Depression
Depression is more than sadness — it is a persistent low mood or loss of interest lasting at least two weeks, often with changes in sleep, appetite, energy, and concentration.
Definition
Depression (major depressive disorder) is a common mood condition marked by persistent sadness or loss of pleasure, along with physical and cognitive symptoms. It ranges from mild to severe. Screening tools like the PHQ-9 measure symptom severity; a clinician diagnoses depression after a full assessment.
What it can feel like
- Low mood or emptiness most of the day.
- Loss of interest in activities you used to enjoy.
- Changes in sleep or appetite.
- Fatigue, guilt, or difficulty concentrating.
Related screening tests on LuriaLab
- Escala Breve de Sintomas de Depressão (BDSC-I)
- Escalas de Depressão, Ansiedade e Estresse (DASS-21)
Related glossary terms
Perguntas frequentes
What PHQ-9 score indicates depression?
PHQ-9 scores range from 0 to 27, with bands from minimal to severe. Higher scores suggest more symptoms; a clinician interprets results in context.
Is depression the same as feeling sad?
No. Sadness is a normal emotion. Depression is persistent, affects many areas of life, and often includes physical and cognitive symptoms lasting two weeks or more.
When should I seek help for depression?
Consider professional support if low mood persists, affects daily functioning, or includes thoughts of self-harm. In a crisis, contact local emergency services or a crisis line.
Sources
- Kroenke K, Spitzer RL, Williams JBW. PHQ-9 validation
- WHO — depression fact sheet
Last reviewed: 2026-07-02. Screening tools on LuriaLab are for education only and do not provide a diagnosis.