Psychological Disorders
Psychology · Section 4.3 · 18 study cards
Defining and classifying disorder, and the diagnostic features, causes and course of the major categories an introductory survey covers.
Practice this set → Spaced repetition, card by card. No account needed.
Method
Diagnosis is a sorting procedure, so practise it as one
Vignette questions dominate this unit. Work through them in a fixed order instead of matching on a single striking word.
- Check that the four Ds are met at all. Is there distress or dysfunction, and is the behaviour outside what the person's culture and situation would expect. If not, no diagnosis applies, and some items test exactly that.
- Read the duration. Two weeks points to major depression, two years to persistent depressive disorder, six months to generalised anxiety, one month after trauma to post-traumatic stress disorder, one week of elevated mood to mania. Duration alone settles many items.
- Identify the broad family. Mood, anxiety, obsessive-compulsive, trauma-related, psychotic, dissociative, personality, neurodevelopmental or somatic.
- Within the family, ask what the symptom is attached to. For anxiety, what is feared. For mood, what the highest mood state ever reached was. For psychosis, whether the symptoms are additions or reductions.
- Check age of onset and whether the pattern is episodic or lifelong. Lifelong and pervasive since adolescence suggests a personality disorder; early childhood and cross-situational suggests a neurodevelopmental one.
- Rule out the near neighbour and say why. Marks are given for the exclusion, not just the choice.
Hold the explanatory frameworks separately from the categories
For any disorder you should be able to give a biological account, a psychological account and a social-cultural one, and then combine them through diathesis-stress. Questions asking why one identical twin develops a condition and the other does not are always testing that model.
Keep description apart from explanation
The manual describes; the theories explain. Writing that someone has depression because they meet the criteria for depression is circular, and examiners penalise it.
Definitions and theorems
Worked example
A 21-year-old student is brought to a university clinic by a flatmate. Over the past seven months he has withdrawn from friends, stopped attending lectures and speaks little; when he does speak, sentences drift between unrelated topics. He reports hearing two voices commenting on his actions and believes the university has installed monitoring equipment in his room, a belief he holds despite the flatmate showing him there is none. He is not distressed by the voices themselves.
Identify the most likely category, classify each symptom, state what else you would need to know, and outline the current account of the causes.
Check the four Ds first. Functioning has collapsed across academic and social domains, so dysfunction is clearly met even though distress is limited, which is enough for a diagnosis to be considered.
Note the duration. Seven months of continuous disturbance rules out a brief psychotic episode and fits the requirement for a schizophrenia spectrum diagnosis, so record the timeline explicitly.
Classify the symptoms. Hearing voices is an auditory hallucination and the monitoring belief is a delusion, both positive symptoms. Withdrawal, reduced speech and loss of motivation are negative symptoms. The drifting speech is a disorganised symptom.
Rule out the near neighbours and say why. Major depression with psychotic features would require a sustained depressive syndrome, which is not described; a substance-induced psychosis and a medical cause must be excluded by history and examination, which is what you would ask for next.
Note the fit with the typical onset pattern: late adolescence to early twenties, gradual rather than acute onset, which is prognostically less favourable than a sudden onset following identifiable stress.
Give the causal account at three levels: genetic vulnerability, with risk near one per cent in the population and close to half in an identical twin of an affected person; neural findings including dopamine overactivity, disrupted glutamate signalling and enlarged ventricles; and environmental contributors including prenatal infection or malnutrition and later stress.
Close with the integration. Genes and prenatal events supply the diathesis, later stress supplies the trigger, and the fact that identical twins are discordant about half the time is the evidence that neither component alone is sufficient.
Common mistakes
- Reading positive symptoms as good ones. Positive means added to ordinary experience and negative means subtracted from it. Antipsychotic drugs treat the first far better than the second, so the mix-up damages treatment answers as well as description ones.
- Confusing obsessive-compulsive disorder with obsessive-compulsive personality disorder. The first is a cycle of intrusive thoughts and anxiety-reducing rituals experienced as unwanted. The second is a lifelong personality style of perfectionism, orderliness and control that the person usually regards as reasonable.
- Diagnosing bipolar disorder from the depression. The deciding feature is the highest mood state ever reached: a full manic episode gives bipolar I, hypomania with a depressive episode gives bipolar II, and neither gives a depressive disorder.
- Ignoring duration criteria. Two weeks, six months, one month after trauma, two years, one week of elevated mood. Many vignette questions are decided entirely by the timeline, and a correct-sounding answer that breaks it scores nothing.
- Treating a diagnostic label as an explanation. Saying that a person withdraws because they have schizophrenia is circular. The explanation comes from the biological, psychological and social accounts, brought together through diathesis-stress.
Practice it
Reading the method is not the same as being able to recall it under pressure. This set drills 18 cards one at a time and schedules each card separately, so the ones you keep missing come back sooner.