Risk+Factors+for+Mental+Illnesses

Although scientists at this time do not know the causes of mental illnesses, they have identified factors that put individuals at risk. Some of these factors are environmental, some are genetic, and some are social. In fact, all these factors most likely combine to influence whether someone becomes mentally ill. Genetic, environmental, and social factors interact to influence whether someone becomes mentally ill. Environmental factors such as head injury, poor nutrition, and exposure to toxins (including lead and tobacco smoke) can increase the likelihood of developing a mental illness.-- Genes also play a role in determining whether someone develops a mental illness. The illnesses that are most likely to have a genetic component include autism, bipolar disorder, schizophrenia, and ADHD. For example, the observation that children with ADHD are much more likely to have a sibling or parent with ADHD supports a role for genetics in determining whether someone is at risk for ADHD. In studies of twins, ADHD is significantly more likely to be present in an identical twin than a fraternal twin. The same can be said for schizophrenia and depression. Mental illnesses are not triggered by a change in a single gene; scientists believe that the interaction of several genes may trigger mental illness. Furthermore, the combination of genetic, environmental, and social factors might determine whether a case of mental illness is mild or severe.

Social factors also present risks and can harm an individual’s, especially a child’s, mental health. Well researched and widely accepted social factors include http://science.education.nih.gov/Supplements/Nih5/Mental/guide/info-mental-b.htm#causes
 * severe parental discord,
 * death of a family member or close friend,
 * parent’s mental illness,
 * parent’s criminality,
 * overcrowding,
 * economic hardship,
 * abuse,
 * neglect, and
 * exposure to violence.