**4. Conclusions**

Despite the few studies with cinnamic acids in animal depression models, the results indicate their potential applicability as candidates for antidepressant drugs. The studies discussed show that the antidepressant action of these natural products occurs via important neurotransmitters such as serotonin, as well as via the participation of inflammation-related metabolites such as AA-COX-2/5-LOX and BDNF. In some reports, there is a similarity in the mechanism of action with commercial antidepressant drugs. This data confirms the therapeutic potential of these compounds against behavioral disorders, such as depression. The availability of these compounds via commercial companies or laboratory synthesis, and the low cost of some acids, such as ferulic acid, make them interesting prototypes to advance the development of new antidepressant agents.

**Author Contributions:** Investigation, Methodology and Writing—Original Draft Preparation, L.R.L.D., M.T.d.S.S., J.N.B.; Formal Analysis, R.N.d.A.; Writing—Review and Editing, Supervision, D.P.d.S.

**Funding:** This research received no external funding.

**Acknowledgments:** This research was supported by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).

**Conflicts of Interest:** The authors declare no conflict of interest
