Carbamazepine, an anticonvulsant and mood stabilizer, modulates neuronal excitability by blocking voltage-gated sodium channels and reducing glutamatergic neurotransmission. In Depersonalization-derealization disorder, it may help stabilize limbic system activity and reduce aberrant neuronal firing, potentially alleviating symptoms of detachment and perceptual disturbances. Its use in DPDR is considered off-label and primarily based on its efficacy in managing neuropsychiatric symptoms.