Albizia julibrissin, commonly known as the silk tree or mimosa, has been used in traditional Chinese medicine (TCM) for centuries. In TCM, it is referred to as "He Huan Pi" (the bark) or "He Huan Hua" (the flower) and is traditionally used to calm the spirit, relieve emotional constraint, and treat symptoms such as anxiety, depression, and insomnia. These uses are based on the belief that the herb nourishes the heart and soothes the mind.

The rationale for linking Albizia julibrissin to the serotonin system stems from its traditional use as a mood-supporting agent. Serotonin is a neurotransmitter associated with mood regulation, and herbalists sometimes infer that calming or antidepressant herbs may act, at least in part, via serotonergic pathways. However, direct scientific evidence supporting Albizia julibrissin’s effect on serotonin levels or receptors in humans is limited. Some preliminary animal studies suggest possible antidepressant-like and anxiolytic effects, potentially through modulation of neurotransmitters, but these findings are not conclusive and have not been widely replicated.

Overall, the use of Albizia julibrissin to support the serotonin system is primarily justified by traditional use, with some weak preclinical evidence suggesting a possible mechanism. High-quality clinical trials and mechanistic studies in humans are lacking.