Low acetyl-l-carnitine: a biomarker for depression

Posted on Mon, 3 Sep 18

Identifying low levels of the amino acid acetyl-l-carnitine may help personalise nutritional treatment for people with depression.   

Previously, a research group found that deficiency in acetyl-l-carnitine (ALC) resulted in impaired neurological function and depressive behaviour in rats. They also found that low ALC was a biomarker that helped identify the development of depression in response to stress. 

To see if these findings were relevant in humans they measured ALC levels in people with major depression. The results showed that ALC levels were reduced when compared to people without depression [1]. 

Remarkably, additional analysis found that that the degree of ALC deficiency was related to worse depressive symptoms as well as a history of treatment-resistant depression. Further, the ALC deficiency was worse among women and those with a history of childhood trauma and emotional neglect. 

“…these translational findings support further exploration of ALC as a therapeutic target that may help to define individualized treatments in biologically based depression subtype consistent with the spirit of precision medicine,” commented the study investigators, a collaborative group from Stanford University School of Medicine, California and Rockefeller University, New York.

Earlier this year a meta-analysis of 12 clinical studies in which ALC had been used to treat depression was published, showing that ALC is as effective as anti-depressant drugs, with fewer side effects [2]. Most studies used 3 g daily. 

References: 

1. Nasca C, Bigio B, Lee FS, Young SP, Kautz MM, Albright A, Beasley J, Millington DS, Mathé AA, Kocsis JH, Murrough JW, McEwen BS, Rasgon N. Acetyl-l-carnitine deficiency in patients with major depressive disorder. Proc Natl Acad Sci U S A. 2018 Aug 21;115(34):8627-8632.

2. Veronese N, Stubbs B, Solmi M, Ajnakina O, Carvalho AF, Maggi S. Acetyl-L-Carnitine Supplementation and the Treatment of Depressive Symptoms: A Systematic Review and Meta-Analysis. Psychosom Med. 2018 Feb/Mar;80(2):154-159.