стратегии аугментации l-метилфолатом при резистентной депрессии

Significant Benefit

In the TRD-1 study, 148 patients were randomized in a 2:3:3 design to receive either L-methylfolate for 60 days (7.5 mg/d in phase 1 and 15 mg/d in phase 2), placebo for 30 days followed by L-methylfolate for 30 days (7.5 mg/d), or placebo for 60 days.

The 75-patient TRD-2 was identical in design to TRD-1 except for a target dose of 15 mg/d of L-methylfolate throughout both phases.

The coprimary endpoints for both studies were the differences in response rates and in degree of improvement in the Hamilton Depression Rating Scale (HDRS-17) between treatment groups. An HDRS-17 response was defined asa 50% or greater reduction in HDRS-17 scale scores during treatment or a final score of 7 or less.

The TRD-1 study found no difference in outcome between the treatment groups.

The TRD-2 study showed greater efficacy for adjunctive 15 mg/d of L-methylfolate administered for up to 30 days vs placebo when added to continued SSRI therapy plus placebo on both primary outcome measures (degree of change and response rates according to the HDRS, P = .05 and .04, respectively).

There was no difference in the rates of treatment withdrawal due to adverse events in the L-methylfolate 15 mg/d/antidepressant and the placebo/antidepressant groups.

Finally, the number of patients needed to treat (NNT) for a response in the TRD-2 study was between 5 and 6 patients in favor of adjunctive 15 mg/dof L-methylfolate vs placebo. "This is on a par with NNTs reported for other augmentation strategies in MDD," Dr. Papakostas said.

Adjunctive L-Methylfolate May Help in Treatment-Resistant Depression

PHQ-9

Table 3. PHQ-9

1. Over the past 2 weeks, how often have you been bothered by any of the following problems?
	Not at all (0)	Several days (1)	More than half the days (2)	Nearly every day (3)
a. Little interest or pleasure in doing things
b. Feeling down, depressed, or hopeless
c. Trouble falling/staying asleep, sleeping too much
d. Feeling tired or having little energy
e. Poor appetite or overeating
f. Feeling bad about yourself -- or that you are a failure or have let yourself or your family down
g. Trouble concentrating on things, such as reading the newspaper or watching television
h. Moving or speaking so slowly that other people could have noticed. Or the opposite -- being so fidgety or restless that you have been moving around a lot more than usual
i. Thoughts that you would be better off dead or of hurting yourself in some way
2. If you checked off any problem on this questionnaire so far, how difficult have these problems made it for you to do your work, take care of things at home, or get along with other people?
	Not difficult at all	Somewhat difficult	Very difficult	Extremely difficult

Table 4. Interpretation of PHQ-9 Results

Score/ Symptom Level	Treatment
0-4 No depression	Consider other diagnoses
5-9 Minimal	▪ Consider other diagnoses ▪ If diagnosis is depression, watchful waiting is appropriate initial management
10-14 Mild	▪ Consider watchful waiting ▪ If active treatment is needed, medication or psychotherapy is equally effective; consider function score in choosing treatment
15-19 Moderate	▪ Active treatment with medication or psychotherapy is recommended ▪ Medication or psychotherapy is equally effective
20-27 Severe	▪ Medication treatment is recommended ▪For many people, psychotherapy is useful as an additional treatment ▪ People with severe symptoms often benefit from consultation with a psychiatrist

Data from Kroenke K, Spitzer R. Psychiatr Ann. 2002;32:509-521.

A number of combinations have some benefit in selected patients, including:

• Lithium augmentation at stage 3 of STAR*D resulted in remissions in 15.9%.^[84] Lithium in combination with SSRIs and TCAs also has been effective in placebo-controlled studies, most involving small numbers of subjects. Such treatment requires monitoring of lithium levels, because there is a small difference between therapeutic and toxic levels.^[85]
• Thyroid hormone, and particularly triiodothyronine, has been studied for augmentation with the TCAs. In the STAR*D study, at step 3, augmentation with triiodothyronine led to a remission rate of 24.7%.^[84] Placebo-controlled studies have involved small numbers of subjects and have had mixed results.^[86]
• A heterocyclic-SSRI combination in 1 small study produced more rapid treatment onset and increased the likelihood of remission.^[87] In the study, a combination of fluoxetine and desipramine (a norepinephrine reuptake inhibitor) was more effective in achieving remission than either drug used as monotherapy: 53.8% for the combination, compared with 7.1% and 0%, respectively. However, such combinations can produce the serotonin syndrome, which is potentially life-threatening, and the dose of the heterocyclic must be adjusted using blood levels because SSRIs increase TCA levels through CYP-450 isoenzyme interactions (eg, fluoxetine increases the levels of desipramine 3- to 4-fold).^[88] Consequently, this augmentation strategy should rarely be considered in primary care.
• Mirtazapine has recently been evaluated in combination therapy with an SSRI (fluoxetine), an SNRI (venlafaxine), or bupropion.^[89] The investigators found that all 3 combinations were more effective than fluoxetine alone in achieving remission (52%, 58%, 46%, respectively, compared with 25%). In patients who responded, double-blind discontinuation resulted in relapse in about 40%. Of note, treatment was initiated with these combinations, rather than mirtazapine being used as an augmenting agent in those not initially responding.
• Methylfolate and folate have been used to augment SSRIs, resulting in increased rates of remission, particularly in women.^[90] The degree to which the response is due to folate deficiency, and whether methylfolate is of greater benefit due to its increased ability to cross the blood-brain barrier, are subject to further research.
• Antidepressants and hypnotics have been used together, with early improvement not only in sleep measures, but also in rates of depression remission.^[91]
• Stimulant drugs have been used as augmentation of heterocyclics or SSRIs.^[92] Of note, in individuals with comorbid medical illness, amphetamine stimulants should be used with caution, particularly if cardiac disease is potentially present.

Clinical and Pharmacologic Strategies to Achieve Remission in Depression

Роль L-метилфолата в терапии депрессивных расстройств

Folate is a water soluble B vitamin (B9), considered one of the 13 essential vitamins. The primary function of folate is the transfer of methyl and formyl groups, thus, it is essential for cell growth and reproduction, the breakdown and utilization of proteins, the formation of nucleic acids, red blood cell maturation, and a variety of CNS reactions. Dihydrofolate is the dietary form found in orange juice, spinach, asparagus, beans, liver, yeast, whole grain cereals, and eggs. Folic acid is the synthetic form of folate in over-the-counter vitamins and used to fortify the food supply (to help prevent neural tube defects, the FDA mandated folic acid fortification of flour in 1998). Folic acid is also the predominant form used in prescription strength prenatal vitamins. Both folic acid and dihydrofolate are not biologically active forms of folate, but are essentially pro-drugs, and must undergo enzymatic transformation to L-methylfolate in order to be used by cells, and unlike other forms of folate, L-methylfolate readily crosses the blood-brain barrier for use in the CNS.


Almost 85% of dietary folate and nearly all supplemental folic acid is absorbed into the venous system in the proximal small intestine. The enzymatic conversion begins in the intestinal wall—it is a three step process for dihydrofolate, and a four step process for folic acid (Slide 3). Folic acid is converted to dihydrofolate (DHF) by dihydrofolate reductase enzyme (DHFR), and DHF is then converted to tetrahydrofolate (THF). The conversion of THF to 5,10-methyleneTHF follows. Finally, the conversion of 5,10-methyleneTHF to L-methylfolate is achieved by the methyltetrahydrofolate reductase enzyme (MTHFR). This last step completes the four step transformation process by which the bioactive cofactor, L-methylfolate, is made available to the brain to be used in the synthesis of monoamine neurotransmitters associated with mood regulation (serotonin, norepinephrine, and dopamine).

There are five trials that examine folate therapy in depressive disorders. In a study59 with patients who had low or borderline low RBC folate, depressed patients on tricyclic antidepressants or MAOIs were augmented with methylfolate 15 mg (L-methylfolate 7.5 mg) experienced significantly greater clinical improvement and social improvement at 3 months (P<.02) and 6 months (P<.01) compared to patients treated with antidepressants alone. The methylfolate-augmented patients continued to improve for 6 months compared to patients augmented with placebo, and none experienced relapse. In a separate double-blind, controlled trial60 comparing methylfolate 50 mg/day to trazodone 100 mg/day, depressed patients experienced a significant decrease in HAM-D scores at 4 and 8 weeks in both groups, with response rates in the methylfolate group at 45%, and in the trazodone group (not statistically significant) at 29%.


An open label trial61 of methylfolate as monotherapy in elderly depressed subjects demonstrated an 81% response rate (>50% reduction in HAM-D) by 6 weeks of therapy. A second monotherapy study examined a depressed population of 36 chronic alcoholics. After a week of placebo wash-out, subjects received 4 weeks of 90 mg methylfolate therapy. This dosing (30 mg TID) significantly improved depressive symptoms based on the HAM-D scale with the majority reporting improved mood and less fatigue (P<.01).62 Alpert and colleagues63 conducted an open label trial augmenting selective serotonin reuptake inhibitor (SSRIs) with folinic acid in patients who had failed at least 4 weeks of SSRI therapy. The response to folinic acid was not robust (P<.01, n=22), but it was well tolerated overall.

The standard dose of L-methylfolate for the augmentation of antidepressants is one 7.5 mg tablet/day. No titration is necessary, and it is not associated with withdrawal symptoms at discontinuation. The maximum amount of L-methylfolate that can be absorbed in one dose is ~15 mg.67 If more than one 7.5 mg tablet/day is needed, it may be prudent to give in divided doses. All reported adverse events occur at placebo rates or lower, and overall it is an extremely well tolerated agent, allowing patients to continue L-methylfolate therapy as long as necessary to maintain remission. There are no known contraindications and no known drug interactions.

The Role of L-methylfolate in Depressive Disorders

Потенцирование антидепрессантов: L-метилфолат

Novel Therapeutics for Depression: L-methylfolate as a Trimonoamine Modulator and Antidepressant-Augmenting Agent