People experiencing symptoms of psychosis are not necessarily dangerous; in fact, patients suffering from severe mental illness can be more likely to become victims of violence. Psychotic people develop a break from reality because of an underlying mental health condition or a bad reaction to medication. They can experience hallucinations and delusions that lead them to believe they are under attack or are not living in reality. Many, however, are not dangerous, and in psychotic people with an increased tendency to behave dangerously, the primary risk may be to themselves, rather than others.
The belief that psychosis and other severe symptoms of mental illness lead to violence is a widespread stereotype. Research on the incidence of violence in the general population suggests that individuals with mental illness are not, as a whole, more likely to commit violence. Among psychotic people, there is a small increase in the incidence of violence committed by those with positive symptoms like delusions and hallucinations. Much of this violence is against property, rather than people.
For patients with psychosis, behavior that appears dangerous and irrational could be an entirely reasonable response to delusions and hallucinations. Patients who genuinely believe they are being tracked by law enforcement or assaulted by doctors, for example, may react violently if they feel cornered or threatened. An intervention could turn bad in these circumstances.
Studies on psychotic people also illustrate that extra-clinical factors may play a role in expressions of violence and dangerous activities. Severe mental illness can increase the risk of homelessness, adverse police interactions, and limited access to education. Stress created through these circumstances can increase the incidence of violence. Researchers also point to a self-fulfilling prophecy phenomenon; police responding to a call about a psychotic person may believe the patient is dangerous, and the patient may react violently if the police behave in a way that appears threatening.
A patient's mental health status can have an influence on the likelihood for violent behavior. Patients who cannot access regular mental health care including medications, psychotherapy, and community support like housing can be more dangerous than those who receive stable treatment and support. Programs to address concerns about violent crime and mental illness tend to focus on provision of mental health services to help patients manage their mental illnesses effectively in recognition of this fact.
In a study conducted in 2005, Northwestern University researcher Linda A. Teplin noted that incidences of violence committed against people with mental illness were much higher than those in the general population. For people with severe psychosis, the incidence can be 12 times or even higher than for those without mental health conditions. This research suggests that psychotic people are more likely to be victims than perpetrators of dangerous acts.