What if the best new treatment for depression was already available on the shelves of any drug store? This could improve patients’ access to treatment. New studies show that this might be reality. New research shows the potential of Acetyl L-Cartinine to change how we treat depression. It found decreased levels of LAC in depressed people. The levels were related to severity of depression and treatment resistance. LAC created long-lasting effects in depressed mice.
What if there was a blood test to pinpoint what is causing depression? Or a way to test which antidepressant would work for somebody? To make this possible, researchers must identify biomarkers for depression. Biomarkers are things you can measure in the body. They can show that show that somebody has a particular disease. For example, blood sugar is a biomarker for diabetes. They can also show that has been exposed to something in the environment. For example, blood concentration of lead shows lead exposure.
Biomarkers are useful for many things.
- developing new tests to diagnose disease
- determining the best treatment option
- developing new drugs
Researchers are trying to find good biomarkers for depression. However, they have found few reliable ones. This study shows that Acetyl-L-Cartinine (LAC) deficiency may be a good biomarker for depression.
The body already creates LAC, which is important for the brain to use fat and energy correctly. It also helps the hippocampus work to regulate mood. It is also readily available as a dietary supplement. It also has fewer side effects than antidepressants. Although this and other studies look at how it is related to depression, we still don’t know if it’s an effective antidepressant. This study looked at LAC levels in people who have been diagnosed with major depressive disorder. Major depressive disorder is commonly known as depression or clinical depression.
The researchers measured the LAC levels in depressed mice. They were lower in the depressed mice in the plasma and in two regions which regulate mood. Those regions are called the hippocampus and the prefrontal cortex. Mice with lower levels of LAC also had insulin resistance, which is related to diabetes. Then, the researchers gave the mice LAC. They became less depressed. They took longer to give up in the forced swim tests. The LAC only took 3 days to start working. Normally, antidepressants take weeks to work. The drug worked for 14 days after they stopped giving it to the mice, which is long for an antidepressant.
The researchers compared the LAC levels of people with and without depression. A total of 116 people participated in this study. The study was conducted at two different study sites. They used two different methods to assess LAC levels.
They matched the people by age and sex. Age and sex matching means that the researchers choose controls and subjects so that they fall into similar age and sex groups. Let’s say one in ten participants with depression are women who are between 40 and 50 years old. Then, one in ten of the healthy controls should be women between 40 and 50 years old.
Depressed people also had much lower LAC levels. People who were not taking medication had similar LAC levels to those who were not. Some groups had lower LAC levels:
- People with treatment-resistant depression (whose depression didn’t respond to medication)
- People with early-onset depression (who first became depressed at a young age)
- People who experienced childhood trauma, especially women who were neglected as children
This study is useful for many reasons. It is the first published study on LAC and major depressive disorder. Researchers have not found a good biomarker for depression. Biomarkers are things you can measure in the body that show that somebody has a particular disease or has been exposed to something in the environment. Biomarkers are useful for diagnosing and studying diseases. For example, blood sugar is a biomarker for diabetes. Also, LAC might be a useful therapy for depression and could be the “drug of the future”.
Limitations
- LAC levels might be lower when people do unhealthy behaviors. They might be related to sleep, diet, and exercise.
- This study only looked at people who are currently depressed (in a depressive episode). We are not sure if these people always have low LAC levels or if the LAC levels fall when they are depressed.
Citation
Nasca, Carla, et al. “Acetyl-l-carnitine deficiency in patients with major depressive disorder.” Proceedings of the National Academy of Sciences (2018): 201801609.
