Twenty percent of children and adolescents experience mental health disorders—an unsurprising figure considering that half of all mental illnesses begin by the age of 14 and three-quarters by the mid-20s. What's more, children with complex medical conditions are more likely to suffer psychological disorders than those without. In fact, evidence suggests that 58% of children with a medical condition experience mental health disorders, and that having one has a negative impact on quality-of-life over time.