Inventory of evidence gaps in mental health 2005–2020

Interventions to assess, diagnose, prevent and treat mental illness, including support measures and health and social care organisation

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SBU Policy support

identifies and presents available scientific evidence to support policy and decision making, including the development of national guidelines, at other government agencies. In consultation with professional experts, SBU staff generates supporting documentation to address the various questions that have been posed.

Published: Report no: 335 Registration no: SBU 2020/215 ISBN: 978-91-88437-84-6



In this report we present an inventory of previously identified evidence gaps in mental health from two databases: SBU's database of scientific evidence gaps and the British database The UK Database of Uncertainties about the Effects of Treatments (DUETs). Both databases indicate where either evidence summaries or primary research is needed for specific research questions. An evidence gap, or evidence uncertainty, entails that there is insufficient evidence of the effect of an intervention, regarding either a particular outcome or the overall effect. The lack of evidence may be either due to a lack of a systematic review of published primary studies, or that there exists a systematic review that shows that the effect of the intervention is uncertain.

This inventory may be used as a source of information for researchers and research funders, when determining which research questions that may be urgent to address and which evidence summaries may be important to conduct. It may also serve as a resource to inform health and social care service development, policy development, and research.


Evidence gaps labelled with Psychiatry and Psychology from SBU's database, and Mental Health from DUET's database were included. The inventory covered all types of mental illness and disorders, ranging from serious serious mental illness to milder mental health conditions and problems.

The interventions were targeted to individuals with mental illness, their families and next of kin, individuals at-risk for mental disorders, preventive interventions within mental health, staff working in the field of psychiatry or social services, as well as criminal offenders and individuals exposed to violence and crime. All types of interventions were included, from assessments, diagnosis, prevention, treatment, rehabilitation, support interventions, service organization and delivery of care. Evidence gaps in the two databases were sorted into the following population and intervention categories:

Population categories  Intervention categories
  • Neuropsychiatric conditions
  • Affective disorders
  • Schizophrenia & Psychotic disorders
  • Specific conditions
  • Substance Abuse & Addiction
  • Dementia & Elderly
  • Other mental health problems
  • Harms and negative effects

Adjacent populations:
  • Somatic disease
  • Pregnancy & Childbirth
  • Intellectual disability
  • Diagnostics & Assessments
  • Drug
  • Psychological & Psychotherapeutic
  • Medical device interventions & Surgery
  • Physiotherapy & Physical Activity
  • Diet & Nutrition
  • Lifestyle
  • Prevention
  • Prediction
  • Support & Patient information
  • Complementary medicine
  • Daily activities & Skills Training
  • Employment & Work Environment
  • Social care & Housing
  • Organization of care
  • Treatment options

The inventory is presented in three steps:

  1. Quantification: number of evidence gaps in different population and intervention categories
  2. Description: types of research questions in the intervention categories
  3. Listings: all evidence gaps in each intervention category (extracts from databases).


The inventory identified over 2000 evidence gaps with the field of mental health identified between 2005 and 2020. Most evidence gaps derive from systematic reviews and evidence summaries for national guidelines, notably from SBU, the Swedish National Board of Health and Welfare, Cochrane, the James Lind Alliance and NICE (National Institute for Health and Care Excellence).

The fields with most evidence gaps included psychological treatment in affective disorders, drug treatment for schizophrenia and depression, support interventions targeted to family members or within social work, and assessments regarding dementia. In some areas, no or very few evidence gaps were identified. These areas may reflect research questions that have not yet been investigated or evaluated, or alternatively that there is evidence of the effects of the interventions in that particular field. Some examples of areas with no identified evidence gaps included physical activity, support in bipolar and eating disorders, prediction of addiction, organization of care in self-harm, and negative effects of psychological treatment.


This report describes evidence gaps for interventions that have been evaluated by specific authorities and organisations in systematic reviews, clinical guidance or other sources. This inventory does not provide a comprehensive overview of all existing evidence gaps in the field of mental health, since no such international database with identified evidence gaps exists.

This inventory contains all evidence gaps identified between the years 2005-2020. This entails that also older evidence gaps are included. However, for several older evidence gaps, research needs still remain, as similar research questions were identified also in more recent evidence summaries.

Some examples of these were drug treatments and psychological interventions targeted to children with depression, or long-term effects of treatments or long-term harms. Thus, it cannot be assumed that older evidence gaps per definition are out of date. In certain research-intensive fields however, the evidence status has changed. In order to provide an up-to-date view of a specific research question, an updated systematic literature search is needed to identify new published research.

The aim of this inventory is to provide an overview of pre-existing identified evidence gaps. It does however not indicate which of the evidence gaps are the most important or urgent to address. In order to prioritize research questions, separate structured prioritization methods are available, for example the James Lind Alliance method.

The full report in Swedish

The full report in Swedish, Inventering av vetenskapliga kunskapsluckor inom psykisk ohälsa 2005–2020

Project group


  • Mussie Msghina, MD, PhD, specialist in psychiatry, associate professor, Örebro University Hospital


  • Malin Höistad, project manager, SBU
  • Lena Wallgren, project manager, SBU
  • Kerstin Mothander, project administrator, SBU
  • Marie Österberg, project support, SBU
  • Elizabeth Åhsberg, project coordinator, SBU
  • Sofia Tranæus, project supervisor, SBU

External reviewers

  • Simon Cervenka, prof psychiatry, Uppsala University
  • Bo Runeson, prof psychiatry, Karolinska Institutet
  • Urban Markström, prof social work, Umeå University
  • Marie Rahlén Altermark, social work development, Jönköpings county
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