Education, including in design, is at a crossroads with the rise of generative artificial intelligence (GenAI). Although its use is exponentially growing, there are concerns that its unreflective use may undermine the development of essential skills. Regarding creativity-specific contexts, its potential to either enhance or constrain cognitive processes and creative confidence remains underexplored. This study investigates ChatGPT’s impact on ideation among User Experience Design students (N = 35), focusing on their cognitive processes, creative confidence and idea creativity. In a within-group experiment, participants generated a total of 214 design concepts under conditions with and without ChatGPT. Data collected included pre-experiment self-report of ChatGPT usage, creative confidence measures, artifacts (sketches, collages, mind maps), experts’ assessment of creativity and post-experiment self-report on creative confidence, ideas and ideation process, along with interviews. Findings indicate that while ChatGPT enhanced convenience and speed, it was associated with dampened cognitive engagement, which may result in an increased reliance on the tool and possible decreased creative confidence, potentially triggering a cycle of dependency and reduced self-efficacy, warranting further longitudinal investigation. We finalize this article with recommendations for design education to integrate metacognitive training and encourage critical evaluation of AI use, thereby empowering novice designers as active, reflective creative thinkers.