Depression is not a single disease. The term refers to a cluster of feelings and behaviors, brought on by a variety of underlying causes. And, unfortunately, it is often difficult to determine which type of depression a person has. According to a new multi-institutional study, doctors may one day be able gain insight into an individual's depression by analyzing his or her blood. Patients with a particular type of depression have decreased blood levels of the molecule acetyl-L-carnitine (LAC) -- a finding that may lead to improved diagnosis and treatment of major depressive disorder (MDD).
Naturally produced by the body, LAC performs a number of crucial tasks in the brain. For example, the molecule regulates energy metabolism and interacts with DNA to promote the expression of important genes. Specifically, it acts on a gene that controls levels of the neurotransmitter glutamate -- a chemical implicated in almost everything that the brain does.
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.
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.
Category(s):Depression
Source material from Science Daily
