what how????
Mental illnesses are health conditions that involve changes in mood, emotion, thinking, and behaving. They are associated with mental distress and problems with social functioning. Developmental disorders generally appear at birth or during childhood and are diagnosed by the age of 18. While mental illness doesnt typically interfere with cognitive abilities, a developmental disorder may impact a persons ability to learn or to understand certain thoughts. Unlike mental illness, which can be successfully treated, developmental disorders are lifelong disabilities.