5-11-methenyltetrahydrohomofolate and Depressive-Disorder

A substantial proportion of depressed patients show only partial or no response to antidepressants, and even among responders to antidepressant treatment, residual symptoms are rather common. When depressions do not respond adequately to treatment with an antidepressant, clinicians may choose to keep the same antidepressant and add another "augmenting" compound. Such augmentation strategies involve the use of a pharmacologic agent that is not considered to be a standard antidepressant but may boost or enhance the effect of an antidepressant. Alternatively, clinicians may choose combination strategies, in which they combine the antidepressant that did not produce adequate response with another antidepressant, typically of a different class. There are only a few controlled clinical trials of these 2 strategies among patients with treatment-resistant depression or among patients who have only partially benefited from antidepressant treatment. Most of the time, clinicians' decisions are, therefore, guided by anecdotal reports, case series, and by some relatively smaller, uncontrolled clinical trials. These augmentation and combination strategies appear to be relatively safe and effective approaches to treatment-resistant depressions, although there is a relative paucity of controlled studies to support their efficacy. These strategies typically aim at obtaining a different neurochemical effect than the one obtained with the antidepressant that has not produced adequate response. While drug-drug interactions may limit the use of some of these strategies, the potential loss of partial benefit from the failed drug inherent in switching may increase the acceptability of augmentation and combination strategies among partial responders. Further studies are clearly needed to evaluate the comparative efficacy and tolerability of these different approaches in treatment-resistant depressions.

Topics: Antidepressive Agents; Antidepressive Agents, Tricyclic; Antipsychotic Agents; Central Nervous System Stimulants; Dehydroepiandrosterone; Depressive Disorder; Dopamine Agents; Drug Administration Schedule; Drug Interactions; Drug Therapy, Combination; Fatty Acids, Omega-3; Folic Acid; Humans; Selective Serotonin Reuptake Inhibitors; Treatment Outcome

To investigate the modifying effects of two candidate genes (serotonin transporter gene linked promoter region (5-HTTLPR) and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphisms) on the associations between general somatic morbidity and incidence of depression in an East Asian population with high frequencies of potential risk alleles.. With a 2-year prospective study of a community sample (N = 521) of older people (aged 65+), information on baseline number of health complaints, diagnosis of moderate/severe depressive syndrome (Geriatric Mental State), and genotypes for 5-HTTLPR and MTHFR C677T polymorphisms were ascertained. Interactions between somatic morbidity and the two genotypes were investigated for incident depression.. Incident depression was present in 63 (12%) and was associated with worse somatic health. Significant interactions between number of somatic complaints and both genotypes were observed. For the 5-HTTLPR genotypes, the association between the number of somatic disorders and depression was significant in s/s homozygotes (chi2 = 8.80 (1 df), p = .003) but not in heterozygotes (chi2 = 0.23, p = .634) or l/l homozygotes (chi2 = 0.04, p = .840). For the MTHFR genotypes, the association between the number of somatic disorders and depression was significant in T/T homozygotes (chi2 = 4.97, p = .026) but not in C/T heterozygotes (chi2 = 1.24, p = .265) or C/C homozygotes (chi2 = 1.04, p = .307).. These findings suggest that associations between general somatic morbidity and late-life depression are modified by at least two genes, and that elders with particular genotypes are at greater risk for onset of depression in the presence of somatic ill health.

Topics: Aged; Chronic Disease; Depressive Disorder; DNA Primers; Female; Folic Acid; Genotype; Health Status; Humans; Male; Polymerase Chain Reaction; Polymorphism, Genetic; Prospective Studies; Serotonin Plasma Membrane Transport Proteins; Severity of Illness Index; Somatoform Disorders; Syndrome