What is Autism?

Autism Spectrum Disorder is a developmental condition that affects an individual’s cognitive, social, and emotional functioning[1]. It is a spectrum, meaning that its symptoms and severity vary widely among individuals. While some individuals may have significant impairments in social interactions, others may demonstrate only mild deficits. The spectrum nature of autism means that no two people with autism experience the same set of challenges or strengths. Autism is not a disease but rather a neurodevelopmental condition that typically appears in early childhood. It is diagnosed more often in boys than in girls, with current estimates suggesting that 1 in 36 children and 1 in 45 adults are affected by the disorder[2].

Autism can be diagnosed at various ages, but most individuals are diagnosed around the age of 5, even though signs may be present as early as age 2[2]. Diagnosing autism early can help in providing the necessary support and interventions that can assist in improving long-term outcomes. Furthermore, autism often co-occurs with other psychiatric and medical conditions, a phenomenon known as comorbidity[2]. Common comorbidities include Attention-Deficit/Hyperactivity Disorder, anxiety disorders, depression, gastrointestinal issues, seizures, and sleep disorders[2]. Understanding these co-occurring conditions is crucial for providing comprehensive care for individuals with autism. Other sources on Autism symptoms and care can be found here.

Symptoms

Symptoms of autism involve deficits in social communication and interactions and restrictive or repetitive behaviors or interests[1].

• Lack of facial expressions (by 9 months )
• Delayed language skills
• Delayed movement skills
• Avoiding eye contact
• Lack of social gestures ( shaking hands or waving goodbye by 12 months old)
• Disinterest in social interaction (by 24 months old)
• Difficulties identifying others’ emotions
• Obsessive interests
• Strong negative emotional response in response to minor changes
• Excessive repeating of words or phrases
• Strong reaction to certain sensory stimuli
• Dependance on strong routines

The Gut- Brain Connection

Research on mice that lack gut microbiota showed that these animals display altered social behaviors and increased anxiety-like traits[3]. This suggests that gut bacteria contribute to brain function and behavior, and these interactions can be seen in Figure 1. Additionally, gut microbiota influence neurotransmitter systems, including dopamine and serotonin, both of which play critical roles in ASD-related symptoms[3].

The Enteric nervous system regulates gut function and shares neurotransmitters and signaling pathways with the central nervous system. Dysregulation of these pathways has been observed in Autism, supporting the idea that gut dysfunction may be linked to behavioral and neurological symptoms[3]. Studies have also found differences in the expression of synaptic proteins in Autism models, reinforcing the potential impact of gut microbiota on brain development and function[3].

Conclusion

In conclusion, autism is a complex and multifaceted disorder that requires a personalized and holistic approach to diagnosis and treatment. Ongoing research into the gut-brain connection may eventually uncover new strategies to improve the quality of life for individuals on the autism spectrum.

 

 

 

 

[1] Centers for Disease Control and Prevention. (2024, November 25). About autism spectrum disorder. Centers for Disease Control and Prevention. https://www.cdc.gov/autism/about/index.html

[3]DiCarlo, G. E., & Wallace, M. T. (2022, February). Modeling dopamine dysfunction in autism spectrum disorder: From invertebrates to vertebrates. Neuroscience and biobehavioral reviews. https://pmc.ncbi.nlm.nih.gov/articles/PMC8792250/

[4]Liu, L., Huh, J., & Shah, K. (2022, March). Microbiota and the gut-brain-axis: Implications for new therapeutic design in the CNS. EBioMedicine. https://pubmed.ncbi.nlm.nih.gov/35255456/