Depression: Symptoms, Causes, and Treatment

Depression is more than just feeling down or having a bad day. It's a serious mood disorder that affects how you think, feel, and handle daily activities. According to WHO, depression is a leading cause of disability worldwide, affecting about 5% of adults. The NIMH notes it involves persistent sadness, loss of interest, and interferes with daily functioning for at least two weeks.

In plain words

Depression is more than feeling sad. It is a serious mood disorder that affects how you think, feel, and handle daily tasks. It can last for weeks or longer and makes it hard to enjoy life. Depression is a leading cause of disability worldwide. Symptoms include persistent sadness, loss of interest in activities, and trouble with daily functioning. It is not just a bad day. It needs medical attention.

What is Depression: Symptoms, Causes, and Treatment?

Symptoms

Early symptoms

Persistent sadness or anxiety: Feeling sad or anxious most of the time, even without a clear reason. (1) (4)
Feelings of hopelessness: A sense that things will never get better or that nothing will make you feel happy again. (1)
Loss of interest in hobbies: Not enjoying activities or hobbies that you used to find pleasurable. (4)
Fatigue and low energy: Feeling tired all the time, even after a full night's sleep. (1)

Serious or emergency symptoms

Thoughts of death or suicide: Thinking about death or suicide, or making plans for self-harm. Seek immediate professional help or call emergency services. (8)
Sudden mood changes: Abrupt shifts in mood or behavior that seem out of character. Consult a healthcare provider immediately. (4)

Causes

Primary causes

Genetic factors: Having a family history of depression can increase your risk. (1)
Brain chemistry: Imbalances in brain chemicals like serotonin and dopamine can contribute to depression. (1)
Stressful life events: Trauma, loss, or major life changes can trigger depressive episodes. (1)

Risk factors

Chronic illness

Conditions like heart disease, diabetes, or cancer can increase the risk of depression. (6)

Substance abuse

Alcohol or drug abuse can lead to or worsen depression. (3)

Diagnosis

Diagnosis involves medical history, physical exam, and possibly lab tests to rule out other conditions. Mental health professionals use DSM-5 criteria—presence of five or more specified symptoms lasting two weeks. Screening tools like the PHQ-9 help assess symptom severity.

Clinical interview

To assess symptoms, duration, and their impact on daily life. (7)

PHQ-9 screening tool

A questionnaire used to assess the severity of depressive symptoms. (7)

Treatment

Medication options

Antidepressants

These medications help balance brain chemicals that influence mood and emotions. (2) (5)

Brain stimulation therapies

Used for treatment-resistant depression, these therapies stimulate specific areas of the brain. (2)

Lifestyle and self-care

Maintain a routine: Establishing a daily routine can help provide structure and a sense of normalcy. (2)
Exercise regularly: Physical activity can help improve mood and reduce symptoms of depression. (2)
Avoid alcohol: Alcohol can worsen depression and interfere with treatment. (2)

Always discuss dosing and treatment changes with your own prescriber.

Possible complications

Worsening symptoms: Untreated depression can lead to more severe symptoms and longer episodes. (6)
Substance abuse: Depression increases the risk of alcohol or drug abuse as a way to self-medicate. (3)

When to see a doctor

Routine follow-up

Seek professional consultation if symptoms persist for more than two weeks. (7)

Seek emergency care

Immediate care is required if there are thoughts of suicide or self-harm. (8)

Frequently asked questions

What's the difference between sadness and depression?

Sadness is temporary and tied to specific situations, while depression persists for weeks or longer, often without clear cause, and impairs daily functioning. Depression involves clusters of symptoms like sleep/appetite changes and loss of pleasure that aren't typical of ordinary sadness (NIMH). (1)

Can depression go away on its own?

Mild cases might improve without formal treatment (NHS), but moderate-severe depression usually requires professional intervention. Untreated episodes may last months to years and increase recurrence risk (WHO). Early treatment improves recovery chances. (4) (6)

Are antidepressants addictive?

SSRIs/SNRIs aren't addictive but shouldn't be stopped abruptly—tapering under medical supervision prevents discontinuation symptoms. NIMH notes they don't create a 'high' or craving associated with substance addiction, though some may experience withdrawal effects. (2)

Do children get depression?

Yes—childhood depression (though symptoms may differ from adults) is recognized. Irritability often predominates over sadness. NIMH data shows about 4% of US children aged 3-17 have diagnosed depression, though actual rates may be higher. (1)

How long does treatment take?

NHS guidelines note antidepressants typically take 2-4 weeks to start working (full effect in 6-8 weeks). Psychotherapy duration varies, often 6-12 sessions for mild-moderate cases. Maintenance treatment may continue months after symptom relief to prevent relapse. (5)