Severe depression is a mental health disorder characterized by persistent feelings of sadness, loss of interest or pleasure in activities, changes in appetite or sleep patterns, low energy levels, difficulty concentrating or making decisions, feelings of worthlessness or guilt, and sometimes thoughts of self-harm or suicide.
Major Depressive Disorder is a specific diagnosis used by mental health professionals to describe severe depression that lasts for at least two weeks and significantly impairs functioning.
SSRIs are a class of antidepressant medications commonly prescribed to treat severe depression. They work by increasing the levels of serotonin in the brain, which helps improve mood.