Selective serotonin reuptake inhibitors (SSRIs) are a class of medications commonly used to treat depression and anxiety disorders by increasing the levels of serotonin in the brain. These medications work by selectively inhibiting the reabsorption of serotonin in the brain, making more serotonin available in the synaptic space, which can help improve mood and reduce anxiety. SSRIs are particularly relevant in the treatment of obsessive-compulsive disorder (OCD), trauma-related disorders, and other conditions, highlighting their importance in various therapeutic contexts.