Why treatment manuals of psychological interventions should be freely available
Authors: Pim Cuijpers, Niall Boyce, Mark van Ommeren
Journal: The Lancet Psychiatry (2024)

More than 80% of the almost 1 billion people with mental disorders live in low-income and middle-income countries.1WHOWorld mental health report: transforming mental health for all. World Health Organization, Geneva2022Google Scholar The majority of these individuals have very little or no access to evidence-based treatments, and major efforts are underway to build up mental health services in these regions.1WHOWorld mental health report: transforming mental health for all. World Health Organization, Geneva2022Google Scholar However, delivery of high-quality, rigorously assessed, and effective treatments requires that the necessary materials be available, freely or at an affordable price; as, for example, is the case for drugs on the Essential Medicines List.2WHOThe selection and use of essential medicines 2023: executive summary of the report of the 24th WHO Expert Committee on the Selection and Use of Essential Medicines, 24–28 April, 2023. World Health Organization, Geneva2023Google Scholar Unfortunately, many manuals describing psychological interventions are not freely available. We found that among 19 trials of psychological interventions that reported that they had used a manual,3Watts S van Ommeren M Cuijpers P Open access of psychological intervention manuals.World Psychiatry. 2020; 19: 251-252Crossref PubMed Scopus (13) Google Scholar only eight correctly reported a manual in the bibliography and six of these eight references were to generic manuals that were adapted for use in the specific context or population. This raises substantial questions regarding the replicability of studies and suggests that insufficient information is provided in the literature for evaluation and for clinical use of the examined interventions. The free, preferably open access availability of manuals of psychological interventions is also key to research on psychological treatments. A manual outlines the psychological techniques used and elements such as the duration of sessions and specific details of the content of interventions. In most research papers of randomised clinical trials of psychological interventions, only very brief descriptions of the psychological interventions are given. These descriptions are typically insufficient to implement the intervention, accurately understand the intervention, interpret the results across studies in meta-analyses to identify the active ingredients and mechanisms, and to replicate the study. Not knowing precisely what was done places severe limitations on our ability both to evaluate individual reports and to synthesise evidence. Making manuals freely available and open access is not without its problems. One issue is that when manuals can be easily accessed, it cannot be guaranteed that clinicians who deliver the intervention (eg, psychotherapists, doctors, other health-care workers, or lay health counsellors) are qualified or are sufficiently trained to do so. That could lead to smaller overall effects, negative outcomes, and even adverse events. People who might have been helped by high-quality delivery of the intervention could be demotivated by substandard delivery. Good manuals should provide information about the needed qualifications and level of experience for clinicians to deliver the intervention, the training that clinicians need to have before they can deliver the intervention, and other quality criteria that are needed, such as certification and supervision when delivering the intervention. Many psychological interventions are owned by the developers who copyright the manuals and materials and might not want to lose revenue or other opportunities by making these freely available online. However, manuals and development work are frequently paid for with public funds. A good model is Problem Management Plus.4WHOProblem Management Plus (Group PM+): individual psychological help for adults impaired by distress in communities exposed to adversity (generic field-trial version 1.0). World Health Organization, Geneva2016Google Scholar This brief intervention was developed and tested by WHO. It was made freely available online in 2016, immediately after completion of two randomised trials and has since been downloaded more than 350 000 times. Free access to the manual has led to numerous independent replication trials across the world.5Schäfer SK Thomas LM Lindner S Lieb K World Health Organization's low-intensity psychosocial interventions: a systematic review and meta-analysis of the effects of Problem Management Plus and Step-by-Step.World Psychiatry. 2023; 22: 449-462Crossref PubMed Scopus (12) Google Scholar The problem of free access to treatment manuals cannot be solved by a single stakeholder. It requires coordinated action from all those involved. Developers and authors need to be convinced that free access of their materials will help with the broad dissemination of their work and will improve the lives of people. People with lived experience might be powerful advocates for free access because this is likely to accelerate the dissemination of evidence-based interventions and reduce power differences in access to information on their care. Editors of clinical journals should require that authors at least state whether the intervention manual is freely available online and, if so, where to access it or note the legal or ethical reasons for denying free access. Peer reviewers of randomised control trials should have access to the manuals used so they can fully understand what is being tested. Funders can influence developers and researchers to make intervention manuals freely available online, for example, by mandating this as part of funding agreements. Online, free availability of manuals is also key to the dissemination of evidence-based psychological interventions, especially in the more than 800 million people with mental health problems in low-income and middle-income countries. Currently, too few manuals are freely available, and a coordinated action of researchers, people with lived experience, journal editors, and funders is crucial to solve this problem and to make sure that everything is done to make effective care available for those who need it. We declare no competing interests. The authors alone are responsible for the views expressed in this Correspondence and they do not necessarily represent the views, decisions, or policies of the institutions with which they are affiliated.