When should prolactin levels be checked in patients with depression?

When to Check Prolactin Levels in Patients with Depression

Prolactin levels should be checked in patients with depression who are taking antipsychotic medications or who present with specific symptoms such as menstrual disturbances, galactorrhea, sexual dysfunction, or hypogonadism. 1

Indications for Prolactin Testing in Depressed Patients

Medication-Related Indications

• Antipsychotic medications: Priority testing for patients on:
  • Prolactin-raising antipsychotics (conventional neuroleptics, amisulpride, risperidone) 2
  • Any antipsychotic medication, as all can potentially cause hyperprolactinemia to varying degrees 2
  • Testing recommended after 3 months of stable dose treatment 2

Symptom-Based Indications

• In women with depression:

  • Menstrual irregularities or amenorrhea
  • Galactorrhea (milk discharge)
  • Unexplained infertility
  • Sexual dysfunction (decreased libido)

• In men with depression:

  • Sexual dysfunction (decreased libido, erectile dysfunction)
  • Gynecomastia
  • Signs of hypogonadism

Endocrine-Related Indications

• Patients with low testosterone levels combined with low or low/normal luteinizing hormone levels 1
• Patients with suspected pituitary disorders

Clinical Relevance in Depression

While older research found no correlation between prolactin levels and depression in general ambulatory medical populations 3, specific cases warrant attention:

• Hyperprolactinemia can cause psychological symptoms including anxiety and depression 4
• Case reports document major depressive disorder induced by prolactinoma 5
• Patients with hyperprolactinemia have a 3.52 times higher risk for depression and 3.32 times higher risk for anxiety 4

Monitoring Recommendations

For depressed patients on antipsychotic medications:

1. Baseline measurement: Check prolactin levels before starting antipsychotic treatment 2
2. Follow-up measurement: Recheck after 3 months of stable dose treatment 2
3. Symptom-triggered testing: Check prolactin if any symptoms of hyperprolactinemia develop during treatment 2

Management Considerations

If hyperprolactinemia is detected in a depressed patient:

• Rule out other causes of elevated prolactin
• For medication-induced hyperprolactinemia:
  • Consider dose reduction of the antipsychotic
  • Consider switching to a prolactin-sparing antipsychotic (clozapine, aripiprazole, olanzapine) 2
  • Use dopamine agonists only in exceptional circumstances as they may worsen psychiatric symptoms 2

Important Caveats

• Hyperprolactinemia may be asymptomatic, especially at lower elevations
• Women are more likely than men to develop hyperprolactinemia (47% vs. 18% in patients on antipsychotics) 2
• Long-term hyperprolactinemia can lead to bone loss, particularly in women with associated amenorrhea 2
• Patients often don't spontaneously report sexual dysfunction or other symptoms of hyperprolactinemia, requiring direct questioning 2