1. Consideration of Symptom Validity
as a Routine Component of
Forensic Assessment
Erin Eggleston PhD DipClinPsych
Reg. Clinical Psychologist

2. What I mean by Symptom
Validity….
The measurement or observation of
bias in test behaviour and self
reported psychopathology.
response bias
motivational inhibition / test underperformance
dissimulation / intentional feigning
self debasement
self enhancement / denial of everyday life
complaints/ presenting overly favourably
symptom exaggeration / magnification
symptom under reporting

3. What I mean by the forensic…
 Expert provision of clinical evidence
to inform decision making or court
proceedings.
 In New Zealand psychologists have
long been used as experts in the
Family Court.
 This type of assessment role is
growing as what we can do becomes
better understood.

4. Pitfalls when psychology interfaces
with law…
“If I talk with you, you’ll find out things about
me and then the Parole Board will find out
and keep me in longer” (offender, abridged)
“You Psychologists just say I’m high risk – that
doesn’t help me. So no I don’t consent”
(offender, abridged)

5. Making the Case….
 for knowing about and being able to
deliver basic Symptom Validity tests
as part of clinical screen in forensic
settings.
 For being willing to test the validity
and robustness of our psychological
findings
 Regarding the risks of not being
sure about symptom validity.

6. Incidence
 The known base rate internationally for
symptom exaggeration in neuropsychological
field ranges from 7.5% to 33% in clinical
settings.
 30-40% in settings where incentive exists…..e.g
compensation, classification and parole..but to
be fair we don’t know in NZ.
 Not sure of the numbers in the opposite
direction where incentive exists..e.g denial,
symptom minimisation.
Donders and Boonstra, 2007, Green, Rohling, Lees-Haley & Allen 2001; Binder and
Rohling, 1996; Lees-Haley, 1992; Trueblood & Schmidt, 1993:

7. What does the psych board say?
 The psychologist should be alert to motivational factors
which may bias the results in a particular direction. Do
we consider these factors?
 Where there is reason to question effort, symptom
validity assessment may be included… Hmm
 Be careful…they are worried about us talking about
Malingering… Do we?
 While psychologists often want to avoid having this
uncomfortable discussion, there is an obligation to
feedback the results of the assessment to the client.
Do we agree?
Draft Guidelines on Use of Psychometric Tests NZ
Psychologist Board (Dec 2011)

8. Psychometric review – tests examine:
 Psychiatric Symptoms (Rare, Improbable Absurd combinations, Severity,
Consistency, and Report Versus Observed).
 Self Deception
 Validity Scales on Personality Tests
 Memory symptoms
 IQ (VIP)
 Substance Abuse
 Somatic Perception
 Embedded measures across test batteries
Best practice suggests converging test data.

9. Four Case Studies

10. Case One: s38 Sexual Offender
 Psychiatrist says fit to plead and no
evidence of intellectual impairment
 Lawyer says clear ID.
Only a psychologist can sort this out

11. Testing
 Passed TOMM x2
 FSIQ in range of <60 (no difference across subtests)
 Very good at saying yes.
 BURT 6.5 year reading age
 Vineland II across two raters consistent with ID
 Special schooling, no employment, limited coping skills
It was the symptom validity test that
stood out strongly in court to show
this was a valid assessment of
functioning.

12. Case Two: ACC Data Assessment
(Risky/ SV testing recommended)
 PAI: strong negative bias
 DAPS: strong negative bias
 VIP / TOMM: valid.
 MSPQ: four times above cut-off for
back pain
 K10: severe
 CES-D: v.severe in range where
inpatient care should be considered.

13. Where we got to with some feedback…
 Some rapport was established by meeting
twice.
 Client agreed with strong negative bias
 Client agreed with paranoid ideation and
pervasive distrust, aggrieved, suspected that
others plotting against him. This was the
substantive barrier to change.
 Noted incentives
 Does meet criteria for PTSD but is difficult to
treat.
 Warrants specialist treatment (Psychiatry,
Clin.Psychology)

14. Case Three: s333 Youth court
 Youth considered by Social Worker
based on previous psychology
report to have ID and would likely
be placed in Youth ID Service
 Wanting to know what it would
mean if he scored lower vs. higher
 Knows that offending is serious and
persistent enough to lead to district
court sentencing.

15. Prior test results…
 WAIS IV (previous psych)
 Scores spanned from the extremely low range – scaled
score of 1 to the average range - scaled score of 10.
 Matrix reasoning- which is a robust indicator of overall
intelligence that is not impacted by schooling was in the
average range;
 Client admitted to engaging in previous tests with low
effort and that he was considering doing so with me
because he considered being found to be low
functioning would be useful in his court (incentive);

16. Case Four: [ACC] PTSD as a
consequence of physical injury
Referral: Assessment of the likely pre-injury mental health
condition and any mental condition (using DSM-IV) that is
subsequent to this and can be reliably linked to the covered
physical injury. This should include close examination of
the possibility of Post Traumatic Stress Disorder any other
cognitive, behavioural or emotional patterns that might
explain reported findings.

17. Symptom Validity findings…
The pattern detected across psychometric tests, clinical
interview data and corroborative sources indicated that while
Ms Jones did not actively or intentionally feign illness or
falsify symptoms, self-report was unreliable and likely to
include exaggerated symptoms. Ms Jones’s approach to
cognitive testing was reported as inconsistent; that is, there
was evidence of periods of optimum and sub-optimum effort.
Structured Inventory of Reported Symptoms
Millon Clinical Multiaxial Inventory –III
Validity Indicator Profile
Behavioural Evidence
Personal Motivators
Observed Testing Behaviour

18. Injury Focused Formulation
 (deleted)

19. Practice points
 Be a scientist practitioner and strengthen
psychological contribution to forensic environment by
openly testing alternative hypotheses and the validity
of our conclusions.
 Learn from the forensic field: Assess patterns
across test data, note clinical and behavioural
observations, consider incentives and use a range of
corroborative sources.
 Develop rapport and inform clients of the
components of the assessment
 Describe and formulate on response style.
Develop this component of your forensic report.
 Consider the utility of feedback and how best to
communicate your results both in terms of developing
your formulation and being fair to the client in terms of
hearing your findings first from you.