Development of the self-Dehumanisation in Psychosis Scale (DiPS)

Tom Jenkins

Dr. Pamela Jacobsen, Dr. Bethany O'Brien-Venus & Prof. Paul Chadwick

Overview

• Measure development 101
• Introduction to dehumanisation
• Development of the DiPS
• Validation of the DiPS
• Questions & discussion

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Terminology

Measure development 101

• Historically, psychological outcome measures have not been rigorously developed (ie. Measurement crisis)

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• Best practice guidance now exists for health related outcome measures (Terwee, 2007; COSMIN; Boateng et al. 2018; Carlton et al., 2020)

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‘Questionable measurement practice’ (Flake & Fried, 2020)

• Lack of transparency around choice of or development of measure
• Lack of clarity around construct being measured
• Lack of reported/poor/no statistical properties of measure
• Modifications of existing measures
• Lack of target population involvement within measure development (Terwee et al., 2008) – PPI/E v research participants

Good measurement practise

• Identification of domain and item generation
• Content validity
• Pre-testing of questions
• Sampling and survey administration
• Item reduction
• Extraction of factors
• Tests of dimensionality
• Tests of reliability
• Tests of validity

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Boateng et al. (2018)

Challenges with good measurement practise

Time

Money

Dehumanisation

The conception of another person as less, or other than human

“These aren’t people, these are animals”

Donald Trump

Kteily et al., 2015

Self-dehumanisation

Feeling less, or other than human

• People with psychosis are perceived and treated as less human than other people (Boysen et al., 2020)
• People with psychosis report feeling dehumanised (O’Brien-Venus et al., 2023)

Measure development

Qualitative interviews

Literature review

PPI consultations

Delphi study

Cognitive interviews

Psychometric evaluation

Qualititive interviews

Participants: N=20 people with experience of distressing voices

Analysis: Reflexive Thematic Analysis

Results:

Self-dehumanisation as the end of experiential continua

Extent of distressing sensory fragmentation

Sense of belonging with other humans

Integrity of self as a private, coherent entity

Sense of worth as a human being

Strength of personal agency

Trust in own credibility and reliability

O’Brien-Venus, Jenkins & Chadwick, 2023

Item generation

PPI consultation

2x focus groups

Qualitative interview transcripts

Literature search and review

N=59 items

Delphi study: content validity

Stakeholders:

N = 17 people with experience of distressing psychosis

N = 15 mental health professionals

N = 11 dehumanisation researchers

N = 6 carers of people with psychosis

Round 1:

59 items rated

34 excluded, 20 re-rated, 5 amended

7 suggested and taken to R2

Round 2:

33 items rated

25 included, 8 excluded

N=25 items

Delphi:

Consensus method with expert stakeholders to agree on most important statements to reflect an outcome (dehumanisation)

Cognitive interviews: item pre-testing

Round 1:

25 items

2 removed, 6 amended, 1 added

Round 2:

24 items

3 amended

Round 3:

24 items

2 removed

N=22 items

• ‘Think aloud’ method
• N=9 people with experience of distressing psychosis
• Three rounds, N=3 in each

Cognitive interviews: item pre-testing

I feel dehumanised by my experience of psychosis

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I am more than my psychosis

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I can’t trust my thoughts and feelings

I feel a sense of belonging with other people

I do not belong with other people

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“Before this study I wouldn’t know what dehumanised means”

“I don’t like ‘my’ psychosis – I don’t feel like I own it”

“I don’t know who you mean by other people – some people accept me, but others don’t”

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“I don’t have feelings, but I have thoughts – these are two different things”

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• I am more than my experience of psychosis

• I feel a sense of belonging with the people in my life

• I do not belong in this society

• I can’t trust my own feelings

DiPS validation

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• Currently underway!

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• N=220 people with recent experience of psychosis

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• Reliability, validity, factor analysis

DiPS Validation: procedure

T1

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DiPS

Self-compassion

Self-stigma

Voices

Paranoia

T2 (3-7 days later)

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DiPS

DiPS validation

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• Item reduction
• Internal consistency (Cronbach’s alpha)
• Test-retest reliability (T1, T2)
• Construct validity (correlations)
• Exploratory factor analysis
• (Confirmatory factor analysis)

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Belonging

Personal agency

Psychosis

Self-worth

Trust in oneself

Dehumanisation

Self-dehumanisation

Private and coherent self

"I do not belong in this society”

"Psychosis makes me feel disconnected from the world"

“I have no private thoughts and feelings”

"I am worth less than other people"

"I can't trust my own mind"

"I do not have control over my actions"

"I see myself as less than human"

Clinial implications & future directions

Therapy

Research

Society

Thank you!

Questions/discussion?

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Email: tj260@bath.ac.uk

Twitter: @tajenkins_