The causes of mental illness can be complicating and diverse. A lot of mental illnesses are caused by biological, environmental, and psychological factors.
In the brain the there are special chemicals these are called neurotransmitters. The purpose of these neurotransmitters is to assist the brain's nerve cells to communicate together.
When the neurotransmitters are not balanced or not functioning properly, messages might not travel to the brain in the correct manner, as of result of this mental illness symptoms develop.
There are some infections which are connected to mental illness development, worsening of mental disorder symptoms and brain damage.
For example scientists at Columbia University in 2006 stated that as much one fifth of schizophrenia cases occur because of prenatal infections.
Bipolar disorder, ocd (obsessive-compulsive disorder) and autism have been connected to parasitic, viral and bacterial infections.
Numerous mental disorders run in families, which suggest that it is passed from parental genes to the children's genes.
Numerous scientists and doctors believe lots of mental illnesses are connected to irregularities in multiple genes rather than just one. This would explain why someone would inherit the susceptibility but not necessarily develop the condition.
However interaction of the genes and environmental stressors and psychological trauma can trigger or influence the mental illiness in a person who has inherited susceptibility to the disorder.