An Inventory of Problems–29 (IOP–29) study investigating feigned schizophrenia and random responding in a British community sample

TL;DR: The IOP–29’s feigning scale (FDS) showed excellent validity in discriminating honest responding from feigned schizophrenia (AUC = .99), and its classification accuracy was not significantly affected by the presence of schizotypal traits.

Abstract: Compared to other Western countries, malingering research is still relatively scarce in the United Kingdom, partly because only a few brief and easy-to-use symptom validity tests (SVTs) have been v...

Summary

Introduction

• Food and health are the two integral components of human wellbeing.
• Supersaturation of urine in presence of calcium and oxalate facilitates calcium oxalate stone development (Paliouras et al., 2012).

Phytochemical analysis

• All the qualitative phytochemical profiling was performed according to the AOAC method (Shameh et al., 2018) and is represented in supplementary table 1.
• Estimation of total phenol content (TPC) CC-BY 4.0 International licensemade available under a (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.
• It is The copyright holder for this preprintthis version posted June 1, 2021.
• The free radical scavenging activity of all the plant extracts was measured by the DPPH (1,1-diphenyl-2picrylhydrazyl) method (Meghashri et al., 2010).
• Varied concentrations of the extracts [5 µg/mL, 10 µg/mL, 15 µg/mL, 20 µg/mL, and 25 µg/mL of gallic acid equivalent] followed by 1 mL of DPPH solution, shaken and was incubated at room temperature for 20 min in the dark after which absorbance was measured at 517nm.

Metal ion chelating assay

• Different concentrations of all extracts were taken, 50 µL of FeCl2 and 200 µL of ferrozine were mixed and incubated at room temperature in the dark for 10 min; finally, absorbance at 562 nm against blank was measured.
• The same equation used in DPPH scavenging activity is used here to know the capacity of the extract in cheating ferrous ions with EDTA considered as standard.

Reducing power assay

• Reduction of iron (III) by the extracts was measured with slight modification (Nedamani et al., 2015) by adding the various concentration of all extracts and made up the volume to 500 µL with phosphate buffer (20 mM) and then 500 µL of sodium ferricyanide (1%) was added and incubated at 50°C for 20 min.
• 500 µL of trichloroacetic acid (10%) was added to the solution to terminate the reaction followed by 10 min centrifugation.
• CC-BY 4.0 International licensemade available under a (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.
• It is The copyright holder for this preprintthis version posted June 1, 2021.

Anti-lithiatic activity

• The anti-lithiatic activity was assessed for all the extracts according to Phatak and Hendre, (2015).
• Then these eggs were washed carefully with distilled water and were immersed in a beaker containing 2N HCL overnight for decalcification.

Nucleation assay

• The nucleation of calcium oxalate crystals was estimated using a spectrophotometer, and Kalanchoe pinnata inhibiting potency was determined by the method of Saha and Verma (2013), with minor alteration.
• Calcium chloride 4 mmol/L and sodium oxalate 50 mmol/L were mixed to initiate crystallization, and this was added to artificial urine.
• Nucleation rate was obtained by equating the time of crystal formation about the presence of varying concentrations of Kalanchoe pinnata and with no extract in another and also Cystone was used as the positive control, absorbance was recorded at 1 hour, 3 hours, and 24 hours at 620 nm, percentage inhibition was calculated accordingly.
• CC-BY 4.0 International licensemade available under a (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.
• It is The copyright holder for this preprintthis version posted June 1, 2021.

Aggregation assay

• Saha and Verma (2013) method was tailored slightly to obtain the rate of aggregation of crystals of calcium oxalate.
• Calcium chloride and sodium oxalate 50 mmol/L solutions were mixed to obtain COM crystals.
• The two solutions were equalized by incubating in a water bath at 60°C for 1 hour and then brought to 37°C followed by evaporation.
• The blood which was heparinized was centrifuged for 15 min at 1000g through which the buffy coat and plasma were separated, and the erythrocytes with the help of PBS were rinsed thrice at room temperature reintroduced into PBS for further analysis, and the volume was made up four times.
• For 5 min, Kalanchoe pinnata was incubated with erythrocytes and then further incubated for 1 hour at 37°C with hydrogen peroxide, ferric chloride, and ascorbic acid and kept in a shaker incubator for incubation and was observed under an optical microscope for any changes in the morphology (Beulah et al., 2015).

High-Performance Liquid Chromatography (HPLC) Profiling

• The crude aqueous fraction, a hot extract of Kalanchoe pinnata was subjected to HPLC in a C-18 column with different mobile phase water: acetonitrile in the ratio 80:20 (Meghashri et al., 2010).
• The following standards were used to measure Ferulic acid .
• CC-BY 4.0 International licensemade available under a (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.
• It is The copyright holder for this preprintthis version posted June 1, 2021.

Statistical analysis

• All data were expressed as mean ± standard deviation (n = 3).
• Results were determined using one-way analysis of variance , followed by Duncan’s multiple range test using GraphPad Software, Inc (version 6.0, California, USA).
• The results were considered statistically significant if the P < 0.05.
• The minimum dosage of extract that is necessary to produce 50% inhibition was known as the effective dose (ED50), which is calculated using regression analysis.

Results & Discussion

• Phytofractions are extensively used as nutraceuticals in complementary and alternative medicine to boost health and to prevent stress, inflammation, and secondary lifestyle diseases.
• CC-BY 4.0 International licensemade available under a (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.
• Henceforth for all further studies, these five aqueous phytoextracts were considered.
• The K.pinnata phyto-cocktail exhibited potential hampering of the induced oxidant partially at 5µg/mL and completely at 25µg/mL in comparison to gallic acid (pure drug) and cystone as standard drug.

Acknowledgments:

• The authors thank, Dr. Trevani, Herbarium Section, Department of Studies in Botany, University of Mysore, for identification of the screened botanicals.
• Special thanks to Prof. Sunil S. More, Dean, School of Basic and Applied Sciences, DSU for all approval and permissions during the execution of this research work.
• CC-BY 4.0 International licensemade available under a (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.
• It is The copyright holder for this preprintthis version posted June 1, 2021.

Figures

Figure 2 contains the non-significant interaction effect between condition and Introvertive

Full text

A BRITISH VALIDATION OF THE IOP-29
1
Abstract
Compared to other Western countries, malingering research is still relatively scarce in the United
Kingdom, partly because only a few brief and easy-to-use symptom validity tests (SVTs) have
been validated for use with British test-takers. This online study examined the validity of the
recently introduced Inventory of Problems – 29 (IOP-29; Viglione, Giromini, & Landis, 2017) in
the detection of feigned schizophrenia and random responding in 151 British volunteers. Each
participant took three IOP-29 test administrations: (a) responding honestly; (b) pretending to
suffer from schizophrenia; and (c) responding at random. Additionally, they also took the O-
LIFE questionnaire of schizotypy under standard instructions (i.e., responding honestly). The
chief feigning scale of the IOP-29 (FDS) showed excellent validity in discriminating honest
responding from feigned schizophrenia (AUC = .99), and its classification accuracy was not
significantly affected by the presence of schizotypal traits. Additionally, a recently introduced
IOP-29 scale aimed at detecting random responding (RRS) also demonstrated very promising
results.
Keywords: British; Feigning; Inventory of Problems; IOP-29; Malingering; O-LIFE; Online;
Random Responding; Schizophrenia; Schizotypy; Validity.

A BRITISH VALIDATION OF THE IOP-29
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An Inventory of Problems – 29 (IOP–29) Study Investigating Feigned Schizophrenia and
Random Responding in a British Community Sample
Malingering is an intentional feigning or exaggeration of symptoms in order to gain
external incentive (American Psychiatric Association, 2013). Feigning illness or disability is
costly to society as resources are displaced away from people who are genuinely ill. Malingering
should therefore be considered a possibility every time an individual may gain from presenting
as impaired (Binder, 1993).
To evaluate the possible presence of malingering, forensic assessors typically rely on
multiple sources of information (Boone, 2013). In addition to clinical interviews and collateral
information, psychological tests are a rich source of information which assessors can rely on in
order to derive judgment. These tests are often grouped into two major categories: symptom
(SVT) and performance (PVT) validity tests. The former refers to tests aimed at evaluating the
credibility of self-reported psychological difficulties or problems, the latter refers to tests aimed
at evaluating the credibility of scores on cognitive tests. SVTs and PVTs, however, can only
inform on the level of validity/credibility of a given presentation; they cannot tell whether an
invalid/non-credible clinical presentation is feigned for an external versus internal motivation
(van Impelen, Merckelbach, Jelicic, & Merten, 2014). As such, neither SVTs nor PVTs, per se,
measure malingering. In line with Rogers and Bender (2013), in this article we thus refer to
malingering to indicate the “deliberate fabrication or gross exaggeration of psychological or
physical symptoms for the fulfilment of an external goal,” and feigning to indicate the “deliberate
fabrication or gross exaggeration of psychological or physical symptoms (Rogers & Vitacco,
2002) without any assumptions about its goals” (p. 518).

A BRITISH VALIDATION OF THE IOP-29
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Most SVT research and resulting base rates of non-credible symptom have come from the
United States (Martin, Schroeder, & Odland, 2015; Young, 2014, 2015). Comprehensive meta-
analyses of various forensic assessment studies point to base rates of 15±15% for malingering
(see Young 2015), although non-credible presentations seem to occur at higher base rates,
possibly around 40% (Larrabee, 2003), in neuropsychological assessment (see Young, 2014),
and at an even higher than 50% base rate in medico-legal disability claimants and forensic
criminal cases, especially if validated screens such as the Miller Forensic Assessment of
Symptoms Test (M-FAST; Miller, 2001) are used (Rogers & Bender, 2018). Less is known
concerning base rates of malingering and non-credible symptom reporting in the UK, as there is
not widespread use of the psychological tests (McCarter, Walton, Brooks, & Powell, 2009), and
this is in large part due to the division of medical and legal systems of care (Halligan, Bass, &
Oakley, 2003). More specifically, the UK substantially lacks symptom validity assessment
research (Merten et al., 2013), which notably limits the possibility to investigate malingering-
related phenomena within this cultural context.
Symptom Validity Assessment in the UK
While SVTs are very commonly used in the US, a less stringent approach is taken in the
UK, in large part due to British Psychological Society (BPS) caution against using these
instruments (McMillan et al., 2009), especially when there is initially no forensic context for
treatment. As the UK approaches mental healthcare treatment and forensic rehabilitation in
highly centralized systems, use of SVTs in clinical clients within a medico-legal context (e.g.,
claimants) is a grey area fraught with potential systemic complications.
In a review of symptom validity practices in European countries, Merten and colleagues
(2013) note a paucity of SVT research in Great Britain, specifically a lack of litigant studies, a

A BRITISH VALIDATION OF THE IOP-29
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lack of studies evaluating chronic pain, and a lack of studies in the context of criminal forensic
neuropsychological assessments. This is reflected in UK clinical practice as "few psychologists
[provide] these specialist assessments" (p. 135). In a review of both academic and government
statistics, there is a scarcity of information concerning base rates of cognitive impairment
(McMillan et al., 2009), suspected rates of feigning of specific disorders, and fraudulent medico-
legal claims in the UK. One of the biggest issues concerning SVT research in the UK is a general
lack of reported base rates for non-credible responding, however there is no data suggesting UK
rates would be dramatically different from those reported in the US, and there is certainly not
reason to believe rates of non-credible responding would be lower in the UK. For medico-legal
disability claimants and forensic criminal cases, the BPS points to the US as a guide for base
rates of malingering (McMillan et al., 2009), at approximately 54 to 72% (see Miller, Ryan,
Carruthers, & Cluff, 2004; Chafetz, 2008), and approximately 54% respectively (see Ardolf,
Denney, & Houston, 2007).
In a self-selected survey of 91 British neuropsychologists practicing in medico-legal
clinical cases (McCarter et al., 2009), only 7% reported they viewed SVTs as mandatory, and
only 13% of them reported using SVTs most of the time (>95%). Top reported reasons for not
using SVTs included: invalidity is obvious in presentation (38%), invalidity is obvious in (other)
test scores (38%), insufficient time (35%), and the belief that few patients exaggerate (34%). An
outdated reliance on clinical intuition and the belief that most clients were genuine was largely
regarded as the reason that most of these experts did not use SVTs, and the authors
acknowledged that this finding, in conjunction with varying approaches, frequency of use, and
measures, was likely to significantly bias attempts to report base rates of malingering. Currently,
practitioner and community-based whistleblowing via the NHS Counter Fraud Authority serves

A BRITISH VALIDATION OF THE IOP-29
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as the main system for combating patient abuse of services (Department of Health & Social Care,
2020).
Despite the paucity of information concerning base rates of non-credible responding,
fraudulent medico-legal claims are becoming an increasing issue in the UK (McCarter et al.,
2009). The UK Department for Work and Pensions (2019) reported overpaying £4.1 billion in
welfare benefits in 2018-2019, as fraudulent overpayments have jointly been awarded at the
highest estimated level (1.2%) steadily since 2016-2017. The UK Disability Unit (2020) offers
several financial benefits for individuals affected by long term (i.e., if it is likely to last 12
months) mental health problems, and schizophrenia is listed one of these stated conditions. To
promote research in this area, it would be beneficial to validate brief and easy-to-use SVT like
the Inventory of Problems – 29 (IOP-29; Viglione & Giromini, 2020; Viglione, Giromini, &
Landis, 2017) for use with a British population.
Schizophrenia and Schizotypy
Schizophrenia and its associated symptoms are among the more commonly feigned
psychiatric complaints in criminal forensic contexts (see Pierre, Shnayder, Wirshing, &
Wirshing, 2004). According to the World Health Organization classification (WHO, 2008)
schizophrenia is one of the most severe disabilities. The DSM-5 considers schizophrenia as a
spectrum disorder, which includes delusions, hallucinations, and/or disorganized speech, and can
also include grossly disorganized behavior, catatonic behavior, or negative symptoms. Similarly,
the ICD-11 contains a section on Schizophrenia and other primary psychotic disorders, which are
characterized by significant impairments in reality testing and alterations in behavior. These
symptoms manifest as positive symptoms (i.e., changes in behavior or thoughts), such as
persistent delusions, persistent hallucinations, disorganized thinking (typically manifest as

Frequently asked questions

Q1. What is the common form of resistance to a SVT?

Partial resistance might emerge in the form of discontinuing effort and cooperation after initially attempting to answer questions honestly. 

Q2. What did the authors do to encourage participants to fake schizophrenia?

To incentivize participants to fake schizophrenia well, it was emphasized that the best three fakers who can "trick the psychologist into thinking [they] have schizophrenia," would win one of three £20 (~$30 USD) cash prizes. 

Q3. What was the effect of the RRS on the FDS?

in the HON condition, where the FDS was supposed to be low, the presence of some randomness in the responses tended to artificially inflate the FDS values. 

Q4. What did the authors do to determine whether schizotypal traits could influence the IOP-?

The authors hypothesized that: 1) SIM condition would yield significantly greater FDS scoresthan HON, with large effect sizes; 2) individuals with higher schizotypal traits would score higher on FDS in condition HON in comparison to individuals with low schizotypal traits (as they are expected to show higher inconsistency in their responses) and perhaps lower on FDS in condition SIM (due to the overlapping symptomatology with schizophrenia itself); 3) RND condition would yield significantly higher RRS scores than both HON and SIM conditions, with no significant differences in RRS scores between HON and SIM. 

Q5. What should be the main focus of future studies?

Future studies should identify and investigate specific styles of random responding (e.g., reading difficulties, distractibility, and resistance) as they relate to honest and feigned responding. 

Q6. What did the authors encourage participants to do before participating in the study?

Participants were informed of the nature of the study before participating, and that they would be asked to take the same questionnaire three times - once, responding honestly, once responding randomly, and once responding as if they had schizophrenia. 

Q7. What did you think of the psychologist when you shared your family history?

You remember very clearly that when you shared your family history, the psychologist mentioned that you may be at risk of developing a psychotic disorder. 

Q8. What is the pharmacogenetics of a functional polymorphism?

Human catechol-O-methyltransferase pharmacogenetics: Description of a functional polymorphism and its potential application to neuropsychiatric disorders. 

Q9. What are the two types of responses?

Random responding and malingering are both considered to be invalid response styles, and both response styles may at times produce overstated pathology and suboptimal performance on cognitive items and/or neuropsychological tests (Rogers, 2008). 

Q10. What were the three different ways participants were asked to respond to the questionnaire?

Participants were then instructed to take the same questionnaire three times, in three different ways - responding honestly, responding randomly, and responding as if they are faking schizophrenia. 

Q11. What did the researchers do to test the effect of schizotypal traits on the I?

all participants also took a brief measure of schizotypal traits under standard instructions, i.e., with the request to respond honestly. 

Q12. How did the authors calculate Cohen’s effect size?

With regard to Cohen’s d effect size, in line with Dunlap, Cortina, Vaslow, and Burke’s (1996) recommendations, the authors calculated it using standard independent samples d formula (1988) rather than Morris and DeShon’s (2002) corrected value, as the authors were interested in calculating the actual effect size as opposed to an a priori power calculation.