Understanding Depression: From Clinical Definitions to Treatment Approaches

Depression is a serious mood disorder that affects the way a person thinks, feels, and behaves. It goes beyond ordinary sadness and can significantly impair daily functioning. Understanding depression from a clinical perspective helps reduce stigma and promotes early intervention.

What Is Depression? — Clinical Definition

According to clinical and diagnostic frameworks like the DSM-5 and ICD-11, Major Depressive Disorder (MDD) is characterized by:

Persistent low mood or sadness
Loss of interest or pleasure in activities (anhedonia)
Changes in sleep (insomnia or hypersomnia)
Changes in appetite or weight
Fatigue or loss of energy
Feelings of worthlessness or guilt
Poor concentration or indecisiveness
Recurrent thoughts of death or suicide

Important: Symptoms must last for at least 2 weeks and significantly impact daily functioning to meet the criteria for clinical depression.

Types of Depression

Major Depressive Disorder (MDD): Persistent, intense depressive symptoms.
Persistent Depressive Disorder (Dysthymia): Long-lasting low mood for 2+ years.
Bipolar Depression: Depressive episodes within Bipolar I or II Disorder.
Seasonal Affective Disorder (SAD): Depression linked to seasonal changes.
Postpartum Depression: Depression following childbirth.
Atypical Depression: Mood reactivity present, with increased appetite or sleep.

Causes of Depression — A Biopsychosocial Perspective

1. Biological Factors

Genetic vulnerability
Neurochemical imbalances (serotonin, norepinephrine, dopamine)
Hormonal changes
Brain structure differences

2. Psychological Factors

Negative thinking patterns
Low self-esteem
Childhood trauma or unresolved grief
Maladaptive coping mechanisms

3. Social Factors

Stressful life events
Loneliness or social isolation
Workplace or relationship pressures
Financial stress

Signs and Symptoms

Depression affects multiple areas of life, and symptoms may be: Emotional, cognitive, physical, or behavioral.

Emotional Symptoms

Intense sadness
Loss of pleasure
Irritability

Cognitive Symptoms

Hopelessness
Difficulty concentrating
Persistent self-criticism

Physical Symptoms

Unexplained aches and pains
Sleep disturbances
Low energy

Behavioral Symptoms

Social withdrawal
Reduced productivity
Neglecting responsibilities

Diagnosis of Depression

A mental health professional uses structured interviews, rating scales, and medical evaluations to diagnose depression. The clinician assesses:

Duration of symptoms
Severity and impact on functioning
Risk factors such as suicidal thoughts
Medical conditions or medications that may contribute

Treatment Approaches for Depression

1. Psychotherapy

Cognitive