Missing molecule may indicate treatment-resistant depression

Researchers find that a deficiency of acetyl-L-carnitine is associated with a particular subtype of depression. Individuals with very low levels of this molecule often have highly severe symptoms and don’t respond to traditional antidepressants.

In the latest study, the scientists measured levels of LAC in blood samples taken from people diagnosed with MDD. They found that levels were significantly decreased in these patients, as compared to age-matched individuals without depression. Additional analysis revealed that patients with very low LAC exhibited more severe depression and were more likely to develop MDD early in life. Finally, the researchers found that decreased LAC was associated with having a history of childhood trauma and treatment-resistant depression, particularly in women.

“In patients with depression, something is causing a problem in the mechanisms related to the biology of LAC,” says Nasca. “And, surprisingly, the deficiency in LAC is even stronger in patients that don’t respond to standard antidepressants.”

These results suggest that LAC levels may be used as an effective biomarker–meaning, a measurable physiological trait that can indicate the presence of disease (sometimes in combination with other diagnostic techniques). In recent decades, physicians and researchers have been eager to identify biomarkers for psychiatric disorders, with limited success. This study represents unique progress, as it points to LAC screening as a potential tool for diagnosing a specific subtype of depression–a type that is highly severe, treatment-resistant, and that may stem, in part, from exposure to trauma early in life.

Source: Lack of a single molecule may indicate severe and treatment-resistant depression