Understanding The Use Of Thyroid Hormones For Treatment Of Bipolar Disorder
Of all the treatments known for rapid cycling, Levothyroxine has the highest evidence base and is the most promising in addition to having few or any side effects.
In fact, in this recent article review, Levothryoxine has been ranked as the top choice for treatment of rapid cycling with recommendation grade A.
Here, we outline how the use of thyroid hormones for treating bipolar disorder is supported by evidence.
All clinicians are required to follow evidence-based medicine in their advice and management to patients, as required by the Good Medical Practice (GMC):
- In providing clinical care you must:
b provide effective treatments based on the best available evidence
Assessing Evidence-Based Medicine Levels
Evidence-based medicine requires clinicians to consider the best evidence when making decisions for an individual’s care. The Centre for Evidence-Based Medicine (CEBM) sets out an approach for appraising medical research and assessing the level of evidence:
- Evidence-based medicine level 1B, a Randomised Controlled Trial or RCT (recommendation grade A or B) is higher than level 2A, (Systematic Review of cohorts, e.g. 1million subjects).
A panel of experts who have not appraised the literature and rely on their knowledge of physiology, first principle (thyroid is dangerous or ineffective), or bench research, rank as the lowest possible level of evidence, namely level 5 with recommendation Grade D. This level of evidence must not be followed if higher levels of evidence are present.
The London Psychiatry Centre publications stand at level 2B, namely 2 consistent cohort studies with Grade B recommendation.
What Is The Level Of Evidence For Thyroid Hormones In Bipolar Treatment?
- According to evidence-based medicine, high dose thyroid is NOT harmful in bipolar disorder patients.
Supporting evidence:
* Two consistent safety studies at level 1 give recommendation grade A.
- According to evidence-based medicine, high dose thyroid IS effective in bipolar disorder
Supporting evidence:
| Efficacy and Safety of Supraphysiologic Doses of Levothyroxine for Patients With Bipolar Depression in Adults: A Systematic Review. | Evidence level: 1, recommendation grade A for safety and effectiveness. |
| Adjunctive Thyroid Hormone Treatment in Rapid Cycling Bipolar Disorder: A Double-Blind Placebo-Controlled Trial of Levothyroxine (L-T4) and Triiodothyronine (T3) | Evidence level: 1B, recommendation A or B. |
| High-Dose Levothyroxine for Bipolar Disorder; the Potential Role of Thyroid Function and Genetic Tests. Report from Twenty Cases. | Evidence level: 2B Our publication. |
| Bipolar spectrum disorders treatment with a new protocol of High Dose Levothyroxine (HDT) and rTMS and thyroid genetic mutations: a cohort evaluation | Evidence level: 2B Our poster, presented at the European Psychiatric Association 30 congress June 2022 |
The Safety Of Thyroid Hormone For Treating Bipolar According To Evidence-Based Medicine
Of the 4 RCTs available for the treatment of rapid cycling, thyroid treatment may be the best designed with the lowest drop out rates.
High dose thyroid hormone is considered to be evidence-based medicine level 1B (recommendation grade A or B).
Our own publications are at level 2B (recommendation grade B) for safety and effectiveness.
It is desirable to have level 1A, namely systematic review, but this does not exist for rapid cycling or subthreshold bipolar disorders.
All clinicians must take that into account when prescribing. If advising patients to stop treatment based on blood test results, this will contradict the evidence base which shows that the blood tests are by definition abnormal (Supraphysiological).
Please note that the combination of rTMS with high dose thyroid hormone is patented by The London Psychiatry Centre.
