lt;.001), and health anxiety positively affected HRIU with medium effect from Wave 2 to Wave 3 (β=.11; P=.03). Conclusions: Adolescents with lower, rather than high, health anxiety are susceptible to the negative long-term effects of HRIU. For adolescents with high health anxiety, HRIU neither worsens nor relieves health anxiety over time, suggesting that counselors should recommend other coping strategies besides HRIU. Adolescents with medium to low health anxiety should be guided toward mindful HRIU to prevent increased health anxiety after HRIU. This includes fostering eHealth literacy (eg, recognizing personally irrelevant information and awareness of sensationalism in media) and coping mechanisms (eg, time or topic limits, or intentional rather than compulsive searching).