Psychological Disorders
This domain tests your ability to recognise disorders from short symptom descriptions, place them in the DSM/ICD scheme, and explain causes through the biopsychosocial model.
What counts as abnormal
The four Ds: deviance from social norms, distress to self or others, dysfunction in daily life and danger. No single criterion is enough; a diagnosis needs a recognised pattern plus impairment.
Classification
DSM-5 (APA) and ICD-11 (WHO) list criteria; DSM-5 dropped the earlier five-axis structure. Classification improves communication and treatment choice but does not itself explain causes.
Major groups
- Anxiety: generalised anxiety disorder (excessive worry for six months or more), specific and social phobias, panic disorder, agoraphobia, and OCD (obsessions are intrusive thoughts; compulsions are repetitive acts that reduce anxiety).
- Mood: major depressive disorder (low mood or loss of interest with several other symptoms for two weeks), mania and bipolar disorder.
- Schizophrenia: positive symptoms (delusions, hallucinations, disorganised speech) and negative symptoms (flat affect, alogia, avolition). The dopamine hypothesis and the diathesis-stress model are the usual explanations.
- Personality disorders: cluster A (odd/eccentric), B (dramatic/emotional, including antisocial and borderline), C (anxious/fearful, including avoidant and dependent).
- Childhood: ADHD (inattention, hyperactivity, impulsivity), autism spectrum disorder (persistent deficits in social communication plus restricted, repetitive behaviour) and intellectual disability (low IQ with impaired adaptive functioning).
Causes
Biological (genes, neurotransmitters, brain damage), psychological (learning, cognitive style) and sociocultural (stress, poverty, family) factors combine in the biopsychosocial model.
Worked example
A person washes her hands for two hours a day after intrusive thoughts of contamination, knows the behaviour is excessive, and is distressed. Reasoning: the thoughts are obsessions, the washing is a compulsion and insight is preserved - obsessive-compulsive disorder, not a psychotic delusion.
Traps
Schizophrenia is not "split personality". Sadness after a loss is not automatically major depression. OCD is not obsessive-compulsive personality disorder. Naming a symptom is not the same as identifying its cause.