This story reported a study that showed an amino acid called acetyl-L-carnitine (LAC) is lower in people with clinical depression, suggesting it might be used as a biomarker to guide treatment decisions.
We applaud the story’s generally cautious tone and detailed description of the study. However, parts of the story might confuse readers by suggesting a benefit to taking LAC for depression even though, as the story points out, there’s as yet no evidence that LAC can effectively treat depression.
Also, the story could have broadened its perspective by including comments from independent sources and data on societal costs of depression versus the potential cost of biomarker testing and treatment with LAC.
A biomarker could be a useful tool to develop treatments for depression or to target those at risk for early diagnosis and interventions. However, news stories have to maintain a cautious tone because identifying appropriate biomarkers and translating them to patient care is a complex process.
Because of the early stage of this research, we’ll rate this N/A.
But it’s worth noting that a new test used in the diagnostic process would have an enormous cost to the health care system potentially. However, if the test in turn allowed more targeted and efficacious treatment, it could lower health care and productivity costs due to the illness.
We’re rating this N/A because the study itself didn’t make any claims of benefit, only that they found an association between low levels of LAC and depressive symptoms. (No one was treated with LAC to see if it helped.) The story could have been a bit clearer on the measurements (how stark were the differences b/w healthy and depressed people) and provided more data, but we didn’t feel it was necessary here.
As with any screening test, there is the risk of false-positives and false-negatives. The story didn’t discuss this, especially as a hurdle the researchers will face when they test this concept on larger groups of people.
The story provided important caveats about the study including that it did not test whether LAC can be used to treat depression, and that other studies linking LAC to improvements in depression were too small to be conclusive.
It quoted a researcher stating: “We are at the very beginning of this discovery and can’t recommend people to buy this supplement at the GNC store.”
However, some statements — such as the suggestion that “correcting a deficiency in LAC could be a step toward more targeted treatments of depression, especially for those who suffered childhood trauma or began having depression at an early age” — could lead some readers to try LAC on their own despite any cautions.
Also, the story could have noted a couple of other caveats mentioned in the study. For one, larger studies are needed to determine whether low LAC is specific to depression, since many people with depression have other mood disorders such as bipolar disorder or anxiety disorder.
Second, it’s unclear whether low LAC is a stable trait of people prone to depression, or if it’s only present in people in the throes of a depressive episode, like those in the study. A stable trait biomarker might help with early diagnosis and intervention.
The story called depression “among the leading causes of disability worldwide, with more than 300 million people suffering from this mental illness, according to the World Health Organization.” While this is higher than some estimates, we don’t consider it disease mongering. However, the story could have emphasized that not all people with depression show a change in this biomarker.
We applaud the story’s acknowledgment of the complexity of depression, mentioning that it’s “not a single disease but a variety of feelings and behaviors that may have different underlying causes.”
As far as we could tell, there were no undisclosed conflicts of interest.
However, the story’s had no independent sources, which makes this not satisfactory.
The story didn’t explain how severe depression is usually diagnosed, and that there are some treatments available.
The story made it clear that the blood test is not yet available.
The story described the study as “the first confirmation of the results from animal studies” that LAC is lower in people with depression than people who are not depressed.
The story did not rely exclusively on a buoyant Stanford University news release.
That news release irresponsibly stated in its second paragraph that LAC is “widely available in drugstores, supermarkets and health food catalogs as a nutritional supplement. People with severe or treatment-resistant depression, or whose bouts of depression began earlier in life, have particularly low blood levels of the substance.”
To us, that appears to be a thinly veiled suggestion that people with depression self-medicate by taking LAC, contradicting the caution of the study’s authors that there’s as yet no evidence that LAC can treat depression.