FSIQ from the WISC-4/5, WPPSI-3, or DAS-2, motor skills and social impairment from the SIB-R and attention, hyperactivity, and functional communication from the BASC-2/3. Results Using hierarchical linear regression and controlling for FSIQ, hypotheses were partially supported. FSIQ was controlled for in each group. For ADHD, hyperactivity, functional communication, and motor skills contributed significantly to the model (p < .001), while for ASD, motor skills contributed significantly to the model (p < .001). For ASD + ADHD, functional communication and motor skills contributed significantly to the model (p < .001) Conclusion Results support previous findings that motor deficits and functional communication are associated with social impairment in children with ADHD and ASD, independently and comorbidly. This suggests that targeting motor dysfunction and functional communication concurrently may be effective for improving social interaction skills in children with ADHD +ASD.


2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Hojin Cho ◽  
Chul Hoon Kim ◽  
Elizabeth Quattrocki Knight ◽  
Hye Won Oh ◽  
Bumhee Park ◽  
...  

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