How should we evaluate research on counselling and the treatment of depression? A case study on how NICE’s draft 2018 guideline considered what counts as best evidence

Background: Health guidelines are developed to improve patient care by ensuring the most recent and “best available evidence” is used to guide treatment recommendations (NICE Guidance, 2017). NICE’s revised guideline development methodology acknowledges that evidence needed to answer one question (treatment efficacy) may be different from evidence needed to answer another (cost effectiveness, treatment acceptability to patients; NICE, 2014/2017). This review uses counselling in the treatment of depression as a case study, and interrogates the constructs of ‘best’ evidence and ‘best’ guideline methodologies. Method: The review comprises six sections: (1) the implications of diverse definitions of counselling in research; (2) research findings from meta-analyses and randomised controlled trials (RCTs); (3) limitations to trials-based evidence; (4) findings from large routine outcome datasets; (5) the inclusion of qualitative research that emphasises service-user voices; and (6) conclusions and recommendations. Results: Research from meta-analyses and RCTs reviewed in the draft 2018 NICE guideline is limited but positive in relation to the effectiveness of counselling in the treatment for depression. The weight of evidence suggests little, if any, advantage to CBT over counselling once bias and researcher allegiance are taken into account. A growing body of evidence from large NHS datasets also evidences that counselling is both effective and cost-effective when delivered in NHS settings. Conclusion: Recommendations in NICE’s own updated procedures suggest that sole reliance on RCTs and meta-analyses as best methodologies is no longer adequate. There is a need to include large standardised collected datasets from routine practice as well as the voice of patients via high-quality qualitative research.