Do plasma NfL levels change in people with anxiety disorders compared to others?

Plasma neurofilament light chain (NfL) is a protein that can indicate nerve damage. A large study using data from the UK Biobank examined whether having a psychiatric diagnosis changes NfL levels in the blood. The study found that anxiety disorders are associated with lower NfL levels relative to the general population, while depression and bipolar disorder are associated with higher levels.

What the research says

In a population-based study of over 47,000 participants, researchers compared plasma NfL levels across different psychiatric diagnoses against a reference group ³. The analysis controlled for neurological conditions, heart and metabolic health issues, and substance use to isolate the effects of the psychiatric diagnoses themselves ³.

The results showed that individuals with anxiety disorders had significantly lower plasma NfL levels than the reference population, with a difference score of -0.07 ³. In contrast, people with bipolar disorder and recurrent depressive disorder had higher NfL levels ³. This suggests that the biological markers of nerve injury differ between anxiety disorders and mood disorders like depression or bipolar disorder ³.

Other studies in the provided sources discuss genetic factors and treatment effects for anxiety but do not address plasma NfL levels ¹²⁴⁶. For example, research on genetic scores shows that anxiety disorders share some genetic overlap with depression, but this does not explain the opposing direction of NfL changes seen in the blood test results ².

What to ask your doctor

• How do my anxiety symptoms relate to biological markers like plasma NfL?
• Could lower NfL levels in my blood be a sign of my specific anxiety disorder?
• Are there other blood tests that might help track my anxiety or nerve health?
• How might my anxiety disorder affect my overall nerve health compared to depression?