According to a recent study Acetyl -L-Carnitine has been shown to reduce depressive symptoms.

Psychosomatic Medicine recently published a systematic review and meta-analysis looking at the reduction of depressive symptoms compared to placebo with the use of acetyl–L–carnitine. The analysis included 12 randomized controlled trials. The total number of patients was 791, 65% of those were women. The mean age was 54 years. 11 of the studies looked at acetyl–L–carnitine alone, one of the studies used acetyl–L–carnitine in combination with traditional antidepressant treatment.

Results from the pooled data showed that acetyl–L–carnitine reduced depressive symptoms at a statistically significant level when compared with placebo or no intervention. Interestingly, acetyl–L–carnitine had superior effects in older compared to younger participants. The data also indicated that increased acetyl–L–carnitine doses corresponded to greater improvement in depressive symptoms.

The investigators noted that acetyl–L–carnitine appeared to have similar effects to common antidepressants with fewer side effects overall. The investigators were hopeful that the study would lead to larger, randomized, controlled studies.