How does substence abuse affect people's mind and bodies?

In many ways: Substance abuse affect mental function , body function , social function . It cause directly mental illness of worsen the existing mental illness . Depending on the type of the drug of abuse , there are specific types of mental illness that range from anxiety to psychosis and dementia. From the medical point , nearly all the body organ- system can be affected . They can cause high morbidity an mortal.