DOI: 10.15125/bath-01494
title: Dataset for validation of the self-Dehumanisation in Psychosis Scale (DiPS): measuring feelings of self-dehumanisation in people who experience psychosis

description: The dataset contains data collected from 456 people with experience of psychosis who participated in a study to validate the self-Dehumanisation in Psychosis Scale (DiPS). Demographic information includes ethnicity, gender, age, diagnosis, and whether a person is taking anti-psychotic medication. There are data from five self-report questionnaires collected at one time point: self-Dehumanisation in Psychosis Scale (DiPS); Self Compassion Scale Short Form (SCS-SF) (Raes et al., 2013), Revised Green et al., Paranoid Thoughts Scale (R-GPTS) (Freeman et al., 2021); Hamilton Programme for Schizophrenia Voices Questionnaires (HPSVQ), (Van Lieshout & Goldberg, 2007); Internalized Stigma of Mental Illness Inventory-9 (ISMI-9) (Hammer & Toland, 2017). 
The DiPS was completed at a second time point 3-7 days after the first to assess test-retest reliability. A subset of 197 participants completed the DiPS at the second time point.
description: There were two arms of recruitment for this study: NHS and non-NHS.

- NHS participants were recruited from 16 NHS sites across England and Wales with support from the NIHR Clinical Research Network. Participants from NHS services with a diagnosis of schizophrenia spectrum disorder or eligibility for Early Intervention in Psychosis services were approached by local research teams and offered study participation. 
- Non-NHS participants were recruited through advertisements with mental health charities. Participants were required to have recent experience of distressing psychosis to be eligible for the study. 
- Both NHS and non-NHS participants were required to be 18 years old or above, and understand English language well enough to comprehend study materials.

Once participants agreed to take part, they completed the questionnaires either via REDCAP or paper copy. Paper copy results were then entered manually into REDCAP. Participants completed 'Survey 1', involving DiPS, SCS-SF, ISMI-9, R-GPTS, and HPSVQ at time point 1. A subset of participants then completed 'Survey 2' (DiPS for a second time) at time point 2.
description: 1) Participant entries in which Survey 1 has not been completed have been removed.
2) Mean imputation was used to replace missing data from questionnaires in which <20% items were incomplete.
3) Participants who indicated 'Other' for mental health diagnosis were asked to specify their using a free text entry box. This specification has been removed to avoid exposing potentially identifiable information.
4) One participant indicated a diagnosis of schizotypal disorder ('3' for diagnosis). This has been grouped with 'Other' to avoid exposing potentially identifiable information.
description: Dataset was collected using REDCAP or on paper (then subsequently entered into REDCAP).
description: Important: This dataset displays data scores for the 22-item DiPS. Following analysis in the DiPS validation study, the number of items in the DiPS was reduced to 13. 

For researchers seeking to conduct secondary analysis on this dataset, it is imperative that the 13-item DiPS is analysed, not all 22 items. 

To do this, please select the following 13 items: dips2, dips4, dips6, dips7, dips8, dips9, dips10, dips12, dips13, dips14, dips17, dips21, dips22.