<unk>  have been strongly associated.<unk>  is known to harm the health of people with<unk> , and to negatively affect their cognition. Studies across 20 countries showed that people with<unk>  were much more likely to smoke than those without this diagnosis. For example, in the United States, 90% or more of people with<unk>  smoked, compared to 20% of the general population in 2006. Though it is well established that<unk>  is more prevalent among people with<unk>  than the general population as well as those with other psychiatric diagnoses, there is currently no definitive explanation for this difference. Many social, psychological, and biological explanations have been proposed, but today research focuses on neurobiology. Increased rates of<unk>  among people with<unk>  have a number of serious impacts, including increased rates of mortality, increased risks of suicidal behavior and cardiovascular disease, reduced treatment effectiveness, and greater financial hardship. Studies have also shown that in a male population, having a<unk>  spectrum disorder puts a patient at risk of excess<unk>  use. As a result, researchers believe it is important for mental health professionals to combat<unk>  among people with<unk> .
Schizophrenia and tobacco smoking
Old age and driving
MMR vaccine and autism
Post-traumatic stress disorder and substance use disorders
Alcohol and breast cancer
Alcohol and cardiovascular disease
First Nations and diabetes
Circumcision and HIV