By this time, scientists have not yet developed a biologically-based system of testing for mental illnesses such as a blood test for schizophrenia or screening for depression. Mental processes are proven to have some biological nature underneath as they are directly predetermined by the activity of human brain. However, it is not enough to study the neural activity in mentally ill patients that is why diagnosis and treatment of mental disorders are developing much slower than diagnosing of chronic conditions.
At the present moment, scientists use tools in genetic and neuroimaging to discover the biology of the mental disorders. Epigenetics is another science which can possibly provide the biological explanation to the emerging of mental illnesses as it defines the way genes are affected by environmental factors.
The biological causes of the mental illnesses depend on Genetic, biological and environmental factors. While it is clear how these factors influence emerging chronic diseases, the way how they affect mental health is still vague. Trying to identify biomarkers of mental disorders, scientists have achieved no more than the clues by this moment in research. Thus, medics have defined that certain genes linked to schizophrenia, brain abnormalities increase the risk of developing the post-traumatic stress disorder, and autism is linked to the poor connectivity between the different regions of the brain.
However, there are not enough tools to explain the nature of mental illnesses, and researchers are retained from incarnating their desire to explain abnormalities from the scientific point of view. Some scientists assume that there is no way all mental illnesses could be explained purely from the biological perspective.