The thyroid and major depression

Thyroid hormones have been extensively investigated in major depression but abnormalities in thyroid hormones have not been found. Still in terms of treating depression thyroid hormones have had attractions. Meta-analyses indicate that augmentation of anti-depressants with triiodothyronine (T3) or thyroxine (T4) and can be helpful in the treatment of refractory depression.

There are definite difficulties with thyroid function in major depression but the problem is too little iodine. With dysregulation of the sodium-dependent multivitamin transporter (SMVT) iodine transport is impaired. The SMVT transports iodine. The role of the SMVT in the transport of iodine has not been emphasized to the same extent as the role of the SMVT in the transport of biotin and pantothenic acid. As it turns out the SMVT plays a key role in iodide homeostasis which if upset can result in major depression despite normal levels of thyroid hormones.

As an augmentation strategy to anti-depressants iodine would be taken three times a day. The Tolerable Upper level Limit for iodine for adults is 1100 micrograms per day. Tests on thyroid function would have to be obtained. Abnormal levels of thyroid hormones as shown by tests on thyroid function must be avoided.

If iodine can augment anti-depressants in the treatment of major depression this would point to the SMVT as playing a key role in psychiatric illnesses.

The SMVT and iodide

The sodium-dependent multivitamin transporter (SMVT) also transports iodide. How important the SMVT is for iodide transport is not clear. Supplementing with biotin and pantothenic acid, however, could competitively block the transport of iodide by the SMVT. There is another transporter of of iodide, the sodium/iodide cotransporter, (SLC5A5) which is largely expressed in the thyroid. The SMVT is expressed in the digestive tract.

Lithium or sodium bicarbonate for bipolar disorder?

From Interaction of α-Lipoic Acid with the Human Na+/Multivitamin Transporter (hSMVT)

‘Furthermore, the equimolar replacement of NaCl with LiCl or lowering the pH of the uptake assay from pH 7.4 to pH 5.5 (generation of a proton gradient across the oocyte membrane) resulted in R-[3H]LA accumulation in hSMVT-expressing oocytes that was indistinguishable from that observed in control oocytes (Fig. 2E)’ Control oocytes lack the hSMVT. The SMVT is the sodium-dependent multivitamin transporter and LiCl is lithium chloride. The SMVT transports biotin, pantothenic acid and lipoate.

The hSMVT is pH sensitive. Sodium bicarbonate buffers pH. If dysregulation of the SMVT in a key to to bipolar disorder as is argued in the page on bipolar disorder then sodium bicarbonate could be a key to the treatment of bipolar disorder. Sodium bicarbonate would also supply sodium which is required for transport by the SMVT.

The sodium of sodium bicarbonate could raise blood pressure. Each dosage of sodium bicarbonate would have to be taken with a 24 ounce glass of water to prevent dehydration which could raise blood pressure.

Blood pressure would have to be monitored. Individuals with high blood pressure may simply not be able to take sodium bicarbonate.

Sodium bicarbonate would be taken with biotin and pantothenic acid where biotin and pantothenic acid would be taken away from each other. Lipoic acid would not be taken as lipoic acid could competitively block the transport of pantothenic acid and biotin by the SMVT. Lipoic acid is synthesized on residues so there is no need to take lipoic acid.

Acetyl-CoA carboxylase is a biotin-dependent enzyme that is involved in the synthesis of non-essential fatty acids. Supplementation with beef tallow or ghee could be helpful. Taurine would be supplemented to assist with digestion of fatty acids.

If sodium bicarbonate, biotin, pantothenic acid, beef tallow or ghee and taurine are effective in the treatment of bipolar disorder then sodium bicarbonate, biotin, pantothenic beef tallow or ghee and taurine acid would be infinitely preferable for the treatment of bipolar disorder than lithium and/or anti-convulsants.

Supplements on the ‘supplements to be avoided’ list on the Treatment page would also be avoided. See the page on bipolar disorder for more on the SMVT