Which trio of neurotransmitters is associated with autism?

• A. GABA, Serotonin, and Glutamate
• B. Norepinephrine, Dopamine, and Acetylcholine
• C. GABA, Norepinephrine, and Dopamine
• D. Serotonin, Dopamine, and Norepinephrine

Answer: (A)

Autism is thought to arise in part from an imbalance between inhibitory and excitatory signaling in the brain, with GABA as the main inhibitory transmitter and glutamate as the main excitatory one. In many studies, reduced GABAergic inhibition and increased glutamatergic activity have been linked to the sensory differences, atypical connectivity, and developmental changes seen in autism. Serotonin also plays a significant role in neurodevelopment and social behavior, and abnormalities in serotonergic signaling are commonly observed in individuals with autism, influencing mood, cognition, and development. Put together, these three neurotransamine systems—GABA, serotonin, and glutamate—best capture the neurochemical patterns most consistently associated with autism. Other neurotransmitter groups (like norepinephrine, dopamine, acetylcholine) are important for other functions and disorders, but they are not the trio most consistently tied to autism neurochemistry.