Depression is a common mental health disorder that affects how a person feels, thinks, and functions. It goes beyond everyday sadness. It’s a persistent feeling of emptiness, hopelessness, or a lack of interest in life that can last for weeks, months, or even longer.

Key features of depression:
To be diagnosed with major depressive disorder (MDD), symptoms typically last at least 2 weeks and cause noticeable problems in daily life.

Emotional symptoms:
Deep sadness or hopelessness
Loss of interest or pleasure in activities once enjoyed
Feelings of worthlessness or excessive guilt
Irritability or frustration, even over small things
Thoughts of death or suicide

Physical and cognitive symptoms:

Fatigue or low energy
Trouble sleeping (insomnia or oversleeping)
Changes in appetite or weight
Difficulty concentrating, thinking, or making decisions
Slowed speech or movements

Types of depression:
Major Depressive Disorder (MDD): most common, symptoms last weeks or longer
Persistent Depressive Disorder (Dysthymia): chronic low mood lasting 2+ years
Postpartum Depression: occurs after childbirth
Seasonal Affective Disorder (SAD): related to seasonal changes, often winter
Bipolar Depression: depressive episodes as part of bipolar disorder

Causes and risk factors:

Biological: brain chemistry, hormone changes, genetics
Psychological: trauma, abuse, low self-esteem
Environmental: chronic stress, isolation, financial issues
Medical: chronic illness, certain medications