Aims: This study aims to evaluate the effects of transcutaneous auricular vagus nerve stimulation (taVNS) on sustained attention and depression in individuals with suspected attention deficit hyperactivity disorder (ADHD). Methods: Between May 1, 2022 and September 25, 2022, the study included 60 students (9 males, 51 females; mean age: 21.11±1.6 years; range, 18 to 24 years) identified as being at high risk for attention deficit hyperactivity disorder (ADHD). Participants were randomly assigned to either the intervention or control groups. Each group consisted of 30 individuals. The intervention group received taVNS in conjunction with mobile-assisted games and relaxation exercises, while the control group received mobile-assisted games and relaxation exercises alone. The data were collected using a descriptive information form, the Beck Depression Inventory, and mobile-assisted assessment parameters. Data were analyzed using the Wilcoxon signed-rank test, t-test, and Mann-Whitney U test. Results: Significant differences were observed in the intervention group concerning the sub-parameters used to measure attention and depression scale scores; however, in the control group, all but one of the attention sub-parameters showed significant differences. A comparison between the two groups revealed significant differences in reaction times and Beck Depression Inventory scores in favor of the intervention group. Conclusion: This study revealed that taVNS can effectively improve attention (cognitive function) and alleviate symptoms of depression.