A fundamental framework for understanding how the brain regulates behavior, attention, emotions, and higher psychological functions in children. According to this theory, neuronal communication between neurons is carried out through chemical messengers known as neurotransmitters, such as dopamine, serotonin, norepinephrine, and acetylcholine, which transmit signals between cells to coordinate neural activity, cognitive, and emotional-mental functions. These neurotransmitters play a key role in the regulation of attention, motor control, learning, memory, and emotional regulation. They also affect the child’s ability to adapt to the environment and interact effectively in society. The theory suggests that any imbalance of neurotransmitters or their mode of action can lead to cognitive and behavioral difficulties, such as attention deficit hyperactivity disorder, anxiety, depression, or sleep disturbances, highlighting the close link between neurochemistry and neuropsychological functioning. The theory also emphasizes that neurochemical processes are not fixed, but are influenced by environment, learning, nutrition, and genetic factors, reflecting the brain’s flexibility and adaptability (neuroplasticity) even in the presence of initial imbalances. In terms of treatment and early intervention, neurochemical theory helps identify pharmacological and behavioral therapy strategies aimed at modifying or maintaining the activity of these mediators to achieve a neurological balance that promotes learning, attention, behavior control, and emotional and social development of children. As such, this theory provides a scientific framework for understanding the relationship between neurochemistry and behavior, allowing researchers and therapists to develop comprehensive interventions based on a deep understanding of how neurochemical processes affect neuropsychological development and holistic child functioning.