Feeling sad occasionally is normal. But when emptiness, fatigue, and hopelessness linger for weeks and interfere with daily life, it may be clinical depression. Major Depressive Disorder (MDD) affects over 300 million people worldwide and is a leading cause of disability. Recognizing the symptoms and diagnostic criteria is the first step toward healing.

This guide explains the official DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition) criteria for depression, helping you understand when professional help is needed.

The 9 Core Symptoms of Depression

According to the DSM-5, at least five of the following nine symptoms must be present during the same two-week period, and at least one of the symptoms must be either (1) depressed mood or (2) loss of interest or pleasure.

Duration and Severity Specifiers

Depression is not a one-size-fits-all diagnosis. Clinicians also specify:

• Mild: Few symptoms beyond the required five, minor functional impairment.
• Moderate: Between mild and severe.
• Severe: Many symptoms beyond required, marked functional impairment, possibly with psychotic features.
• With anxious distress, mixed features, melancholic features, atypical features, or peripartum onset.

A single episode is called Major Depressive Disorder, Single Episode. If episodes recur (at least two months apart), it’s Recurrent.

When to Seek Help

If you or someone you know has experienced several of these symptoms for more than two weeks – especially suicidal thoughts – please reach out to a mental health professional. Depression is treatable with psychotherapy, medication, lifestyle changes, or a combination.