How did psychiatrists figure out that low folate causes depression?

And which of the many folate forms is most effective?

Find out in today's podcast.

Welcome to the Carlet Psychiatry Podcast, keeping psychiatry honest since 2003.

I'm Chris Agen, the editor-in-chief of the Carlat Psychiatry Report.

And I'm Kelly Newsom, a psychiatric MP and a dedicated reader of every issue.

Last week, we learned how folate was discovered when the British haematologist Lucy Wills

treated pregnant women with anemiaemia with a folate-rich

yeast extract marmite. Lucy made this discovery in 1931. By the early 1960s, new technology

made it easy to measure folate in clinical practice, and that is where the link to depression began.

As doctors started testing folate levels, they soon discovered a host of illnesses that were linked

to folate deficiency. Besides anemia, there was neuropathy, neurotube deficits, and dementia.

Psychiatrists tested folate at hospital admission and found that one in four patients had low levels,

particularly those with psychosis and depression.

Folate deficiency was particularly prevalent in people who did not respond to antidepressants,

and supplementation often brought those patients to remission.

There are at least two reasons why folate deficiency might cause depression.

One is that folate is necessary for the production of serotonin, dopamine, and norapherin.

The other is that when folate goes low, homocysteine goes high,

and elevated homocysteine is linked to depression and cognitive dysfunction, as well as heart disease.

Homocystine is rough on the vasculature, and elevated levels can cause heart disease and stroke.

Let's pause for a preview of the CME quiz for this episode.

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