The Impact of Evening Gaming on Cortisol and Melatonin Levels: Findings from a Randomized Controlled Trial

Video games (VGs) are a popular form of entertainment, especially among younger individuals, yet their impact on sleep-related hormonal regulation remains unclear. This randomized controlled trial investigated the effects of evening gaming on cortisol and melatonin—key hormones in the sleep-wake cycle—compared to watching a nature film. Thirty-one male participants (aged 18–37) completed two conditions: 120 minutes of gaming ("League of Legends" or "Counter-Strike: Global Offensive") and 120 minutes of watching a nature film. Salivary samples were collected pre- and post-session and at waking (+15- and +30-minutes post-waking) the next morning. Cortisol levels showed significant within-condition changes, but no significant differences between conditions were found (t(180.0) = 1.41, p = 0.16). The cortisol awakening response (CAR) increased 15 minutes post-waking and normalized by 30 minutes. Melatonin levels and the Area Under the Curve for Inhibition (AUCI) analysis for both hormones showed no significant differences between gaming and film. These findings suggest that evening gaming among regular gamers, under controlled conditions, does not disrupt hormonal balance compared to passive film-watching. Habituation to gaming and environmental controls may have mitigated stress responses. Future research should investigate the effects of game novelty, varying player experiences, and diverse populations to develop guidelines for healthy gaming practices. VG = video games; SCN = Suprachiasmatic Nucleus; HPA = Hypothalamic-Pituitary-Adrenal (Axis); CAR = Cortisol Awaking Response; AUCI = Area Under the Curve for Inhibition; BMI = Body Mass Index; adc = active digital condition pdc = passive digital condition; IGD = Internet Gaming Disorder