Educational Disclaimer: This case study is for educational and informational purposes only. It does not constitute medical advice, clinical guidance, or a substitute for professional psychiatric evaluation. All diagnostic criteria referenced are from the DSM-5-TR (APA, 2022). Clinical statistics cited are drawn from peer-reviewed literature and may vary across populations. Clinicians should rely on their professional training, direct patient assessment, and current evidence-based guidelines when making diagnostic and treatment decisions.

Clinical Vignette

Patient: "Mr. K," 28-year-old software engineer, self-referred after reading online about ADHD. He believes he has undiagnosed ADHD and requests stimulant medication.

Chief Complaint: "I can't concentrate at work. I'm constantly behind on deadlines and my mind races all day."

History of Present Illness: Mr. K reports difficulty sustaining attention during meetings and while reading technical documentation. He describes feeling restless, frequently shifting tasks without completing them, procrastinating on important projects, and forgetting to respond to emails. Symptoms have worsened significantly over the past 18 months, coinciding with a promotion to team lead. He reports difficulty falling asleep due to ruminating about the next day's responsibilities, frequent muscle tension (shoulders, jaw), and irritability with his partner. He checks his phone constantly for work messages and describes a persistent sense of dread about underperforming.

Developmental History: Mr. K reports being an "A/B student" through high school and college. He did not have behavioral referrals in childhood. His parents describe him as "a quiet kid who always did his homework." He graduated college on time with a computer science degree.

Substance Use: 3-4 cups of coffee daily. Occasional alcohol. Denies illicit substance use.

Medical History: No significant medical history. No current medications.

Family History: Mother has generalized anxiety disorder (treated with buspirone). Father has no psychiatric history.

Mental Status Exam: Alert, cooperative, mildly anxious. Psychomotor restlessness (fidgeting, leg bouncing). Speech normal rate. Thought process linear but tangential when discussing work stressors. No suicidal ideation. Insight partial; judgment intact.

Step 1: Identifying the Diagnostic Question

The core clinical question: Are Mr. K's concentration difficulties, restlessness, and executive dysfunction symptoms of ADHD, Generalized Anxiety Disorder, or a comorbid presentation?

This distinction carries significant treatment implications. ADHD is typically treated with stimulant medications, while GAD is treated with SSRIs/SNRIs, buspirone, or psychotherapy. Prescribing stimulants for primary anxiety can worsen the condition. Conversely, treating primary ADHD with SSRIs alone fails to address core executive dysfunction.

Step 2: ADHD Criterion Evaluation (DSM-5-TR)

Criterion A: Inattention Symptoms (6 of 9 required for adults, or 5 if age 17+)

Assessing the nine inattention symptoms:

  1. Fails to give close attention / makes careless mistakes — Reported ("behind on deadlines," missing emails). Possibly met. However, this must be distinguished from anxiety-driven cognitive overload.
  2. Difficulty sustaining attention — "Can't concentrate in meetings." Possibly met. Key question: Is the difficulty sustaining attention due to intrinsic attentional deficit or due to worry-based cognitive interference?
  3. Does not seem to listen when spoken to directly — Not clearly reported. Needs clarification.
  4. Fails to follow through on tasks — "Shifting tasks without completing them." Possibly met.
  5. Difficulty organizing tasks — Implied by procrastination and deadline issues. Possibly met.
  6. Avoids tasks requiring sustained mental effort — Procrastinates on technical documentation. Possibly met. However, anxiety-based avoidance (fear of failure) produces identical behavior.
  7. Loses things — Not reported. Not met.
  8. Easily distracted — Implied. Possibly met.
  9. Forgetful in daily activities — Forgetting to respond to emails. Possibly met.

Critical Distinction: Symptom Overlap

Six or more inattention symptoms appear "possibly met." However, every one of these symptoms has a plausible anxiety-based explanation. The clinical question is whether the symptoms represent a primary attentional deficit (ADHD) or secondary cognitive disruption caused by anxiety (pseudo-ADHD). The DSM-5-TR requires that symptoms "are not better explained by another mental disorder," including anxiety disorders.

Criterion B: Onset Before Age 12

Were several inattention or hyperactivity-impulsivity symptoms present prior to age 12?

Evidence Against: Mr. K was an A/B student through high school and college. No childhood behavioral referrals. Parents describe him as quiet and compliant. He completed college on time in a demanding major. This developmental history is inconsistent with childhood-onset ADHD that causes functional impairment. Criterion B is NOT convincingly met.

Criterion B is the most powerful differentiating criterion in this case. ADHD is a neurodevelopmental disorder with onset in childhood. While symptoms may go unrecognized until adulthood (particularly in the predominantly inattentive presentation), a history of strong academic performance without compensatory struggles argues against the diagnosis.

Additional ADHD Red Flags Not Present

  • No childhood history of losing belongings, forgetting homework, or difficulty with organization
  • No pattern of starting and abandoning hobbies across the lifespan
  • Symptoms have a clear temporal onset (18 months ago) rather than a lifelong pattern
  • Symptom onset coincides with an identifiable stressor (promotion)

Step 3: GAD Criterion Evaluation (DSM-5-TR)

Criterion A: Excessive anxiety and worry, occurring more days than not, for at least 6 months, about a number of events or activities.

Evidence: 18 months of persistent worry about work performance, dread about underperforming, rumination about responsibilities. Worry extends across multiple domains (work performance, relationships, meeting expectations). MET.

Criterion B: The individual finds it difficult to control the worry.

Evidence: Constant checking of phone for work messages. Difficulty falling asleep due to rumination. Worry persists despite adequate job performance. MET.

Criterion C: Three or more of six associated symptoms (for adults):

  1. Restlessness or feeling keyed up — Fidgeting, leg bouncing on MSE. "Constantly behind." MET.
  2. Being easily fatigued — Not directly reported but implied by sleep difficulty. Needs clarification.
  3. Difficulty concentrating or mind going blank — Core complaint. Concentration failure during meetings and reading. MET.
  4. Irritability — Irritable with partner. MET.
  5. Muscle tension — Shoulder and jaw tension. MET.
  6. Sleep disturbance — Difficulty falling asleep due to rumination. MET.

Five of six criteria met. Criterion C is MET.

Step 4: Distinguishing Anxiety-Driven vs. ADHD-Driven Concentration Difficulties

Feature Favors ADHD Favors GAD This Patient
Onset Childhood (before age 12) Any age; often tied to stressors GAD — onset at 26, linked to promotion
Academic history Inconsistent performance, underachievement relative to ability Adequate or strong performance GAD — A/B student, on-time graduation
Nature of distraction All stimuli equally distracting Distracted specifically by worry content GAD — mind races about work responsibilities
Restlessness quality Internal drive to move; desire for stimulation Nervous energy; tension-related GAD — muscle tension, jaw clenching
Task avoidance motivation Boredom; preference for novel stimulation Fear of failure; perfectionism GAD — dread about underperforming
Sleep pattern Difficulty due to hyperactive mind (diverse topics) Difficulty due to worry about specific concerns GAD — ruminates about next day's responsibilities
Hyperfocus capability Often present for high-interest tasks Less characteristic Not assessed
Family history ADHD: high heritability Anxiety disorders in first-degree relatives GAD — mother has GAD

Differential Analysis Summary

Seven of eight distinguishing features favor GAD over ADHD. The temporal onset, developmental history, nature of cognitive disruption, and family history converge on primary anxiety. The "ADHD symptoms" are better understood as secondary cognitive effects of chronic worry and arousal rather than a primary attentional deficit.

Diagnostic Formulation

Primary Diagnostic Consideration

Generalized Anxiety Disorder (F41.1)

All DSM-5-TR criteria are met. The concentration difficulties, restlessness, and executive dysfunction are best explained as downstream effects of chronic anxiety rather than a primary neurodevelopmental attentional deficit. The absence of childhood symptoms (Criterion B for ADHD) is the single most powerful piece of differentiating evidence.

Recommended Next Steps

  1. Psychoeducation: Explain the mechanism by which anxiety produces ADHD-like symptoms (cognitive load theory: working memory occupied by worry leaves insufficient capacity for task performance).
  2. Validated screening instruments: Administer the GAD-7 and the Adult ADHD Self-Report Scale (ASRS-v1.1) to quantify symptom severity.
  3. Obtain childhood records: If available, elementary school report cards or teacher comments can clarify developmental trajectory.
  4. Neuropsychological testing: If diagnostic uncertainty persists after clinical evaluation, formal testing (e.g., Continuous Performance Test, BRIEF-A) can help distinguish primary attentional deficits from anxiety-mediated cognitive disruption.
  5. Treatment trial: Initiate SSRI/SNRI and/or CBT for GAD. If concentration improves with anxiety treatment, this confirms the diagnostic formulation. If significant inattention persists after anxiety is adequately treated, reconsider comorbid ADHD.

Teaching Points

  • Adult ADHD self-referral rates have increased substantially, driven by social media content normalizing ADHD symptoms. The clinician must apply rigorous diagnostic criteria rather than accepting self-diagnosis.
  • DSM-5-TR Criterion B (onset before age 12) is the most powerful differentiating criterion between true ADHD and anxiety-driven pseudo-ADHD. Many adults presenting with "new-onset ADHD" have primary anxiety, depression, or sleep disorders.
  • Anxiety and ADHD CAN be comorbid (a substantial proportion of adults with ADHD also meet criteria for an anxiety disorder). Rule out the primary diagnosis first, treat it, and then reassess residual symptoms before adding a second diagnosis.
  • Caffeine consumption (3-4 cups daily in this case) can independently produce restlessness, concentration difficulty, and sleep disruption. This should be addressed as part of the treatment plan regardless of the primary diagnosis.
  • The directive to prescribe stimulants should be evaluated on diagnostic merit rather than patient request. Stimulants in primary anxiety can worsen restlessness, insomnia, and anxiety symptoms.