What are the key symptoms of Major Depressive Disorder?

Major Depressive Disorder (MDD) is characterized by a range of symptoms that significantly affect a person's emotional, physical, and cognitive well-being. The key symptoms include persistent sadness, which reflects a pervasive feeling of emptiness or hopelessness that lasts for most of the day, nearly every day. Fatigue is another critical symptom, often described as a profound lack of energy and motivation that can hinder daily activities and productivity. Sleep disturbances, which can manifest as insomnia (difficulty sleeping) or hypersomnia (sleeping too much), further contribute to the overall decline in an individual's quality of life.

These symptoms are typically present for a minimum duration, usually measured in weeks, and must interfere with the individual’s ability to function in daily life. The combination of these elements leads to the debilitating nature of MDD, distinguishing it from other mental health conditions, such as anxiety disorders or mood disorders that might present with different symptom profiles. Understanding these key symptoms is essential for proper diagnosis and treatment planning.