Autism overflows: increasing prevalence and proliferating theories.

Area of Science:

• Neurodevelopmental disorders
• Autism Spectrum Disorder (ASD) research
• Public health trends in autism

Background:

• Increasing prevalence of autism spectrum disorder (ASD) necessitates explanation and synthesis of current theories.
• The measles-mumps-rubella (MMR) vaccine and thimerosal link to autism is a controversial, widely discussed theory.
• Other proposed factors for rising ASD prevalence include diagnostic changes, increased services, and greater public awareness.

Purpose of the Study:

• To review the lack of explanation for increasing autism prevalence.
• To examine the absence of a synthesized theory for autism.
• To address the challenges in autism research due to heterogeneity.

Main Methods:

• Selective review of existing literature on autism prevalence and theories.
• Analysis of proposed causes for increasing autism rates.
• Examination of challenges posed by autism's heterogeneity.

Main Results:

• No single explanation exists for the sharp increase in autism prevalence.
• Proliferating theories of autism lack a unifying synthesis.
• Heterogeneity in brain deficits, behaviors, and genetics complicates theory development.

Conclusions:

• Autism's increasing prevalence strains research efforts for predictive theories.
• Despite decades of research, a standard causal synthesis for autism remains elusive.
• Future research should consider autism as an aggregation of distinct disorders impacting sociality, communication, and cognition.