Abstract
Serotonin reuptake inhibitors and other serotonin‐related drugs are widely used to treat psychiatric disorders, but their therapeutic effects are inadequate and often accompanied by severe side effects, and their mechanisms of action are unclear. One reason for this may be that previous studies have used neurotoxin or pharmacological methods, and thus the possibility of secondary, compensatory, or non‐selective effects could not be ruled out. However, with the rapid development of optogenetics and gene editing technologies in recent years, the above problems can theoretically be avoided. This paper will introduce some examples of our research using these technologies to elucidate the serotonergic pathways involved in depression and its treatment.