Final answer:
A major depressive episode must last for a minimum of 2 weeks, according to the DSM-5.
Step-by-step explanation:
To be classified as a major depressive episode, depression must last for a minimum of 2 weeks. This duration is specified in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), which is a widely recognized diagnostic manual used by mental health professionals. During this period, the individual experiences a severely depressed mood along with other symptoms such as loss of interest or pleasure in activities, changes in appetite or sleep patterns, difficulty concentrating, feelings of worthlessness, and thoughts of self-harm