Disruptive mood dysregulation disorder — formative SAQs

SAQ 1 (10 marks)

An eight-year-old boy has severe temper outbursts three to four times a week at home and at school, grossly out of proportion to the trigger, and is described by both parents and teachers as "always angry, easily annoyed, and grouchy most of the day, every day." This pattern has been present for fourteen months with no clear break, began around age six, and is disrupting his learning and friendships. There is no history of distinct elevated-mood episodes, no sleep reduction, no psychosis, and no disclosed abuse. ^{[1] [2]}

1. Give the most likely diagnosis with the criteria that support it, and state the most important condition to exclude before labelling it. (4) ^[1]
2. List three differential diagnoses with a discriminator for each. (3) ^[2]
3. Outline the first-line management plan and explain why medication is not the routine first step. (3) ^[4]

Model answer — SAQ 1

(1) Diagnosis and the must-exclude condition (4). The picture fits disruptive mood dysregulation disorder (DMDD): severe, recurrent temper outbursts grossly out of proportion and inconsistent with developmental level, occurring at least three times a week; a chronic, irritable or angry mood most of the day, nearly every day; onset before age ten; duration at least twelve months with no symptom-free stretch over three months; present in two or more settings (home and school) and impairing. The single most important condition to exclude before labelling it is paediatric bipolar disorder — ask explicitly for any distinct period of elevated or expansive mood with decreased need for sleep, racing thoughts and grandiosity. ^{[1] [3]}

(2) Differentials with discriminators (3). ODD: a pattern of angry/irritable mood plus argumentative, defiant or vindictive behaviour, but without the severe frequent outbursts and chronic sustained baseline of DMDD; if both criteria are met, assign DMDD only. ADHD: chronic inattention, hyperactivity and impulsivity with secondary frustration, but irritability is not the sustained core. Intermittent explosive disorder: discrete outbursts without the chronic between-outburst baseline irritability, and mutually exclusive with DMDD. A comorbid depressive or anxiety disorder and an organic or substance cause should also be considered. ^[2]

(3) First-line management and why not medication first (3). First-line is structured parent training (PCIT, Triple P, Coping Power) plus child emotion-regulation CBT, with a school-based behaviour plan and psychoeducation. Medication is not the routine first step because the meta-analytic evidence shows the most consistent benefit for psychosocial interventions, while drugs carry smaller, less consistent effects and side-effect burdens; drugs are adjunctive and target a comorbidity (ADHD, depression, anxiety) or short-term dangerous aggression. ^[4]