Celexa 40 mg contains citalopram, a selective serotonin reuptake inhibitor used as part of prescription treatment for major depressive disorder in adults. The 40 mg strength is one of the available tablet strengths and should only be taken according to a healthcare professional’s instructions. Citalopram treatment may require careful monitoring because it can cause side effects and may interact with certain medicines. The medication also has important precautions involving heart rhythm changes, serotonin syndrome, bleeding risk, and discontinuation effects. Patients should discuss their medical history and current medications with a qualified healthcare professional before starting or changing treatment. Following the prescribed schedule and seeking professional guidance when concerns arise are important parts of responsible medication management.