Neurotransmitter Associated with Mood Regulation

Neurotransmitters are critical to the functioning of the nervous system, influencing both physiological processes and behavior.

One particular neurotransmitter, known for its role in mood regulation and reward processing, has been linked with conditions such as depression and anxiety. Dysregulation of this neurotransmitter can lead to significant affective disorders.

Which neurotransmitter is primarily associated with these functions?