Despite evidence that TUS can increase positive mood in humans, it has yet to be investigated whether TUS can increase positive mood in humans who are experiencing chronic low mood or depression. The present study will, for the first time, examine whether TUS can improve depressive symptoms. Twenty to thirty participants with mild to moderate depressive symptoms (Beck Depression Inventory Score between 10 and 25) will be randomly assigned to a TUS sham or TUS activation condition. In the TUS activation condition, TUS will be used to stimulate the right fronto-temporal area, which has previously been shown to increase positive mood. Participants in the TUS sham condition will not receive any brain stimulation. Participants will attend five sessions within seven days or ten sessions within fourteen days. At each session, in addition to brain stimulation, self-reported mood and depressive symptoms will be recorded. Furthermore, the investigators will use electroencephalogram (EEG) to record changes in brain electrical signals during TUS stimulation. Based on prior research, the investigators predict that mood will increase and depressive symptoms will decrease with TUS stimulation.