Persistent depressed mood most of the day, nearly every day
Markedly diminished interest or pleasure in most activities
Significant changes in appetite or weight
Insomnia or hypersomnia
Psychomotor agitation or retardation
Fatigue or loss of energy
Feelings of worthlessness or excessive guilt
Diminished ability to think, concentrate, or make decisions
Recurrent thoughts of death or suicidal thoughts
Symptoms present for at least two weeks
Symptoms causing clinically significant distress or impairment
Assessment of symptom severity, duration, and frequency
Review of personal and family psychiatric history
Medical evaluation to rule out thyroid disorders, anemia, vitamin deficiencies, and other causes
Review of medications and substance use
Screening with validated questionnaires such as PHQ-9
Clinical interview by a qualified mental health professional
Evaluation for bipolar disorder, anxiety, and other coexisting conditions
Assessment of suicide risk and immediate safety concerns