What assessments are used to diagnose attention-deficit/hyperactivity disorder in adults?

Diagnosing ADHD in Adults

Adults with suspected ADHD require a comprehensive clinical interview documenting childhood symptom onset before age 12, combined with validated rating scales (particularly the Adult ADHD Self-Report Scale), collateral informant reports, and systematic screening for mimicking conditions and comorbidities. 1, 2

Core Diagnostic Components

Clinical Interview Requirements

The diagnostic evaluation must establish three essential elements through direct interview: 1, 3

• Childhood onset documentation – Confirm that ADHD symptoms were present before age 12 years, as mandated by DSM-5 criteria, using retrospective recall from the patient and ideally corroborated by parents, siblings, or childhood records 1, 2

• Current symptom assessment – Document at least 5 symptoms of inattention and/or hyperactivity-impulsivity that have persisted for at least 6 months in the adult presentation 1

• Cross-situational impairment – Verify that symptoms cause functional impairment in at least 2 settings (work, home, social relationships), as this multi-setting requirement distinguishes ADHD from situational problems 1, 3

Validated Rating Scales

The Adult ADHD Self-Report Scale (ASRS-V1.1) is the primary screening tool recommended for adult ADHD evaluation. 1, 4

• The ASRS-V1.1 screens positive when the patient endorses "often" or "very often" for 4 or more of 6 questions on the short screener 1, 4

• The full ASRS was updated in 2017 to reflect DSM-5 criteria and includes executive functioning deficits that characterize adult ADHD beyond the DSM symptoms 4

• The Wender Utah Rating Scale assesses retrospective childhood symptoms and can supplement the clinical interview 1, 5

• The Conners Adult ADHD Rating Scales (CAARS) provide comprehensive symptom and functional assessment from both patient and observer perspectives 2, 5

Collateral Information

Gathering information from multiple informants is essential, not optional, for adult ADHD diagnosis. 1, 5, 3

• Obtain reports from spouses, partners, parents, or close friends who can describe the patient's behavior across different settings 1, 5

• Collateral sources help verify childhood symptom onset and current functional impairment, addressing the limitation that adults may have poor insight into their own symptoms 5, 3

Medical Screening

A focused medical assessment must rule out conditions that mimic ADHD symptoms: 1

• Thyroid disorders – Hyperthyroidism can present with restlessness, distractibility, and emotional lability 1

• Sleep disorders – Sleep apnea, insufficient sleep, and circadian rhythm disorders frequently mimic inattention and executive dysfunction 1

• Neurological conditions – Seizure disorders, traumatic brain injury, and other neurological conditions should be considered 1

• Consider screening laboratory tests including thyroid function tests and basic metabolic panel when clinically indicated 1

Differential Diagnosis and Comorbidity Screening

Systematic evaluation for overlapping psychiatric conditions is critical because symptom overlap is substantial and comorbidity rates are high. 1, 2, 5

Conditions That Mimic ADHD

• Mood disorders – Bipolar disorder (especially during hypomanic episodes) and major depression can present with distractibility, restlessness, and executive dysfunction 1, 2

• Anxiety disorders – Generalized anxiety, social phobia, and PTSD frequently cause concentration difficulties and restlessness that resemble ADHD 1, 2, 5

• Substance use disorders – Active substance use or withdrawal can produce inattention, impulsivity, and mood instability; chronic use may cause persistent cognitive deficits 1, 2, 5

• Personality disorders – Borderline and antisocial personality disorders share features of impulsivity and emotional dysregulation with ADHD 1, 5

Common Comorbidities

The majority of adults with ADHD meet criteria for at least one other psychiatric disorder: 5

• Anxiety disorders and mood disorders are the most frequent comorbidities 1, 2

• Substance use disorders occur at elevated rates in adults with ADHD 1, 2, 5

• These comorbid conditions may require treatment before or concurrent with ADHD treatment 1

Diagnostic Algorithm

Follow this step-by-step approach: 1

1. Initial screening – Administer the ASRS-V1.1 screener to patients presenting with concentration difficulties, disorganization, or impulsivity 1, 4

2. Comprehensive clinical interview – When screening is positive, conduct a detailed interview covering childhood onset, current symptoms, and functional impairment across multiple settings 1, 3

3. Collateral information – Obtain reports from family members or close contacts to corroborate symptom history and current impairment 1, 5

4. Structured rating scales – Complete full ASRS and consider CAARS or Wender Utah Rating Scale for comprehensive symptom assessment 1, 2

5. Comorbidity screening – Systematically evaluate for mood disorders, anxiety disorders, substance use disorders, and personality disorders 1, 2

6. Medical screening – Rule out thyroid disorders, sleep disorders, and neurological conditions through history, examination, and targeted laboratory testing 1

7. Functional impairment assessment – Document specific examples of impairment in work performance, relationships, and daily functioning 1, 3

Common Diagnostic Pitfalls

• Relying solely on patient self-report without collateral information leads to diagnostic errors because adults often lack insight into their symptoms or may minimize impairment 5, 3

• Failing to document childhood onset before age 12 violates DSM-5 criteria; adult-onset "ADHD" symptoms usually represent another condition 1, 2

• Missing comorbid conditions that require treatment, particularly mood and anxiety disorders that may worsen with stimulant therapy 1, 2

• Overlooking substance use as either a cause of symptoms or a comorbidity that complicates treatment 1, 2, 5

• Diagnosing ADHD when symptoms occur in only one setting (e.g., only at work) suggests situational stress rather than ADHD 3

When to Refer

Refer to psychiatry or psychology when: 1

• Diagnostic uncertainty persists after comprehensive primary care evaluation 1

• Complex comorbid psychiatric conditions are present that exceed primary care scope 1

• Specialized neuropsychological testing is needed to clarify cognitive deficits or learning disabilities 1

• Treatment resistance occurs or specialized psychotherapy is required 1