Positioning of Esketamine Treatment in the Real-world Management of Depression

This study is looking at how esketamine (a fast-acting nasal spray antidepressant) is being used in real-world practice for people with treatment-resistant depression — meaning depression that hasn't improved despite trying at least two antidepressant medications. **You may be eligible if...** - You are 18–65 years old - You have been diagnosed with major depressive disorder (MDD) and are currently depressed - You have tried at least 2 antidepressant medications at adequate doses without enough relief - You are currently on an antidepressant or therapy that you plan to continue - You can understand and provide consent **You may NOT be eligible if...** - You have a diagnosis of bipolar disorder, schizophrenia, or active substance use disorder - You are pregnant or breastfeeding - You take high-dose benzodiazepines (the equivalent of more than 6 mg lorazepam per day) - You use herbal supplements like St. John's Wort - You have a history of uncontrolled seizures, severe uncontrolled high blood pressure, or certain heart or vascular conditions - You are currently using stimulants like methylphenidate or amphetamines (unless you can stop for the study) Talk to your doctor to see if this trial is right for you.