Homicidal ideation
Homicidal ideation is a common medical term for thoughts about homicide. There is a range of homicidal thoughts which spans from vague and fleeting to detailed and fully formulated plans without the act itself. Most people who have homicidal ideation do not commit homicide. 50–91% of people surveyed on university grounds in various places in the United States admit to having had a homicidal fantasy. Homicidal ideation accounts for 10–17% of patient presentations to psychiatric facilities in the United States.
Homicidal ideation is not a disease itself, but may result from other illnesses such as delirium and psychosis. Psychosis, which accounts for 89% of admissions with homicidal ideation in one US study, includes substance-induced psychosis and the psychoses related to schizophreniform disorder and schizophrenia. Delirium is often drug induced or secondary to general medical illness.
It may arise in association with personality disorders or it may occur in people who do not have any detectable illness. In fact, surveys have shown that the majority of people have had homicidal fantasies at some stage in their life. Many theories have been proposed to explain this.
Diagnosis
Violence risk
There are many associated risk factors which include a history of violence, thoughts of committing harm, poor impulse control and an inability to delay gratification.Associated psychopathology
People who have homicidal ideation are at higher risk of other psychopathology than the normal population. This includes suicidal ideation, psychosis, delirium, or intoxication.Homicidal ideation may arise in relation to behavioural conditions such as personality disorder. A study in Finland showed an increased risk of violence from people who have antisocial personality disorder, which is greater than the risk of violence from people who have schizophrenia. The same study also cites that many other mental disorders are not associated with an increased risk of violence, of note: depression, anxiety disorders and intellectual disability.
Homicidal ideation may arise in people who are otherwise quite well, as is demonstrated by the fact that the greater majority of people within the general population have had homicidal fantasies. When triggering factors are sought regarding homicidal fantasies the majority seem to be linked in some way to the disruption of a couple relationship. Either jealousy or revenge, greed/lust or even fear and self-defense prompt homicidal thoughts and actions in the majority of cases. In a minority of cases, homicides and acts of violence may be related to mental disorder. These homicides and fantasies do not seem to have the same underlying triggers as those by people without a mental disorder, but when these trigger factors are present the risk for violence is greater than usual.
People who present with homicidal ideation also have a higher risk of suicide. This shows the need for an assessment of suicide risk in people with thoughts of violence towards others.