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Assessing Dangerousness: Myths and Research

Ronald Schouten, MD, JDAssociate Professor of Psychiatry

Harvard Medical SchoolDirector, Law & Psychiatry Service

Massachusetts General Hospital

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Overview• How we perceive risk and make decisions• What do we know about violence?• Some specific issues in risk assessment

– Domestic violence– Stalking– Public figures

• Assessing the evidence– Clinician/expert testimony – Screening instruments– Methodology

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Risk

Risk = Likelihood x Severity of consequences

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How We Make Decisions About Risk (and everything else)

• Experiential system: Knowing it– Reflexive: “Hair on the back of the neck” test.– Rapid– Effortless– Often not conscious:

• I just know it.

• But can you explain it?

– Affect driven

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How We Make Decisions About Risk

• Analytic system: Knowing about it– Slow– Algorithmic– Based on normative rules

• Probability calculus

• Data-based risk assessment

• Formal logic

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How We Make Decisions: Heuristics

• Emotions make a difference: The Affective Heuristic: – Fear/dread of event correlates with level of risk and

perceived probability, e.g. sex offenders– Risk/benefit analysis: Perceived benefit is inversely

related to perceived risk, and vice versa– Familiarity:

• People overestimate the risk of events that are unfamiliar and that they cannot control

• Ex: Health care workers and SARS

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How We Make Decisions: Heuristics

• Availability heuristic: similar events that have occurred within recent memory are seen as more likely to occur

• Geographic proximity/identification with victims• Probability neglect:

– When strong emotions are involved, we tend to focus on the severity of the outcome, rather than the probability that the outcome will occur

– We tend to overestimate the likelihood of low probability events, and underestimate the likelihood of higher probability events

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How We Make Decisions: Biases

• Extremeness aversion• Presentation bias:

– Proportions and absolute numbers convey more risk than percentages

– Narrative accounts convey the most risk

• Confirmatory bias: we interpret information in a manner that is consistent with our world view

• Hindsight bias

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How We Make Decisions: Biases

• Negative information, e.g. of a bad outcome, – Is rated as more valuable than positive

information– Those delivering negative news are seen as

more skilled

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How We Make Decisions About Risk

• These are all natural and, in most cases, adaptive elements of judgment and decision making, except– When biases unduly shape the outcome– When dealing with novel situations and the

usual mental “rules of thumb” lead us astray

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What Do We Know About Violence?

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• Increased arousal subtype (Impulsive)• Reactive, high affect, irritable, impulsive

• More co-morbidity with psychiatric diagnoses

• More responsive to clinical interventions

• May require containment to begin interventions

• Ex: Domestic violence, bar fight, road rage, most mental-illness associated violence

Subtypes of Violence

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Subtypes of Violence

• Proactive Subtype (Predatory), aka Targeted violence

• Planned

• Controlled, goal-directed, ego-syntonic

• May be affective “display”

• More socialization to violence

• Requires more external containment and sanction

• Ex: Domestic stalker, school or workplace violence

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Some Examples

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The Violence Formula

• Violence is the product of the interaction of:– Individual variables (personality traits, illness)

– Environmental variables (whether the environment promotes or dissuades violence)

– Situational variables (acute and chronic stress): FINAL• Financial

• Intoxication

• Narcissistic injury

• Acute or chronic illness

• Losses

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Mental Illness and Violence

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Traditional Views

• Public– Individuals with mental illness are at high risk of

violent behavior– Mental health professionals’ assessments of risk are no

better than chance

• Clinicians– The mentally ill are no more likely to be violent than

others– We’re able to assess risk with sufficient certainty to

justify civil commitment

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Current Research

• Mental disorder is a modest risk factor when the mentally ill are considered as a group

• There is a subgroup of individuals with serious mental illness who are at significantly increased risk

• Psychosis, substance abuse, and antisocial behavior are significant risk factors

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“Severe mental illness alone does not significantly predict future violence; rather,

historical, dispositional, and contextual factors are associated with future violence.”

Elbogen, E. B., Johnson, S. C. (2009). The intricate link between

violence and mental disorder. Archives of General Psychiatry, 66 (2),

152-161.

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Mental Illness and Violence

• Individuals most at risk– Individuals with substance abuse/dependence– Psychotic disorders with active symptoms

• Paranoia or control override

• History of Oppositional Defiant Disorder as children and/or

• History of Antisocial Personality Disorder as adults

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Violent Diagnoses by Group(From Steadman et al 1998)

Courtesy Judith G. Edersheim, MD, JD

Diagnosis: Percent Violent:Major Mental IllnessWithout Substance Abuse

17.9%

Major Mental IllnessWith Substance Abuse

31.1%

Other Mental Illness withSubstance Abuse

43.0%

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Substance Abuse as a Risk Factor

Self report of violence in previous year:DX %None 2OCD 11Bipolar/mania 11Panic disorder 12Major depression 12Schizophrenia 13Cannabis use/dependence 19Alcohol use/dependence 25Other use/dependence 35

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Limitations on the Utility of Studies of the Violent Mentally Ill

• Applicability to non-clinical populations– Not diagnosed– No diagnosis

• Applicability of static and dynamic risk factors– Are they the same for patients and nonpatients?– Cultural issues?

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The Risk Assessment Process

• Nature of the perceived threat/risk:• Targeted vs. impulsive• Relationship between actor and victim(s)• Manipulation vs.revenge

• Sources of information• Current circumstances• Risk factors• Records review (including criminal)• Interview—if possible• Applying the formula

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• Critical to distinguish between:– Historical (static) risk and protective factors

• Static risk factors cannot be changed

• Historical risk factors describe risk trajectory

• May provide actuarial risk against a base rate

– Dynamic risk and protective factors• Dynamic factors are points for intervention

• Social, family, community, clinical factors

Models of Assessing/Understanding Risk

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Assessing Risk of Violence

• Focus: Pose a threat vs. Make a threat- Some who make threats ultimately pose threats

- Many who make threats do not pose threats

- Some who pose threats never make them

- Hunters vs. Howlers

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Targeted Violence: Domestic and Otherwise

• Identifying information• Background information• Current life information• Attack-related behaviors• Motive?• Target selection• Communication with target or others?• Interest in targeted violence, perpetrators, extremists?

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Targeted Violence: Domestic and Otherwise

• History of mental illness?• Organized enough to act?• Recent loss or loss of status leading to

desperation and despair?• Actions consistent with statements?• Are those who know the subject concerned?• What factors in subject’s life might increase

or decrease risk?

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Pathway to Violence

6. Attack 5. Breach

4. Preparation 3. Research & Planning 2. Ideation 1. Grievance Calhoun and Weston, “Contemporary Threat Management” (2003)

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Specific Situations: Domestic Violence/Stalking

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Ontario Domestic Assault Risk Assessment

• Prior domestic assault (against a partner or child) in police .26

• Prior nondomestic assault (against anyone other than a partner or child) .15

• Prior sentence to a term of 30 days or more .28• Prior failure on conditional release (bail, parole,

probation, no-contact ord.) .25• Threatened to harm or kill anyone during index

offense .12• Unlawful confinement of victim during index

offense .12

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Ontario Domestic Assault Risk Assessment(cont’d)

• Victim fears repetition of violence .14• Victim and/or offender have more than one child

altogether .24• Offender is in stepfather role in this

relationship .22• Offender is violent outside the home (to people

other than a partner or child) .20• Offender has more than one indicator of substance

abuse problem .27• Offender has ever assaulted victim when she was

pregnant .13• Victim faces at least one barrier to support .11

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Risk Factors for Violence in Stalking

• Risk of physical violence in stalking 25-35%; risk of psychosocial harm much higher

• Prior intimate relationship• Threats (different from celebrity cases): 45% of those

threatened are assaulted• Mental illness: no evidence of clear relationship• Substance abuse, especially with other mental

disorder• Past criminal history(+/-), + if ex-intimate• Recidivism associated with: youth, prior intimate

relationship, Cluster B personality disorder, absence of psychotic or delusional disorder

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Assessing the Evidence

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The Jargon Problem

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Red Flags in Expert/Clinician Testimony

• Overstatement of certainty– “Full remission”– “Guarantee”– “Cured”

• Experiential vs. analytic thinking– Finger in the wind?– Is there data available on the issue? – Was it considered?

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Screening Instruments?

• PCL-R (Hare Psychopathy Checklist– Proven reliability and validity– High scores of failed conditional release and

recidivism– Possible Daubert problems re study population

• Projective tests, e.g. Rorschach Inkblot Test?

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Screening Instruments?• HRT-20

– Item categories: Historical, Clinical,Risk management– Max score is 40, but no cutoffs– Clinical and research tool

• VRAG (Violence Risk Appraisal Guide)– Offers prediction of recidivism by violent offenders– Accepted in some jurisdictions

• MacArthur Violence Risk Assessment Study– Diverse population of civilly committed patients– Identifies risk of violence within one year of discharge– A work in progress

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The Great Debate: Actuarial vs. Clinical

• Given the multiples influences on risk perception, will we put our trust in a pure analytic system?

• Current standard: risk assessment based upon actuarial risk factors informed by solid clinical judgment that is relatively free of affective heuristics and bias

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The Misinformation Challenge

“It ain’t so much the things we don’t know that get us into trouble. It’s the things we know that ain’t so.”Artemus Ward

(Charles Farrar Browne)