The link between having mental health problems and violence is widely assumed. The portrayal of this in the media encourages this assumption further. Many believe, much like I did before research, those who suffer from mental illnesses including schizophrenia, bipolar disorder, depression and anxiety are more likely to become violent individuals with a tendency to commit serious crimes such as homicide, theft and assault. There is minimal evidence to support this yet a 2006 national survey found that 60% of Americans believe those with schizophrenia will be more violent than those not affected and 32% believed those with depression would be more violent than those seen as mentally stable. (http://www.health.harvard.edu/newsletter_article/mental-illness-and-violence)
Within mass media, stories of crimes committed by those with mental health issues are typically more of a story and a concern than crimes committed by others. Research has shown many people get their degrading perceptions of mentally ill people from the media (http://ontario.cmha.ca/files/2012/07/olm_stigma_matters_200902.pdf). The media tends to exaggerate and stereotype individuals with mental health issues, an example is one of the most iconic thrillers to hit the screens, 'psycho', the main character having a personality disorder and therefore goes on to commit murder when in reality, an extremely low percentage of those with disorders, including sever mental illnesses, commit serious offences. Another way in which the media create and encourage the stigma related to those with mental health issues is the way they focus mainly on the fact of the individual's mental health history—for example, "1,200 killed by mental patients" (The Sun, 07/10/2013). In subtler cases it may just be improper language to make terms sound demeaning, such as referring to those with personality disorders as 'psychotic'. Another factor which causes stigma with mental health is the historical religious view in which those affected by mental illness were deemed to be possessed by demons, a belief that still persists in some cultures. Although throughout time it is a factor affecting stigma in a significantly decreasing amount, it is still mentioned, especially in highly religious households due to the fact that the bible includes demeaning passages showing discrimination. An example of this is "he acted like a madman, making marks on the doors of the gate and letting saliva run down his beard. Achish said to his servants, “Look at the man! He is insane! " (Sam. 21:12-15)
It is often assumed that individuals who carry out severe crimes, such as school shootings in America, are mentally ill, even without proper psychiatric tests. It is rare that the verdict of crime is "not guilty by reason of insanity" meaning even those who do suffer with psychological issues, there is not always a direct link with the illness and the crime. Other factors are often involved, especially substance abuse and financial difficulties. In fact, according to the American psychological association, in a study of crimes committed by those with serious mental illnesses, only 7.5% were linked directly to the symptoms of mental illness.(http://www.apa.org/news/press/releases/2014/04/mental-illness-crime.aspx) In a study of 429 crimes committed by 143 of people affected by some sort of mental illness, only 3% of crimes showed direct links to symptoms of depression, 4% to schizophrenia and 10% to bipolar disorder so even those with a mental health condition commit crimes for reasons other than their illness.
In fact, those with a serious mental health issue are more a danger to themselves than to others. The percentage of those with a mental illness committing serious offences is relatively low and the majority of serious offences such as homicide are committed by people who are not affected. It is more common for those under the influence of drugs and alcohol to commit a crime than those affected with mental illness. 37% of offenders are intoxicated at the time the crime was committed, this is out of just under 2 million offenders still in prison. (https://www.ncadd.org/about-addiction/alcohol-drugs-and-crime) The rates of homicide carried out by mentally ill offenders has stayed at a constant level since the 90's, there is no evidence to support the often publicised claim that it is on the rise. Some of those who are affected by a serious mental illness and also commit serious crimes claim that they were not in touch with reality at the specific time of the crime since serious mental health complaints can cause hallucinations. However, usually if the illness gets to this severity it is treated before the individual affected offends. it is claimed that most trained psychologists can determine the signs of a possible offender and resolve the issue before any crime is committed. (https://thepsychologist.bps.org.uk/volume-14/edition-4/crime-prevention-0)
Those affected by mental health conditions are often stereotyped and stigmatised as a group. A prime example of this is the 'Germanwings Flight 9525' where Andreas Lubitz purposely crashed a plane full of passengers into a mountain, killing many in the process. He was believed to have been suffering with severe depression and it is assumed by investigators that crashing the plane was his way of suicide. Lubitz received some care—such as medication—however his treatment was poor and not a single doctor informed the airline that he should not be able to pilot a plane. As a result of this tragic event, some questioned whether pilots with any history of depression should be able to fly. Therefore, since one individual carried out this unforgivable act, people assume that everybody with the same illness will act in a similar negative way—even when the illness is not confirmed.
Violent crime statistics show that only 1% of victims believe the crime happened because the perpetrator had a mental illness (http://www.time-to-change.org.uk/news-media/media-advisory-service/help-journalists/violence-mental-health-problems). This shows those committing a crime due to direct links with their illness is in the minority. It is difficult to determine exactly why the public believe those with mental health problems are violent, dangerous criminals when the evidence points in the opposite direction. Of course, there are some individuals affected by mental illnesses who do commit violent crimes, yet they pose no more of a threat than anybody else. In fact they are more often the victims of violence than the perpetrators as they are generally very vulnerable people that others tend to exploit. So remember the next time somebody stereotypes somebody affected with a mental health issue as violent and dangerous, they are more than likely not. It is a widely recognised assumption, not helped by portrayal in the media.
To conclude, it is a myth that those with serious mental illnesses are any more likely to commit crimes in comparison to the general population. If there is a link it's the other way round— people with mental health problems are more likely to be the victims of violent crimes than the perpetrators.