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9990 · 1.3.1

Diagnostic criteria for impulse control disorders — practice questions

Practice and worked examples for 9990 Diagnostic criteria for impulse control disorders. Short previews only — attempt the full question in MarkScheme against the official scheme.

Worked example 1

A shop assistant repeatedly steals small items they do not need. Before each theft they feel mounting tension; afterwards they feel relieved. They feel guilty but cannot stop.

(a) Outline diagnostic criteria for kleptomania and explain why this case may fit. [4 marks] (b) Evaluate the validity of impulse control disorders as a separate diagnostic category. [6 marks]

Show solution outline

(a) AO1 — Kleptomania criteria applied:

  • Recurrent failure to resist stealing — pattern described.
  • Items not needed for use or value — small unnecessary items.
  • Not explained by anger, revenge, or psychosis.
  • Tension before, relief/pleasure after — classic tension–release cycle.
  • Causes distress and impaired control — guilt and inability to stop.

(b) AO3 — Validity evaluation:

  • Strengths: Captures distinct motivational profile (urge + relief) different from planned theft (conduct) or OCD rituals.
  • Limitations — rarity: True kleptomania is rare — most shoplifting is criminal, not clinical; category may be over-applied in forensic settings.
  • Comorbidity: High overlap with depression, OCD, substance use — suggests shared underlying impulsivity dimension rather than discrete disorders.
  • DSM-5 changes: Some ICDs moved (e.g. gambling to substance-related) — reflects instability of construct.

Judgement: Category has face validity for tension–release impulse patterns but questionable reliability in practice due to overlap with other disorders and low base rates.

Worked example 2

A psychologist assesses 'Patient C', a 22-year-old, for suspected pyromania over a 4-week period using the 'Pyromania Symptom Severity Scale' (PSSS), where a score over 15 indicates significant symptoms. The weekly scores were recorded as follows:

  • Week 1: 18
  • Week 2: 21
  • Week 3: 16
  • Week 4: 19

(a) Calculate the patient's mean PSSS score over the 4-week assessment period. [2 marks] (b) Based on the data and the diagnostic criteria, justify a potential diagnosis of pyromania. [4 marks]

Show solution outline

(a) Calculation of Mean PSSS Score:

  • Step 1: Sum the weekly scores. 18 + 21 + 16 + 19 = 74
  • Step 2: Divide the total sum by the number of weeks. 74 / 4 weeks = 18.5
  • Final Answer: The patient's mean PSSS score is 18.5. [2 marks]

(b) Justification for Pyromania Diagnosis:

  • AO2 Application: The mean score of 18.5 is above the clinically significant threshold of 15, suggesting a persistent and severe symptom pattern. This supports the diagnosis.
  • Criterion 1: Deliberate and purposeful fire setting on more than one occasion. The assessment spans 4 weeks, implying recurrent behaviour, which would need to be confirmed in the full diagnostic interview.
  • Criterion 2: Tension or affective arousal before the act. The high PSSS scores (e.g., 21 in Week 2) are designed to quantify this tension and the urge to set fires. The consistently high scores reflect this part of the diagnostic cycle.
  • Criterion 3: Pleasure, gratification, or relief when setting fires or witnessing the aftermath. The PSSS scale would include items measuring this relief. The scores suggest the behaviour is reinforcing, fitting this criterion.
  • Exclusionary Criteria: A full diagnosis would also require ruling out other motives (e.g., monetary gain, revenge, political protest) and ensuring the behaviour is not better explained by a manic episode or conduct disorder. The scenario implies a focus on psychological symptoms, consistent with pyromania rather than arson. [4 marks]
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