L-Carnitine and Acetyl-L-Carnitine: Potential Novel Biomarkers for Major Depressive Disorder

The lack of biomarkers greatly limits the diagnosis and treatment of major depressive disorder (MDD). Endogenous L-carnitine (LC) and its derivative acetyl-L-carnitine (ALC) play antidepressant roles by improving brain energy metabolism, regulating neurotransmitters and neural plasticity. The levels of ALC in people and rodents with depression are significantly reduced. It is necessary to determine whether serum LC and ALC might be used as novel biomarkers for the diagnosis of MDD. Here, ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used to determine the concentration of LC and ALC in the serum of healthy controls and patients with MDD; among the latter, in patients who were responsive (effective group) and non-responsive (ineffective group) after 2 weeks of treatment. The diagnostic value of serum LC and ALC for MDD was assessed. Compared with healthy controls, the serum LC and ALC concentrations in patients with MDD were significantly decreased (P < 0.001). Pearson correlation analysis shows that the HDRS-24 score was negatively associated with serum ALC (r = -0.325, P = 0.007). Receiver operating characteristic (ROC) analysis revealed an area under the curve (AUC) of 0.801 with 83.1% sensitivity and 66.3% specificity for LC, and an AUC of 0.898 with 88.8% sensitivity and 76.4% specificity for ALC, differentiating patients with MDD from healthy controls. Furthermore, the concentration of LC and ALC in patients with depression was significantly increased in the effective treatment group, and no significant change was observed in the ineffective treatment group. These results suggest that serum LC and ALC may be novel biomarkers for the diagnosis of MDD.

[Personalized approach to the treatment of depression in the elderly]

AIM

To develop a personalized approach to the appointment of a complex antidepressant therapy in combination with drugs of neuroprotective and neurotrophic action in depressed elderly patients based on the selection of predictors of low therapeutic response (LTR).

MATERIAL AND METHODS

The study included 152 hospitalized patients, aged 60 years and older, with moderate and mild depression (ICD-10) who received monotherapy (44 people) with antidepressants of the new generation and complex therapy (108 people) with the same antidepressants in combination with neuroprotective drugs. In the monotherapy group, correlations between treatment efficacy (change in average total HAMD-17 scores) and a set of parameters, including socio-demographic data, results of psychopathological, somatic, standardized assessment and neuroimaging (CT) of the brain were analyzed. The validity of the established correlations as predictors of LTR was estimated based on a comparison of their frequency among the responders (≥50% reduction) and non-responders (<50% reduction). Comparison of the efficacy of therapy in groups of patients with mono - and complex therapy was carried out depending on the presence or absence of predictors of LTR.

RESULTS

LTR predictors are living alone, complaints about memory loss and signs of pronounced diffuse lesions of the subcortical white matter of the brain, which are significantly more frequently observed in non-responders (p<0.05). The increase in the number of predictors (2 and more) correlates with a significant decrease in therapeutic efficacy (p<0.001). Patients with complex in structure and protracted depressions tend to decrease in efficiency, and in most of them (more than 87% of cases) LTR predictors are detected. In patients with LTR predictors, the complex therapy is significantly more effective than monotherapy, allowing in all cases to achieve 50% reduction of depressive symptoms by the 4th week of treatment.

CONCLUSION

Personalized indications for the appointment of complex antidepressant therapy in combination with neuroprotective drugs in depressed elderly patients are formulated.

[The therapeutic potential of acetyl-L-carnitine in the treatment of cognitive and depressive disorders in the elderly]

The review is based on the assessment of the therapeutic potential of acetyl-L-carnitine (carnicetin) in the treatment of cognitive and depressive disorders in the elderly. The review describes the range of biochemical activity and mechanisms of action of acetyl-L-carnitine, assesses the efficacy and safety of acetyl-L-carnitine in gerontological practice. The results of preclinical and clinical studies of the use of acetyl-L-carnitine in world medical practice are analyzed.

Acetyl-L-Carnitine Supplementation and the Treatment of Depressive Symptoms: A Systematic Review and Meta-Analysis

OBJECTIVE

Deficiency of acetyl-L-carnitine (ALC) seems to play a role in the risk of developing depression, indicating a dysregulation of fatty acid transport across the inner membrane of mitochondria. However, data about ALC supplementation in humans are limited. We thus conducted a systematic review and meta-analysis investigating the effect of ALC on depressive symptoms across randomized controlled trials (RCTs).

METHODS

A literature search in major databases, without language restriction, was undertaken from inception until 30 December 2016. Eligible studies were RCTs of ALC alone or in combination with antidepressant medications, with a control group taking placebo/no intervention or antidepressants. Standardized mean differences (SMDs) and 95% confidence intervals (CIs) were used for summarizing outcomes with a random-effect model.

RESULTS

Twelve RCTs (11 of which were ALC monotherapy) with a total of 791 participants (mean age = 54 years, % female = 65%) were included. Pooled data across nine RCTs (231 treated with ALC versus 216 treated with placebo and 20 no intervention) showed that ALC significantly reduced depressive symptoms (SMD = -1.10, 95% CI = -1.65 to -0.56, I = 86%). In three RCTs comparing ALC versus antidepressants (162 for each group), ALC demonstrated similar effectiveness compared with established antidepressants in reducing depressive symptoms (SMD = 0.06, 95% CI = -0.22 to 0.34, I = 31%). In these latter RCTs, the incidence of adverse effects was significantly lower in the ALC group than in the antidepressant group. Subgroup analyses suggested that ALC was most efficacious in older adults.

CONCLUSIONS

ALC supplementation significantly decreases depressive symptoms compared with placebo/no intervention, while offering a comparable effect with that of established antidepressant agents with fewer adverse effects. Future large scale trials are required to confirm/refute these findings.