We would like to determine whether a modified version of LSD (TD-0148A), which does not induce hallucinations, has antidepressant effects that can be applied to patients with depressive disorders. We will investigate whether TD-0148A can change the physical structure of neurons, as other antidepressants do. Furthermore, we will use an animal model to determine whether TD-0148A can reverse the negative effects of chronic stress, whish is a leading cause of depression in people. These findings can represent a breakthrough in depression treatment, as TD-0148A has a better safety profile compared to LSD and other drugs that induce hallucinations.