Which of the following conditions is sertraline primarily prescribed to treat?

Sertraline is primarily prescribed to treat Major Depressive Disorder (MDD) as it is classified as a selective serotonin reuptake inhibitor (SSRI). SSRIs work by increasing the levels of serotonin in the brain, which is a neurotransmitter that significantly impacts mood and emotional well-being. By enhancing serotonin transmission, sertraline effectively alleviates symptoms of depression, making it a first-line treatment choice for MDD.

The other options, while representing real conditions, are not the primary indications for sertraline. Severe migraines are typically managed with a different class of medications such as triptans or NSAIDs. Chronic pain often requires a combination of pain management strategies, including analgesics or other treatments, instead of SSRIs. Severe insomnia may be treated with medications specifically designed for sleep disorders, though some SSRIs can have sedative effects, they are not primarily used for treating insomnia on their own. Thus, sertraline's primary role in treating Major Depressive Disorder highlights its effectiveness in addressing that particular mental health condition.