From aiding in weight loss to helping keep your skin looking perfect, there are several ways that drinking water can benefit your body. Especially when it comes to your mental health.

According to a new small study, drinking plain water can boost your mental performance, however, that effect may only work sometimes. During the study, researchers found that participants who drank about three cups of water before taking a series of cognitive tests performed better on a test that measures reaction times compared to participants who did not drink any water. The results suggest that the sensation of being thirsty may distract people from performing a task at hand, while also delaying their response time.

Although water consumption may improve mental health in some tests, it does not always improve cognition. During a separate series of tests, researchers found that participants performed better if they did not drink water. It is not clear why water may have a positive effect in some cases and a negative effect in others.

Previous studies have suggested that water consumption can help children with memory and that dehydration can have a negative effect on mental performance, Experts say that further research should be conducted to determine why water has different effects in different cases.