Major Depressive Disorder (MDD) is a prevalent mental health condition characterized by persistent feelings of sadness, hopelessness, and worthlessness. There are several synonyms for MDD, including clinical depression, major depression, unipolar depression, and recurrent depressive disorder. These terms are often used interchangeably to refer to the same mental health disorder. Other related terms include bipolar depression, postpartum depression, and seasonal affective disorder. It is essential to recognize the signs and symptoms of MDD, including low mood, loss of interest in activities, changes in appetite, sleep disturbances, and suicidal thoughts. Treatment options for MDD can include therapy, medication, and lifestyle changes. Seeking professional help is crucial for individuals experiencing depressive symptoms.