What is the next step in managing a 35-year-old female with mood swings, irritability, and social withdrawal, using alcohol and marijuana, with a history of depression and anxiety?

Next Step: Thyroid Function Test (D)

The next step is to obtain a thyroid function test (D) to rule out medical causes of psychiatric symptoms before proceeding with substance use evaluation or psychiatric treatment. 1

Rationale for Medical Clearance First

• Medical disorders must be excluded before attributing symptoms solely to psychiatric or substance use causes. Thyroid disease (both hyperthyroidism and hypothyroidism) can present with mood swings, irritability, anxiety, and depression—all present in this patient. 1

• The American Academy of Pediatrics and American College of Emergency Physicians support that routine laboratory testing should be medically indicated based on clinical suspicion from history and physical examination, not performed as protocol. 1

• This patient's presentation of mood swings, irritability, and unkempt appearance with pressured speech could represent thyroid storm (hyperthyroidism) or severe hypothyroidism, both of which require urgent medical intervention. 1

Why NOT Urine Drug Test (B) at This Stage

• Routine urine drug testing has little to no utility in changing patient management. Studies show that only 5% of routine toxicology screens are positive, with no changes in patient management or disposition. 1

• The American Family Physician guidelines indicate that urine drug testing should be performed when clinically indicated, not routinely, as it rarely impacts emergency department management. 1

• This patient already admits to alcohol and marijuana use, so a urine drug screen would only confirm what is already known and would not change the immediate management approach. 1

Why NOT CBC (A) or Pulmonary Function Test (C)

• While CBC could identify anemia or infection, thyroid dysfunction is more likely to cause this specific constellation of psychiatric symptoms (mood swings, irritability, social withdrawal, pressured speech). 1

• Pulmonary function testing has no role in the initial evaluation of psychiatric symptoms unless respiratory symptoms are prominent. 1

Clinical Algorithm After Thyroid Testing

If thyroid function is normal:

• Proceed with comprehensive substance use assessment using validated screening tools (AUDIT for alcohol, CAST for cannabis). 1
• This patient likely meets criteria for substance abuse or dependence given: recurrent use to cope with stress, history of depression/anxiety, and functional impairment (unkempt appearance, pressured speech suggesting possible intoxication or withdrawal). 1

If thyroid function is abnormal:

• Treat the underlying thyroid disorder first, as this may resolve or significantly improve psychiatric symptoms. 1
• Reassess psychiatric and substance use symptoms after thyroid stabilization. 1

Substance Use Disorder Considerations

• Depression and anxiety are significantly more common in patients with substance use disorders, particularly substance dependence. 1
• The bidirectional relationship between cannabis use and depression is well-established, with cannabis dependence showing the strongest association with incident major depressive disorder (OR=6.61). 2
• Co-occurring alcohol and cannabis dependence has the strongest association with major depressive disorder (OR=2.34) compared to either substance alone. 2

Treatment Planning After Medical Clearance

For substance abuse (if thyroid normal):

• Brief counseling using motivational interviewing approach. 1
• Close follow-up with ongoing assessment. 1
• Address the underlying depression/anxiety that is not being treated (patient is "not compliant on medication"). 1

For substance dependence (if meeting ≥3 criteria):

• Referral to specialty treatment for intensive behavioral therapy. 1
• Consider pharmacotherapy options depending on primary substance of concern. 1
• Combined cognitive behavioral therapy and pharmacotherapy shows small to moderate benefits for substance use disorders with psychiatric comorbidities. 1

Common Pitfalls to Avoid

• Do not assume psychiatric symptoms are solely due to substance use or primary psychiatric illness without ruling out medical causes. Thyroid disease, electrolyte abnormalities, and other metabolic disorders can mimic psychiatric presentations. 1

• Do not order routine laboratory panels without clinical indication. This wastes resources and rarely changes management. 1

• Do not overlook that this patient has untreated depression and anxiety ("not compliant on medication"), which significantly increases risk for substance use disorders and poor outcomes. 1, 2

• Recognize that marijuana use in patients with depression and alcohol use disorder is associated with worse outcomes, including greater depressive symptoms and worse functional status. 3