What is the appropriate initial evaluation and workup for a 22‑year‑old with new or worsening difficulty concentrating?

Initial Workup for a 22-Year-Old with Difficulty Concentrating

Begin with a targeted medical history focusing on onset, duration, and associated symptoms, followed by laboratory screening for reversible metabolic and endocrine causes, then proceed to psychiatric evaluation if medical causes are excluded. 1, 2

Step 1: Focused History and Collateral Information

• Establish timeline: Determine whether concentration difficulty is acute (days to weeks), subacute (weeks to months), or chronic, as acute onset raises concern for medical causes including metabolic disturbances, infections, or toxin exposure 1, 2
• Obtain collateral history from family members or close contacts to establish baseline functioning and identify changes in emotions, thinking, behavior, sleep patterns, and overall daily functioning that the patient may not recognize or report accurately 3
• Screen for substance use: Ask specifically about marijuana, alcohol, caffeine, and other psychoactive substances, as illicit drug use is the most common medical cause of acute psychiatric symptoms 2, 4
• Assess for head trauma, seizures, or new headaches: Recent head injury, loss of consciousness, or worsening headaches suggest intracranial pathology requiring urgent evaluation 1, 2

Step 2: Targeted Physical and Mental Status Examination

• Vital signs: Check for tachycardia or severe hypertension (suggesting drug toxicity or thyrotoxicosis) and fever (suggesting encephalitis or infection) 2
• Complete neurologic examination: Look for focal deficits, abnormal deep tendon reflexes, muscle weakness, or changes in muscle tone that would indicate central nervous system pathology 1, 2
• Mental status assessment: Evaluate orientation, memory, attention span, and executive function; note whether the patient exhibits cognitive changes, disorganized speech, or altered level of consciousness 1, 4

Step 3: Initial Laboratory Screening

Order the following first-tier tests to identify reversible causes: 1, 2, 4

• Complete blood count with differential
• Comprehensive metabolic panel (electrolytes, glucose, creatinine, liver function)
• Thyroid-stimulating hormone (TSH)
• Calcium (pH-corrected ionized calcium preferred) and magnesium
• Vitamin B12, folate, and niacin levels
• Urine toxicology screen
• Consider HIV and syphilis testing based on risk factors

Common pitfall: Do not routinely order extensive laboratory panels in patients with known psychiatric disease presenting with symptom exacerbation unless history or examination suggests a medical cause 4

Step 4: Psychiatric Symptom Screening

If medical causes are excluded or unlikely, systematically screen for major psychiatric disorders using a structured approach: 5

Depression

• "Over the past 2 weeks, have you felt down, depressed, or hopeless most of the day, nearly every day?" 5
• If positive: Assess for sleep changes, energy level, appetite changes, concentration difficulty, feelings of worthlessness, and suicidal ideation 3, 5

Anxiety Disorders

• "Do you worry excessively about multiple things, finding it difficult to control the worry?" 5
• If positive: Assess for restlessness, fatigue, difficulty concentrating, irritability, muscle tension, and sleep disturbance 5

Attention Deficit Disorder

• "Have you had lifelong difficulty sustaining attention, organizing tasks, or completing projects?" 5
• Note: Adult ADHD typically has childhood onset; new-onset concentration problems at age 22 are more likely due to other causes 5

Psychotic Symptoms

• "Have you experienced things that others don't see or hear?" or "Do you have beliefs that others find unusual or hard to understand?" 2, 5
• Key distinction: Auditory hallucinations and complicated delusions suggest primary psychiatric disorder, while visual hallucinations and cognitive changes suggest medical causes 2

Step 5: Additional Testing Based on Initial Findings

If neurologic signs or unexplained cognitive changes are present:

• Brain imaging (CT or MRI): Obtain when initial evaluation raises concern for intracranial pathology or does not identify a clear cause 1
• Electroencephalography (EEG): Consider if seizure activity is suspected based on episodic symptoms, brief behavioral arrest, or transient confusion 1

If psychiatric disorder is suspected:

• Structured cognitive screening: Use Montreal Cognitive Assessment (MoCA) to detect subtle cognitive impairment that may not be apparent on routine mental status examination 3
• Informant-based tools: Consider Everyday Cognition scale (ECog) or AD8 to capture informant's report of cognitive and functional changes 3

Critical Caveats

• Do not attribute concentration difficulty solely to stress or psychiatric causes without first excluding hypoglycemia, hypothyroidism, hypocalcemia, anemia, and substance use 1, 2
• Sleep disturbances (including undiagnosed obstructive sleep apnea) commonly impair concentration and should be specifically assessed 3
• Medication side effects: Review all current medications, including over-the-counter supplements, as many can impair concentration 3, 1
• Avoid anchoring bias: A patient with known psychiatric history can still develop new medical conditions; maintain diagnostic vigilance 4