Selective serotonin reuptake inhibitors (SSRIs) are the primary pharmacological intervention for Depersonalization-derealization disorder, targeting serotonergic dysfunction by increasing synaptic serotonin levels and modulating neurotransmitter activity in the brain. These medications aim to reduce anxiety, stabilize mood, and potentially ameliorate the dissociative symptoms by enhancing neural connectivity and reducing hyperarousal in the limbic and prefrontal cortical regions.