Anxiety disorders
Anxiety is a feeling of fear and worry with a racing heart, sweating and tight muscles. Some anxiety is normal. It becomes a disorder when it is too strong, lasts long and stops daily life.
- Generalised anxiety disorder: long, vague worry about many things, with restlessness and poor sleep.
- Panic disorder: sudden attacks of intense fear, chest pain, breathlessness and fear of dying or losing control.
- Phobias: strong, unreasonable fear of a thing or situation. Specific (e.g. dogs, heights), social (fear of being judged), and agoraphobia (fear of places where escape is hard).
- Separation anxiety disorder: a child (or adult) feels extreme fear when away from a parent or loved one.
Obsessive-compulsive and related disorders
Obsessions are unwanted thoughts that keep coming back (e.g. "My hands are dirty"). Compulsions are acts done again and again to reduce the worry (washing, checking, counting). The relief is short, so the loop repeats. Related: hoarding disorder (cannot throw things away), trichotillomania (hair pulling), excoriation (skin picking).
Trauma- and stressor-related disorders
Post-traumatic stress disorder (PTSD) can follow a shocking event like an accident, flood, violence or war. Signs: flashbacks (reliving it), nightmares, avoiding reminders, feeling numb, being easily startled and always alert. Other forms: acute stress disorder and adjustment disorders.
Somatic symptom and related disorders
Soma means body. Here the person has body complaints without a full medical cause.
- Somatic symptom disorder: much worry about body symptoms like pain or tiredness.
- Illness anxiety disorder: constant fear of having a serious illness, even after normal tests.
- Conversion disorder: loss of a body function (e.g. sudden paralysis, blindness) with no physical cause, often after stress.
Dissociative disorders
Dissociation means a split between thoughts, memory and sense of self.
- Dissociative amnesia: cannot recall important personal facts, usually after stress. In dissociative fugue the person also travels away and may take a new identity.
- Dissociative identity disorder (earlier "multiple personality"): two or more distinct identities in one person, often linked to severe childhood abuse.
- Depersonalisation/derealisation: feeling unreal, like watching yourself or the world from outside.
Depressive disorder
Major depressive disorder: for at least two weeks, low mood or loss of interest nearly every day, plus changes in sleep, appetite and weight, tiredness, slow thinking, feelings of guilt or worthlessness, and thoughts of death. Risk factors: genes, age, gender (more common in women), stressful life events and low social support. Suicide is a serious risk: warning signs include talk of death, giving away things and withdrawal. Always tell a trusted adult and get help.
Bipolar and related disorders
Mood swings between two poles. Mania: very high or irritable mood, little need for sleep, racing ideas, big plans, risky spending. Depression: the low pole. Bipolar I has full mania; cyclothymic disorder is a milder, long-lasting swing. It was earlier called manic-depressive disorder.
Schizophrenia spectrum and other psychotic disorders
Schizophrenia means a break from reality in thinking, perception and emotion. It does NOT mean "split personality".
- Positive symptoms (added): delusions (firm false beliefs: of persecution, of grandeur, of reference, of control), hallucinations (seeing or hearing things that are not there; hearing voices is most common), and disorganised thinking and speech (derailment, loosening of associations, made-up words).
- Negative symptoms (taken away): flat or blunted emotion, alogia (poverty of speech), avolition (no drive to act), social withdrawal.
- Psychomotor symptoms: odd, stiff or frozen postures (catatonia).
Neurodevelopmental disorders
These begin in early childhood as the brain develops.
- ADHD (attention-deficit/hyperactivity disorder): inattention (cannot focus, loses things) and/or hyperactivity-impulsivity (cannot sit still, blurts out).
- Autism spectrum disorder: difficulty with social communication and relationships, and repeated behaviours or narrow interests.
- Intellectual disability: IQ roughly below 70 plus difficulty in daily-life (adaptive) skills, starting before age 18.
- Specific learning disorder: difficulty in reading (dyslexia), writing or maths despite normal intelligence.
Disruptive, impulse-control and conduct disorders
- Oppositional defiant disorder (ODD): an angry, arguing, defiant child who refuses rules and blames others, but is not usually cruel.
- Conduct disorder: repeatedly breaking others' rights and major rules: bullying, fighting, cruelty to people or animals, stealing, destroying property.
Feeding and eating disorders
- Anorexia nervosa: sees self as fat even when very thin; eats very little; fears gaining weight.
- Bulimia nervosa: eats a very large amount (binge), then gets rid of it by vomiting, laxatives or over-exercise.
- Binge-eating disorder: frequent binges without purging, with loss of control.
Substance-related and addictive disorders
Harmful use of alcohol, tobacco, cannabis, heroin, cocaine and similar substances. Key ideas: substance abuse (harmful repeated use), dependence (craving and compulsive use), tolerance (needing more for the same effect) and withdrawal (unpleasant signs when stopping). Alcohol harms the liver and brain; heroin slows breathing; cocaine over-excites the heart. Gambling disorder is also an addictive disorder.
Try it
In the 3D free play, tap each family. For each, write one sign you could notice in a friend and one kind thing you could do (listen, stay with them, tell a trusted adult, suggest a counsellor). Remember: you notice, you do not diagnose. Only trained experts diagnose.
Key formulas and definitions
- Obsession = unwanted repeating thought; Compulsion = repeated act to reduce worry
- Depression: low mood/loss of interest ≥ 2 weeks
- Bipolar = mania ⇄ depression
- Schizophrenia: positive (added) vs negative (taken away) symptoms
- Substance: tolerance (need more) · withdrawal (signs on stopping)
Worked examples
1. Karan checks the door lock 20 times before sleeping and cannot rest until he does. Which disorder family?
Obsessive-compulsive disorder: the obsession is "the door may be open"; the compulsion is checking again and again for short relief.
2. Two months after a bus accident, Sana has nightmares, avoids buses and jumps at loud sounds. Which disorder?
Post-traumatic stress disorder (PTSD): flashbacks/nightmares, avoidance and high alertness after a trauma.
3. Rahul believes TV newsreaders send him secret messages and hears voices commenting on him. Name the symptoms.
Delusion of reference (false belief that events refer to him) and auditory hallucination. Both are positive symptoms of schizophrenia.
4. For two weeks Anu hardly sleeps, talks very fast, plans to start five companies and spends all her savings. Earlier she had weeks of deep sadness. Which disorder?
Bipolar disorder: a manic episode now, after a depressive episode earlier.
5. A bright 9-year-old reads "b" as "d", reads slowly and hates reading aloud, though he is good at maths. What might this be?
Specific learning disorder with difficulty in reading (dyslexia), a neurodevelopmental disorder. Intelligence is normal.
6. Vikram needs more and more alcohol to feel the same effect, and shakes and sweats when he stops. Name the two signs.
Tolerance (needs more) and withdrawal (shaking, sweating on stopping): signs of alcohol dependence.
Common mistakes
- Saying schizophrenia means "split personality". That is dissociative identity disorder.
- Mixing obsessions (thoughts) with compulsions (acts).
- Calling every sad day "depression". Depression lasts at least two weeks and disturbs life.
- Thinking ADHD or autism is caused by bad parenting. They are neurodevelopmental.