Bipolar Disorder: Open Access
Open Access

Research Finding States Lamotrigine is Effective in Treating Acute Bipolar Depression

Nazia Syed^{* *}Correspondence: Nazia Syed, Department of Medical Sciences, Banasthali Vidyapith, India, Email:

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Introduction

Lamotrigine is being used to treat bipolar illness as a maintenance treatment. According to new studies, lamotrigine could be an effective treatment for acute bipolar depression. A group of researchers looked at the efficacy of lamotrigine versus placebo for treating acute bipolar depression and saw if certain depression scale items responded better to lamotrigine treatment. While lamotrigine is routinely used to treat bipolar depression, there isn't enough evidence to back up its effectiveness.

Inconsistent Previous Research

The researchers analysed item-level data from 5 randomised placebocontrolled studies that tested the drug in 1072 patients with acute bipolar depression for the study. Each patient received treatment for seven to ten weeks. Lamotrigine's target dose is 200 mg per day, however greater doses are sometimes needed in clinical practise. Patients were given a maximum dose of 200 mg per day in four of the five trials. The researchers explained why they believed prior studies had generated mixed outcomes. "Suboptimal dose could explain the monotherapy trials' dismal findings," the scientists stated. "Another possibility for the contradictory results is that lamotrigine is more beneficial for particular depressed symptoms that were not examined in the original trials." Despite the trials' inconsistencies, the drug was approved as a maintenance therapy for bipolar disorder, but not as an acute depression treatment.

The Study

The Hamilton Depression Rating Scale and the Montgomery- Asberg Depression Rating Scale were used to assess depressed symptoms. "In the initial trials, relying on overall depression scale sum scores rather than tailored assessments of core depressive symptoms may have hampered signal discovery," the scientists stated. The researchers also compared the treatment groups' change scores on individual scale items. On both scales, the study produced statistically significant impacts on items measuring low mood/sadness, loss of interest/anhedonia, pessimism/guilt, and anergia/fatigue. They did, however, discover significant variance in baseline symptom prevalence, as well as the fact that items with higher baseline ratings had larger and statistically significant treatment benefits. The authors wrote, "The results revealed a strong treatment effect on core symptoms of depression." "The sensitivity of other scale items appeared to be limited by a floor effect." Firm conclusions cannot be formed due to the exploratory character of the study, albeit the findings were consistent with previous studies."

Limitations

However, the researchers said the study should be duplicated in order to confirm the hypothesis. “Given the exploratory nature of the analysis, the results need to be considered hypothesisgenerating until replicated with additional data,” the authors wrote. “Furthermore, the results may not generalize to broader clinical populations, and only clinician-rated symptom scales were used to measure efficacy.” The researchers also did not test for interactions with other variables including age and sex. Finally, the use of single items to assess symptoms is another limitation, although it does permit comparison with a significant number of industry-sponsored trials.

References

1. https://www.hcplive.com/view/lamotrigine-effective-acute-bipolar-depression
2. Bowden CL, Singh V, Weisler R, Thompson P, Chang X, et al. Lamotrigine vs. lamotrigine plus divalproex in randomized, placebo controlled maintenance treatment for bipolar depression. Acta Psychiatrica Scandinavica. 2012; 126: 342-350
3. Nierenberg AA, Ostacher MJ, Calabrese JR, Ketter TA, Marangell LB, et al. Treatment-resistant bipolar depression: A STEP-BD equipoise randomized effectiveness trial of antidepressant augmentation with lamotrigine, inositol, or risperidone. Am J Psychiatry. 2006; 163: 210-216
4. Goldsmith DR, Wagstaff AJ, Ibbotson T, Perry CM. Lamotrigine.Drugs.2003; 63: 2029-2050.
5. Mitchell PB, Hadzi-Pavlovic D, Evoniuk G, Calabrese JR, Bowden CL. A factor analytic study in bipolar depression, and response to lamotrigine.CNS Spectrums.2013; 18: 214-224.