In 2009, Gruzelier conducted a study to examine the effects of beta brainwave entrainment on mood improvement. Beta brainwaves are associated with alertness and concentration, and the study aimed to determine whether stimulating these brainwaves could enhance mood. The study involved participants undergoing sessions of beta brainwave entrainment and reporting on their mood states before and after the sessions.

The results showed a significant improvement in reported mood states after the sessions, suggesting that beta brainwave entrainment could be an effective method for improving mood. This study provides evidence that beta brainwave entrainment could potentially be used as a non-invasive, non-pharmaceutical treatment for mood disorders. In conclusion, Gruzelier’s 2009 study provides promising evidence for the use of beta brainwave entrainment in mood improvement, but further research is needed to fully understand the potential benefits and limitations of this approach.