Clinical Research Review: Thiamine to Enhance Conventional Anti-depressant Treatment
By: Tori Hudson, ND
Author: Ghaleiha A, Davari H, Jahangard L, et al.
Reference: Adjuvant thiamine improved standard treatment in patients with major depressive disorder: results from a randomized, double-blind, and placebo-controlled clinical trial. Eur Arch Psychiatry Clin Neurosci ; published online March 2016.
Design: This 12 week, randomized, double-blind, placebo-controlled clinical trial investigated the effect of adjuvant thiamine on individuals with major depressive disorder (MDD). Men and women were recruited from a hospital in Iran and were randomized and then given either thiamine 300 mg/day or placebo. Patients were also given fluoxetine 20 mg/day, a standard SSRI, for at least 12 weeks.
Participants: After a diagnosis of MDD in 70 inpatients, 51 met the inclusion. Mean age was 35 years of age, 53% men and 47% women and were inpatients. Inclusion criteria included the following: 1) diagnosis by a psychiatrist and not involved in any other study, 2) a Hamilton Depression Rating Scale (HDRS) score of 25 or higher (= severe depressive disorder), 3) no comorbid psychiatric disorders 4) between the ages of 18 and 50. Patients were excluded if: 1) the inclusion criteria were not met, 2) had other psychiatric disorders such as anorexia nervosa, 3) had a gastrointestinal disorder within the previous 4-8 weeks, 4) Wernicke syndrome 5) history of alcohol or substance abuse in the previous year 6) congestive heart failure and use of long term diuretics, 7) magnesium deficiency, 8) thiamine deficiency, 9) allergy or intolerance to thiamine, 10) women who were pregnant or lactation, 11) hyperthyroidism, 12) intention to become pregnant within the subsequent 2 months.
Primary outcome: The Hamilton Depression Rating Scale (HDRS) was used to assess the hypothesis that adjuvant thiamine would reduce depression in those taking an SSRI when compared to adjuvant placebo and SSRI.
Key findings: HDRS symptoms were rated at baseline, and after 3, 6 and 12 weeks at the end of the study. Between baseline and the end of the study, depression had reduced in both groups. Adjuvant thiamine improved symptoms of depression after 6 weeks of treatment with the SSRI and thiamine, with full remission and partial responses rates greater in the thiamine vs the placebo group.
Those improvements remained stable throughout the study duration, although the mean difference at week 12 was no longer statistically significant.
Practice Implications: The key conclusion of this study is that by using thiamine in addition to an SSRI, fluoxetine in this case, the benefits of the SSRI would be seen sooner than if using just the SSRI alone. In addition to the obvious benefits of thiamine causing an enhanced response rate to the SSRI, there is another important consideration. It is reported that as many as 50% of patients treated with conventional anti-depressants discontinue their medication within the first month. It is thought that this high dropout rate is due to either adverse effects of the medication or due to the lack of effect by week two. In essence, in this study, the thiamine at 300 mg/day seemed to speed up the treatment improvements of the SSRI. This will be a safe, simple, inexpensive adjunct to standard SSRI anti-depressant treatment. Would it also be effective with St John’s wort or other alternative anti-depressant therapies affecting serotonin mechanisms?