Factorial Designs Help to Understand How Psychological Therapy Works

Abstract

A large amount of research time and resources are spent trying to develop or improve psychological therapies. However, treatment development is challenging and timeconsuming, and the typical research process followed-a series of standard randomized controlled trials-is inefficient and sub-optimal for answering many important clinical research questions. In other areas of health research, recognition of these challenges has led to the development of sophisticated designs tailored to increase research efficiency and answer more targeted research questions about treatment mechanisms or optimal delivery. However, these innovations have largely not permeated into psychological treatment development research. There is a recognition of the need to understand how treatments work and what their active ingredients might be, and a call for the use of innovative trial designs to support such discovery. One approach to unpack the active ingredients and mechanisms of therapy is the factorial design as exemplified in the Multiphase Optimization Strategy (MOST) approach. The MOST design allows identification of the active components of a complex multicomponent intervention (such as CBT) using a sophisticated factorial design, allowing the development of more efficient interventions and elucidating their mechanisms of action. The rationale, design, and potential advantages of this approach will be illustrated with reference to the IMPROVE-2 study, which conducts a fractional factorial design to investigate which elements (e.g., thought challenging, activity scheduling, compassion, relaxation, concreteness, functional analysis) within therapist-supported internet-delivered CBT are most effective at reducing symptoms of depression in 767 adults with major depression. By using this innovative approach, we can first begin to work out what components within the overall treatment package are most efficacious on average allowing us to build an overall more streamlined and potent therapy. This approach also has potential to distinguish the role of specific versus non-specific common treatment components within treatment.

Effectiveness of a Multicomponent Treatment based on Pain Neuroscience Education, Therapeutic Exercise, Cognitive Behavioural Therapy, and Mindfulness in Patients with Fibromyalgia (FIBROWALK study): A Randomized Controlled Trial.

“…In short, using our multicomponent treatment as example, patients would be As stated above, this is the first study to demonstrate the effectiveness of a multicomponent treatment that specifically integrates PNE in patients with FM. There are many studies that support the individual effectiveness of each of the treatment components that constitute this multicomponent therapy 11,[13][14][15][18][19][20][21][22][23][24][25][26][27][63][64][65][66][67][68][69][70][71][72] . In spite of the complexity of integrating different ingredients, the present RCT was designed on the basis of a clear and replicable methodology.…”

On the Road to Personalized Psychotherapy: A Research Agenda Based on Cognitive Behavior Therapy for Depression

“…The factorial design also provides a strong test of the relative contribution of specific vs. common factors, which is another advantage. The design proposed by Watkins et al is currently being used in an ongoing large-scale RCT and the results are underway ( 106 ).…”

Just know it : The role of explicit knowledge in internet-based cognitive behaviour therapy for adolescents

“…A similar review on ICBT for adolescents with depression reached similar conclusions (Wozney et al, 2017) and encouraged future research to use designs such as factorial designs to evaluate the effect of persuasive components on treatment outcomes. Factorial designs enable researchers to evaluate the unique contribution of different factors within treatments (Watkins et al, 2020), and thus possibly strategies targeting learning of treatment content.…”

“…Taken together, studies show that internet is a suitable format for delivering CBT for adolescents. However, as with adults, the active treatment components in ICBT are still fairly unknown (Andersson, 2018;Watkins et al 2020). We do not know which ingredients or what kind of support that is needed to obtain optimal effects.…”