Acetyl-L-carnitine and ?-lipoic acid: possible neurotherapeutic agents for mood disorders?

Background: Mood disorders are associated with decrements in cognitive function, which are insufficiently treated with contemporary pharmacotherapies.
Objectives: To evaluate the putative neurotherapeutic effects of the mitochondrial cofactors, L-carnitine, acetyl-L-carnitine, and α-lipoic acid; and to provide a rationale for investigating their efficacy in the treatment of neurocognitive deficits associated with mood disorders.
Methods: A PubMed search of English-language articles published between January 1966 and March 2007 was conducted using the search terms carnitine and lipoic acid.
Results: L-carnitine and α-lipoic acid may offer neurotherapeutic effects (e.g., neurocognitive enhancement) via disparate mechanisms including antioxidant, anti-inflammatory, and metabolic regulation. Preliminary controlled trials in depressed geriatric populations also suggest an antidepressant effect with acetyl-L-carnitine.
Conclusions: L-carnitine and α-lipoic acid are pleiotropic agents capable of offering neuroprotective and possibly cognitive-enhancing effects for neuropsychiatric disorders in which cognitive deficits are an integral feature.