Neurodevelopmental disorders are a group of disorders that affect the development of the nervous system, leading to abnormal brain function  which may affect emotion, learning ability, self-control, and memory. The effects of neurodevelopmental disorders tend to last for a person's lifetime. Neurodevelopmental disorders result when complex genetic and environmental factors come together to change brain development. In some cases, we know what those genetic and environmental factors are. In many cases, we do not. Neurodevelopmental disorders tend to run in families. The father might have a learning disability and his son might have ADHD. A brother might have DLD and his sister might have autism. This suggests that some neurodevelopmental disorders have common causes. No one has identified the exact causes of the brain dysfunctions that lead to DLD, although researchers are working on this question. Of course, everyone’s brain is different from everyone else’s brain. For this reason, it is important to consider how much the problem interferes with social, academic, or occupational success before diagnosing DLD.