What laboratory tests should be ordered to evaluate anxiety in a 15-year-old female?

Laboratory Tests for Anxiety in a 15-Year-Old Female

Laboratory testing is not routinely recommended for the evaluation of anxiety disorders in adolescents, but targeted testing should be performed if medical conditions are suspected based on history and physical examination findings. 1, 2

Recommended Laboratory Tests When Indicated

When medical causes of anxiety are suspected based on clinical presentation, consider these targeted tests:

• Thyroid function tests (TSH, free T4) - Thyroid dysfunction can mimic or exacerbate anxiety symptoms 2
• Complete Blood Count (CBC) - To evaluate for anemia, infection, or other hematologic abnormalities 2
• Basic metabolic panel - To assess electrolytes, glucose, kidney function 2
• Glucose testing - Hypoglycemia can present with anxiety-like symptoms 1

Medical Conditions That Can Present as Anxiety

Several medical conditions can manifest with anxiety-like symptoms in adolescents and should be considered:

• Hyperthyroidism
• Hypoglycemia
• Caffeine excess
• Asthma
• Migraine
• Diabetes
• Lead intoxication
• Cardiac arrhythmias
• Pheochromocytoma
• Seizure disorders 1

Screening and Assessment Approach

Rather than extensive laboratory testing, the American Academy of Child and Adolescent Psychiatry recommends:

1. Comprehensive clinical evaluation with separate interviews of the adolescent and parents/guardians
2. Standardized screening tools such as:
   • Generalized Anxiety Disorder-7 (GAD-7) - A 7-item self-report scale with excellent validity 2, 3
   • GAD-2 (ultra-short version) for rapid initial screening 2

Important Considerations

• Avoid overreliance on laboratory testing - This can lead to false positives and unnecessary medical workups 2
• Focus on psychiatric comorbidities - Anxiety disorders commonly co-occur with depression, ADHD, and substance use disorders 1
• Consider developmental factors - Normal developmental fears should be distinguished from pathological anxiety 1

When to Refer

Consider referral to psychiatry for:

• Moderate to severe anxiety (GAD-7 score ≥10)
• Risk of self-harm
• Severe functional impairment
• Poor response to initial interventions 2

Common Pitfalls to Avoid

1. Overreliance on laboratory testing - Anxiety disorders are primarily diagnosed through clinical evaluation, not laboratory findings
2. Missing medical mimics - While uncommon, medical conditions can present as anxiety and should be considered when symptoms are atypical
3. Failing to screen for comorbidities - Depression frequently co-occurs with anxiety in adolescents
4. Overlooking substance use - Caffeine, stimulants, and other substances can exacerbate anxiety symptoms

Remember that anxiety disorders are common in adolescent females, with approximately 40% of women affected during their lifetime, twice the rate seen in men 2. Early identification and appropriate treatment can significantly improve outcomes.