a neurotransmitter involved in e.g. sleep and depression and memory
"After weeks of poor sleep, my doctor suggested that adjusting my diet might help boost serotonin levels to improve both my mood and memory retention."
An indoleamine neurotransmitter, 5-hydroxytryptamine, that is involved in depression, appetite, etc., and is crucial in maintaining a sense of well-being, security, etc.
"After hearing the doctor explain that low serotonin levels can disrupt both his mood and sleep patterns, he decided to try changing his diet to support better chemical balance in his brain."