Assessment of violence risk is important for the prevention of violent behavior. Some psychiatric diagnoses involve increased risk of violence. Schizophrenia, and especially the paranoid type, is the most important of these.
In a way, you're asking two questions, or rather, the same question about individuals and groups. We can predict rates of violent behavior in various groups rather well. Geir mentions the association between paranoid schizophrenia and violence, for example. Aside from psychiatric diagnosis and intoxication, there are also psychometric and demographic predictors of violence and suicidality. But when it comes to making strong predictions about individuals, our job gets a lot harder and error-prone. This is driven by the limited validity of our predictors and the low base rates for most serious forms of violence - an issue first recognized by Paul Meehl in the 1950s and fictionalized by Philip K. Dick in the short story that formed the basis for the movie, Minority Report. If, say, only 1 in 100 people is going to do something, then a predictor needs to be more than 99% accurate in order to improve on chance - which is a tall order. Never mind if the behavior occurs only in 1 per 10,000 people...
No, it's not possible to predict violent behavior of the patient.
It's difficult to tell when they get violent .
Actually I dont think wwe could predict the concrete behavior of the patient, however there are some clues, for instance we know that they are less aware from their own violent impulses and they often deny those feelings, so getting them in some sort of "insight" could be therapeutic
Really, (1) a careful clinical interview for the impulsive and aggressive symptoms, (2) application of psychological testing, particularly scales in the field of violence and aggression, and (3) the use of familial background of patient’s violence from professionals such as social worker may help to identify the risk of violence in inpatient and outpatient patients with schizophrenia.
Really, (1) a careful clinical interview for the impulsive and aggressive symptoms, (2) application of psychological testing, particularly scales in the field of violence and aggression, and (3) the use of familial background of patient’s violence from professionals such as social worker may help to identify the risk of violence in inpatient and outpatient patients with schizophrenia.
There are structured clinical tools available which can help assess the likelihood of a patient being violent, such as the HCR-20 which uses a number of historical, clinical and future risk factors. The presence/absence of the specific risk factors gives an indication of an individual's risk of violence, but not a prediction,
Case study method is the most accepted to explore individual and social background. In depth interaction with a schegophrenics it is possible to identify risk factors of violence. It can further be supplemented with available psychological tools as suggested by Victoria Hatchett. However, when and in which situation such an individual will become violent seems to be difficult to answer. At times even a small unimportant instance may trigger violent behaviour, whereas, big events may be ignored by the schigophrenic individual. No doubt one can gain lead from case study and psychological interventions to a great extent.
Schizophrenia (especially paranoid type) and non-paranoid schizophrenic psychosis increases the risk of violence with an odds ratio of four or more compared to the normal population. Psychosis as a whole is significantly associated with 50-70% increased risk of violence (Douglas et al. 2009). It is also important to know that mental illness as a whole does not provide any increase in risk. A variety of non-psychotic subjective states are associated with a lower risk of violence than in the average population (Douglas et al. 2009).
Douglas KS, Guy LS, Hart SD (2009) Psychosis as a risk factor for violence to others: a meta-analysis. Psychol Bull 135: 679 – 706. http://psycnet.apa.org/journals/bul/135/5/679/
In a way, you're asking two questions, or rather, the same question about individuals and groups. We can predict rates of violent behavior in various groups rather well. Geir mentions the association between paranoid schizophrenia and violence, for example. Aside from psychiatric diagnosis and intoxication, there are also psychometric and demographic predictors of violence and suicidality. But when it comes to making strong predictions about individuals, our job gets a lot harder and error-prone. This is driven by the limited validity of our predictors and the low base rates for most serious forms of violence - an issue first recognized by Paul Meehl in the 1950s and fictionalized by Philip K. Dick in the short story that formed the basis for the movie, Minority Report. If, say, only 1 in 100 people is going to do something, then a predictor needs to be more than 99% accurate in order to improve on chance - which is a tall order. Never mind if the behavior occurs only in 1 per 10,000 people...
I would contend that Stephen addressed the question pretty well. Not really if you are looking at doing so at the specific person level. This is because of the reason he described. The thing to remember about ratios is that they are really relative. If something occurs in the general population 1/1000000000 and another group has a incidence rate of 4/1000000000 they are 4 times more likely, but still a pretty hard to predict group.
With the proviso that there are circumstances under which we can predict well in the short term. For example: the patient's brow is set in fear, his mouth in a snarl, and his hands are making chopping motions as heyells strange curses at you and advances...
... love Philip K. Dick :D
So, given that an exact prediction is discarded, I think is of much better to learn how to (try to) control/heal/work with a patient that is actually violent, then my above comment on increase his/her conscience about his/her impulses...
I suggest a recent study indicating some limitations on researches on violence and Schizophrenia. The paper is available free acess via pubmed or researchgate
Tilman Steinert and Karen Hamann External Validity of Studies on Aggressive Behavior in Patients with Schizophrenia: Systematic Review, Clinical Practice and Epidemiology in Mental Health, 2012; 8: Pp. 74-80.
Studies on violence in schizophrenia use two different approaches: use of epidemiological data, and clinical studies recording direct patient data after gaining informed consent. With regard to informed consent requiring agreement and cooperation, the question arises as to what extent participants represent patients with schizophrenia and violent behaviour (external validity). We conducted a systematic literature research. In most of the studies, aggression or violence, respectively, were poorly defined. Only 5 (15.2%) studies used a cut-off score on an aggression scale. Only 6 studies (18.2%) reported the number of patients who refused to participate, and 16 (48.5%) reported the number of drop-outs. Only 3 studies (9.1%) reported a systematic comparison of participants and non-participants. We found that data which allow for the assessment of representativeness of the investigated samples are poorly reported. For most studies, doubts regarding external validity seem justified and generalisability is questionable due to possible selection bias.
A very simple and reasonable question that has a complex answer.
We are reasonable at assigning people to categories of risk that are reliable [actuarial methods]. The major issue is how you apply this group data to an individual. Knowing they are at, say, 30% risk of re-offending in the next 5-7 years tells us little as clinicians what to do now. Nor does it tell us if a particular person is in the 30% who will re offend to the 70% who will not.
For these reasons, tools which provide greater clinical utility such as the HCR 20, the START and the SAPROF which guide clinicians in to more clinically relevant risk assessment and risk formulation are of much greater value. They assess much ore than historical factors and provide a focus for treatment intervention and the ability to measure change. The ideographic [the person's particular story and pattern of violence] can also fit well with such tools.
None of this is predictive in the clinical setting. It is about assessing who is at most risk and in what way, and helping them diminish that risk. This is the ethical basis for clinical risk assessment, even for low base rate outcomes[ such as homicide and suicide].
Allnutt et al Managing aggression and violence: the clinician's role in contemporary mental health care. Australian and New Zealand Journal of Psychiatry DOI: 10.1177/0004867413484368 is a helpful recent summary of the clinical aspects of this question.
Most likely if comand hallucinations from "God" or Delusions of grandeur or of persecution
Well, yes, but the literature around acting on delusions and command hallucinations is less robust than one would imagine. We are working on a rating tool to differentiate motivations for violence amongst people with a psychotic illness. Kappa of 0.86 for it so it does appear to have inter-rater reliability [just presented this as a poster at the IAFMHS meeting in Maastricht last week]. See also our recent review:
Penney S, Morgan A and Simpson A I F. Motivational Influences in Persons Found Not Criminally Responsible on Account of Mental Disorder: A Review of Legislation and Research. Behavioral Sciences and the Law, 2013, DOI: 10.1002/bsl.2067.
Going back to the original question, I would also add that the impact of schizophrenia on risk of violence depends on the reference population. Compared to the general population, there is an elevated risk of violence among individuals with schizophrenia, particularly in combination with substance use.
But once violent, offenders with schizophrenia are actually LOWER risk to commit more violence than offenders who do not have schizophrenia.
This literature is nicely summarized in multiple sources, including my colleagues' book on Violent Offenders
http://www.apa.org/pubs/books/4317363.aspx
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