Patients with comorbid anxiety and mood disorders who have reduced, albeit “normal” serum levels of thyroid-stimulating hormone (TSH) may be at increased risk for suicidal ideation, new research suggests.
Vilma Liagaudaite
In a cross-sectional study, clinical data on diagnosis, medication use, and symptom scores were gathered, along with assessments of blood levels of thyroid axis hormones, in patients with both anxiety and mood disorders.
After investigators accounted for age, gender, symptoms, medication use, and other potential confounders, patients with suicidal ideation were 54% less likely to have higher TSH levels. There was no association found with other thyroid hormones.
Based on the results, the assessment of thyroid hormone levels “may be important for suicide prevention and might allow clinicians to evaluate the potential of the suicidal ideation risk in individuals with [anxiety and mood disorders],” co-investigator Vilma Liaugaudaite, PhD student, Neuroscience Institute of the Lithuanian University of Health Sciences, Palanga, and colleagues note.
The findings were presented at the 34th European College of Neuropsychopharmacology (ECNP) Congress.
‘Complex mechanism’
Ms. Liaugaudaite told this news organization that thyroid hormones are known to have a “profound” effect on mood and behavior.
Recent studies show “various degrees of hypothalamic-pituitary-thyroid axis dysregulation are associated with suicidal behavior” in patients with depression, she added.
Noting that disturbances in the serotonin system “constitute the most common biochemical abnormality associated with suicidal behavior,” Ms. Liaugaudaite said it is thought thyroid hormones “are involved in a complex compensatory mechanism to correct reduced central 5-hydroxytryptamine activity” via lower TSH levels.
In addition, hypersecretion of thyrotropin-releasing hormone, which stimulates the release of TSH, “has been considered a compensatory mechanism to maintain normal thyroid hormone secretion and normalize serotonin activity in depressed patients,” she said.
To investigate associations between thyroid axis hormones and suicidality in individuals with comorbid anxiety and mood disorders, the researchers assessed consecutive patients attending a stress disorders clinic.
Sociodemographic and clinical information was gathered, and patients completed the Mini International Neuropsychiatric Interview, the Patient Health Questionnaire-9 (PHQ-9), and the General Anxiety Disorder-7 (GAD-7) scale.
Fasting blood samples were also tested for free thyroxine (FT4), free triiodothyronine (FT3), and TSH levels.