tAVNS for Stress Reduction in University Students

The goal of this clinical trial is to learn if transcutaneous auricular vagus nerve stimulation (taVNS) works to reduce perceived stress and psychological distress in university students with high distress levels. The main questions it aims to answer are: * Does taVNS reduce perceived stress (measured by PSS-10) in university students with high psychological distress? * Does taVNS reduce psychological distress (measured by K10) in university students with high psychological distress? * Is the intervention feasible and tolerable for implementation in higher-education mental health support? Researchers will compare taVNS (electrode placed on the left tragus) to a sham stimulation group (electrode placed on the left earlobe) to see if taVNS reduces stress and distress. Participants will: * Attend five consecutive daily 30-minute stimulation sessions * Complete stress and distress questionnaires before the intervention, immediately after, and at 1-month follow-up * Receive electrical stimulation at individually adjusted intensity using the Nurosym device (pulse width 250 µs, frequency 20 Hz).