Is mental illness different from ordinary sadness or worry?

Usually yes. Mental illness is more severe, lasts longer, and more strongly impairs coping with everyday life.

How do doctors diagnose mental illness?

By talking with the person (and often family), assessing how severe, how long, and how much symptoms affect function. There is no single blood test that confirms most mental illnesses.

Can someone live well with mental illness?

Yes. Treatment, social support, and community care help many people live productively. Access to care and stigma remain major barriers.

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Mental Health

Overview of mental illness

Also known as: Mental disorders, Psychiatric illness, Mental health conditions

Overview of mental illness condition guide: symptoms, causes, prevention, and when to seek care. Educational only — not a diagnosis.

Overview

Mental illness covers a wide range of problems with thinking, mood, and/or behaviour. Everyone has unsettling thoughts or strong feelings at times, but with mental illness these happen often enough or intensely enough to disrupt work, relationships, or self-care. It may be short- or long-term. Common groups include anxiety, depression and other mood disorders, schizophrenia, personality disorders, eating disorders, PTSD, and suicidal thinking. Nearly half of adults experience mental-illness symptoms at some point—depression is among the most common. Stigma still stops people seeking help; mental illness is not laziness or a personal choice.

Symptoms

Big personality or behaviour changes without a clear reason
Confusion and poor concentration
Disorganised thoughts or confusing answers
Inappropriate behaviour in ordinary settings
Seeing or hearing things that are not there
Fixed false beliefs despite strong evidence
Excessive suspicion, deep sadness, or ongoing anxiety

Causes

It usually comes from an interplay of genetics, biological factors (including brain chemistry), life stress, environment and culture, and medical conditions that affect the brain. Job loss, divorce, or substance misuse raise risk. Birth complications or brain infections can increase later risk. It is not the fault of the person affected.

Treatment (general information)

Main treatments are medicines and talking therapy (counselling); for many conditions combining both works better than either alone. Family, friends, and support groups can help. Today most people are treated in the community rather than long-term institutions. See also treatment of mental illness for more detail.

Prevention

There is no perfect prevention, but social support, managing stress, avoiding substance misuse, treating physical illness early, and seeking help promptly reduce harm. Reducing stigma makes it easier for people to get care.

When to see a doctor

Seek help if symptoms persist, worsen, or block work and relationships. Get emergency help for thoughts or attempts of self-harm, harming others, severe confusion, or new hallucinations/delusions.

Frequently asked questions

Is mental illness different from ordinary sadness or worry?: Usually yes. Mental illness is more severe, lasts longer, and more strongly impairs coping with everyday life.
How do doctors diagnose mental illness?: By talking with the person (and often family), assessing how severe, how long, and how much symptoms affect function. There is no single blood test that confirms most mental illnesses.
Can someone live well with mental illness?: Yes. Treatment, social support, and community care help many people live productively. Access to care and stigma remain major barriers.