Creatine: From the Gym to Mental Health
Creatine has built a strong reputation in the fitness world. For years, athletes and gym-goers have used it to support strength and muscle growth. Creatine is among the most studied sports supplements out there, with extensive research investigating its ability to help muscles generate energy for intense exercise.
However, what very few people know is that our brain requires a tremendous amount of energy every single day. Researchers have known for a long time about the function of creatine in this process. That has raised an important question: Could the same supplement used in the weight room also help people living with depression?
Systematic Review: An In-Depth Analysis of Five Trials
A new systematic review explored that possibility by analyzing six published reports covering five randomized controlled trials. In these studies, neither the participants nor the doctors knew who received creatine and who received a placebo. The trials took place in South Korea, the United States, Brazil, Israel, and India, involving 238 participants at the start of the studies. Of those, 126 received creatine and 112 received a placebo. The average participant was 36 years old. Most were women, and two studies included only women. Four experiments concerned major depressive disorder, and one was on depressed states occurring during bipolar disorder.
Results That Point in Different Directions
The findings were far from clear-cut. Two of the five trials reported encouraging results. Both came from the same study involving women with major depressive disorder. Participants who took five grams of creatine daily alongside the antidepressant escitalopram experienced a greater reduction in depressive symptoms after eight weeks than those who received a placebo. The improvement was large, with a Cohen's d of 1.13 on the Hamilton Depression Rating Scale, and more women reached remission. Another trial found that combining creatine with cognitive behavioral therapy reduced symptoms more than therapy paired with a placebo.
The remaining three trials told a different story. One found no benefit from taking either five or ten grams of creatine daily in people whose depression had not responded to medication. Another reported no improvement among adolescent girls receiving different doses of creatine. A fifth study also found no benefit in people with bipolar disorder during a depressive episode. Two participants with bipolar disorder who received creatine developed hypomania or mania, suggesting that the supplement may affect different mental health conditions in different ways.
Why Scientists Became Interested
The brain consumes about 20 percent of the body's energy despite making up only a small share of its total weight. Every nerve cell depends on adenosine triphosphate (ATP) to function, and creatine helps restore ATP after it is used. Scientists have found changes in brain creatine metabolism in people with mood disorders, hinting that problems with energy production could contribute to depression. Creatine may also influence dopamine and serotonin, two brain chemicals involved in mood that are already targeted by many antidepressant medications.
Conclusion: More Research Needed
Even so, the current evidence does not show that low brain creatine causes depression. The relationship remains a correlation rather than proof of cause and effect. “The signal is interesting, but it is not a verdict,” said Bassam Jeryous Fares, first author of the review and a student in the Faculty of Medicine at the University of Ottawa. “Two trials pointed one way and three pointed another. That is not the kind of evidence on which you change clinical practice. It is the kind that tells you the question is worth further exploration.” Nicholas Fabiano, corresponding author and a psychiatry resident at the University of Ottawa, also urged caution. “Creatine appears to be a safe intervention. The adverse events we found were limited to mild gastrointestinal discomfort. We cannot yet reliably say that creatine helps with depressive symptoms or if the findings are generalizable to everyone.”
The review highlights several limitations: the clinical trials were small, the participants were not evenly split by gender, and only two studies were judged to have a low risk of bias. The researchers say larger studies are needed, especially those lasting longer than eight weeks. They also want to see studies that examine creatine alongside exercise and investigate different doses while recognizing that higher amounts are not always better. Animal research has also hinted that creatine may affect males and females differently, which could help explain why studies involving more women produced stronger results. For now, creatine remains a supplement with proven benefits for muscle performance and an intriguing, but unproven, possibility for treating depression. Science is moving forward, but the evidence is not yet strong enough to change how depression is treated.