Final answer:
Serotonin synthesis in individuals with Autism Spectrum Disorder (ASD) may be decreased, which can contribute to the symptoms and social deficits observed in people with ASD.
Step-by-step explanation:
Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterized by impaired social interaction and communication abilities. The synthesis of serotonin, a neurotransmitter associated with mood regulation and social behavior, may be decreased in individuals with ASD. This decrease in serotonin synthesis has been hypothesized to contribute to the symptoms and social deficits observed in people with ASD.