The current study is being conducted in patients with major depression. The study aims to 1) investigate the combined effects of selective serotonin reuptake inhibitor (SSRI) and bupropion compared to SSRI alone on the improvements of depressive symptoms, fatigue, hypersomnia, and neurocognitive functions, 2) observe structural/functional/chemical changes using magnetic resonance imaging (MRI), 3) and examine a relationship between the improvements of depressive symptoms, fatigue, and hypersomnia and the neural changes.

Inclusion Criteria:

• Men and women aged between 20 and 65
• Diagnosis of major depressive disorder (MDD) as assessed by the Structured Clinical Interview for DSM-IV (SCID-IV)
• Individuals who provided written consent for participation.

Exclusion Criteria:

• Presence of any major physical or neurological illness (e.g., head trauma, epilepsy, seizure, stroke, cerebral tumor, multiple sclerosis, cerebrovascular disease, narrow-angle glaucoma, drug hypersensitivity, etc.)
• Diagnosis of any Axis I disorder other than MDD or presence of symptoms requiring hospitalization
• Intelligence quotient (IQ) below 80
• Contraindications to magnetic resonance imaging (e.g., pacemaker implantation, claustrophobia, etc.)
• Unstable medical illness or other abnormalities observed at the screening or laboratory tests
• Women who are pregnant, breastfeeding, or planning pregnancy
• Allergy or tolerance to the clinical trial medication
• Presence of any physical illness that contraindicates the clinical trial medication (e.g., epilepsy, history of uncontrollable narrow-angle glaucoma)
• Use of psychoactive medications that may affect brain imaging findings