ICD-11 vs DSM-5-TR: How Physicians Diagnose ADHD Today

Attention-Deficit/Hyperactivity Disorder (ADHD) is one of the most researched neurodevelopmental conditions, yet the two major diagnostic manuals the World Health Organization’s ICD-11 and the American Psychiatric Association’s DSM-5-TR approach its criteria in subtly different ways. Understanding these differences is essential for evidence-based diagnosis and for tailoring pharmacotherapy, including the decision to use non-stimulant agents such as atomoxetine.

1. Side-by-Side Diagnostic Criteria

Domain	ICD-11	DSM-5-TR
Symptom Count (Inattention / Hyperactivity-Impulsivity)	11 + 11 symptoms (no minimum count specified clinical judgment)	9 + 9 symptoms ≥6 (<18 yrs) or ≥5 (≥18 yrs)
Age-of-Onset Threshold	“Typically by early-mid childhood; evidence before 12”	Clear cutoff: several symptoms before age 12
Presentations / Specifiers	Predominantly Inattentive, Predominantly Hyperactive-Impulsive, Combined Course specifiers (e.g., partial remission) not defined	Same three presentations plus course specifier “partial remission”
Context & Impairment	Requires functional impact in ≥2 settings; qualitative description of “outside normal variation”	Requires impairment in ≥2 settings, supported by norm-referenced thresholds

2. Why the Differences Matter Clinically

The absence of explicit symptom thresholds in ICD-11 allows flexibility for cultural context and developmental stage, but it may introduce variability between clinicians. In contrast, DSM-5-TR’s quantified cut-offs facilitate research comparability and insurance authorization but risk overlooking clinically significant “sub-threshold” cases, especially in adults.

Research harmonization increasingly demands mapping tools that translate DSM-5-TR item counts into ICD-11’s broader descriptors.
Cross-cultural practice: Emerging evidence shows the ICD-11 framework improves sensitivity in regions where overt hyperactivity is less tolerated and thus under-reported.
Adult diagnosis: Lower symptom count in DSM-5-TR for adults (≥5) was retained to avoid false negatives, whereas ICD-11 relies on clinician judgment of impairment.

3. Choosing Atomoxetine Over Psychostimulants

Guidelines still position methylphenidate and amphetamine formulations as first-line pharmacotherapy. Nonetheless, atomoxetine a norepinephrine-reuptake inhibitor should be considered as initial or switch therapy in the following scenarios:

Tic or Tourette disorder stimulants can exacerbate motor/vocal tics.¹
Generalized anxiety, severe insomnia, or mood lability unresponsive to stimulant dose adjustments.¹
High cardiovascular risk (e.g., structural heart disease, arrhythmia, or family history of sudden cardiac death).²
Substance-use disorder or elevated diversion risk (incarcerated or collegiate settings).³
Inadequate response or intolerance after two stimulant trials at optimal doses.¹

Atomoxetine’s onset is slower (2–6 weeks), but its 24-hour coverage, minimal abuse liability, and persistence of effect overnight make it a valuable option for patients requiring continuous symptom control.

Expert Insight: “Think Beyond Stimulants”

Dr Léa Dubois, Child & Adolescent Psychiatrist, Paris (Hôpital Robert-Debré):

“In my clinic, nearly one in four new ADHD diagnoses meets at least two of the atomoxetine-first criteria above. Emphasizing cardiovascular screening and comorbidity mapping during assessment not only guides safer medication choices but also improves long-term adherence. With ICD-11’s broader descriptors, I find it crucial to systematize baseline rating scales and parent–teacher feedback before any pharmacologic decision.”

Considering atomoxetine? find out the current cost of Strattera (brand) and its generic options.

4. Rapid Diagnostic Checklist (DSM-5-TR-to-ICD-11)

Confirm ≥5 adult symptoms of inattention and/or hyperactivity-impulsivity lasting ≥6 months.
Verify onset before age 12 based on history and collateral reports.
Document functional impairment in at least two life domains (school, work, home).
Exclude alternative explanations (anxiety, mood, sleep, thyroid, substance use).
Reframe descriptive findings into ICD-11 narrative to aid cross-system coding.