Short sleep duration has been associated with increased digital time among adolescents [35] and social media overuse with poor sleep outcomes: (i) sleep disruption (melatonin suppression) and desynchronization of body clock–hormone imbalance and brain inflammation and lower levels of deep sleep, (ii) desensitization of the brain reward system (reward, focus and motivation), and (iii) exposure to light at night has also been associated with risk of depression [28,182,183]. This evidence concerns the gene CLOCK and major depressive disorder.