Comorbidities in People With Intellectual Disability With and Without Schizophrenia and Schizophrenia Without Intellectual Disability : A Swedish Register Study (IDcare)

Bakken, Trine Lise; Axmon, Anna; Sandberg, Magnus

Comorbidities in People With Intellectual Disability With and Without Schizophrenia and Schizophrenia Without Intellectual Disability : A Swedish Register Study (IDcare)

Mark

Bakken, Trine Lise ; Axmon, Anna ^LU

and Sandberg, Magnus ^LU

(2026) In Journal of Intellectual Disability Research 70(2). p.206-217

Abstract

BACKGROUND: Intellectual disability (ID) and schizophrenia are known to separately carry a high risk of comorbidity of mental health and physical conditions. However, the prevalence and risk of comorbidities among people diagnosed with concurrent ID and schizophrenia have to date not been studied.

METHODS: From a cohort including all people in Skåne, Sweden, the following three groups were established: (1) people with ID and concurrent schizophrenia, (2) people with ID without schizophrenia and (3) people with schizophrenia without ID. Diagnoses were determined using the Region Skåne healthcare database. Poisson regression was used to estimate relative risks (RRs) with 95% confidence intervals (CIs) of having at least one... (More)

BACKGROUND: Intellectual disability (ID) and schizophrenia are known to separately carry a high risk of comorbidity of mental health and physical conditions. However, the prevalence and risk of comorbidities among people diagnosed with concurrent ID and schizophrenia have to date not been studied.

METHODS: From a cohort including all people in Skåne, Sweden, the following three groups were established: (1) people with ID and concurrent schizophrenia, (2) people with ID without schizophrenia and (3) people with schizophrenia without ID. Diagnoses were determined using the Region Skåne healthcare database. Poisson regression was used to estimate relative risks (RRs) with 95% confidence intervals (CIs) of having at least one diagnosis in each ICD-10 chapter or block for group 1 versus groups 2 and 3, respectively. All analyses were adjusted for age at inclusion (i.e., 2014, continuous variable), sex and ethnicity.

RESULTS: For several diagnostic chapters, there were higher risks among people with ID and schizophrenia, compared to both those with ID without schizophrenia and those with schizophrenia but without ID. These chapters included the following: I (parasites), III (blood and immunity), IV (endocrine), VII (eye), XII (skin and tissue) and XIV (genitourinary). The blocks with the highest risks compared to the other two groups were diabetes mellitus, disorders of other endocrine glands, obesity and other hyperalimentation, organic-including symptomatic and mental health conditions, extrapyramidal and movement and other respiratory diseases principally affecting the interstitium.

CONCLUSIONS: People with the combination of ID and schizophrenia had an increased risk of both physical and mental health conditions that could not be explained by either ID or schizophrenia alone. A correct diagnosis for people with the combination of ID and schizophrenia is important for the provision of adequate treatment. Future research should investigate pathways and explanatory factors, as well as the provision of services for people with ID and schizophrenia.

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Please use this url to cite or link to this publication: https://lup.lub.lu.se/record/d080da9d-b955-448c-9f13-7c29ba2a5f05

author

Bakken, Trine Lise ; Axmon, Anna ^LU

and Sandberg, Magnus ^LU

organization

publishing date

2026-02

type

Contribution to journal

publication status

published

subject

Epidemiology

keywords

Humans, Sweden/epidemiology, Intellectual Disability/epidemiology, Schizophrenia/epidemiology, Male, Female, Comorbidity, Adult, Registries/statistics & numerical data, Middle Aged, Young Adult, Adolescent, Aged, Cohort Studies

in

Journal of Intellectual Disability Research

volume

70

issue

2

pages

206 - 217

publisher

Wiley-Blackwell

external identifiers

scopus:105023531341
pmid:41320546

ISSN

0964-2633

DOI

10.1111/jir.70067

project

Health care utilization in primary and specialist care among people with intellectual disability: A longitudinal register study

language

English

LU publication?

yes

additional info

id

d080da9d-b955-448c-9f13-7c29ba2a5f05

date added to LUP

2026-01-07 08:13:47

date last changed

2026-01-08 04:01:12

@article{d080da9d-b955-448c-9f13-7c29ba2a5f05,
  abstract     = {{<p>BACKGROUND: Intellectual disability (ID) and schizophrenia are known to separately carry a high risk of comorbidity of mental health and physical conditions. However, the prevalence and risk of comorbidities among people diagnosed with concurrent ID and schizophrenia have to date not been studied.</p><p>METHODS: From a cohort including all people in Skåne, Sweden, the following three groups were established: (1) people with ID and concurrent schizophrenia, (2) people with ID without schizophrenia and (3) people with schizophrenia without ID. Diagnoses were determined using the Region Skåne healthcare database. Poisson regression was used to estimate relative risks (RRs) with 95% confidence intervals (CIs) of having at least one diagnosis in each ICD-10 chapter or block for group 1 versus groups 2 and 3, respectively. All analyses were adjusted for age at inclusion (i.e., 2014, continuous variable), sex and ethnicity.</p><p>RESULTS: For several diagnostic chapters, there were higher risks among people with ID and schizophrenia, compared to both those with ID without schizophrenia and those with schizophrenia but without ID. These chapters included the following: I (parasites), III (blood and immunity), IV (endocrine), VII (eye), XII (skin and tissue) and XIV (genitourinary). The blocks with the highest risks compared to the other two groups were diabetes mellitus, disorders of other endocrine glands, obesity and other hyperalimentation, organic-including symptomatic and mental health conditions, extrapyramidal and movement and other respiratory diseases principally affecting the interstitium.</p><p>CONCLUSIONS: People with the combination of ID and schizophrenia had an increased risk of both physical and mental health conditions that could not be explained by either ID or schizophrenia alone. A correct diagnosis for people with the combination of ID and schizophrenia is important for the provision of adequate treatment. Future research should investigate pathways and explanatory factors, as well as the provision of services for people with ID and schizophrenia.</p>}},
  author       = {{Bakken, Trine Lise and Axmon, Anna and Sandberg, Magnus}},
  issn         = {{0964-2633}},
  keywords     = {{Humans; Sweden/epidemiology; Intellectual Disability/epidemiology; Schizophrenia/epidemiology; Male; Female; Comorbidity; Adult; Registries/statistics & numerical data; Middle Aged; Young Adult; Adolescent; Aged; Cohort Studies}},
  language     = {{eng}},
  number       = {{2}},
  pages        = {{206--217}},
  publisher    = {{Wiley-Blackwell}},
  series       = {{Journal of Intellectual Disability Research}},
  title        = {{Comorbidities in People With Intellectual Disability With and Without Schizophrenia and Schizophrenia Without Intellectual Disability : A Swedish Register Study (IDcare)}},
  url          = {{http://dx.doi.org/10.1111/jir.70067}},
  doi          = {{10.1111/jir.70067}},
  volume       = {{70}},
  year         = {{2026}},
}

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Comorbidities in People With Intellectual Disability With and Without Schizophrenia and Schizophrenia Without Intellectual Disability : A Swedish Register Study (IDcare)