Henry J Whitfield

Henry J Whitfield, MSc

Regents University London

A longitudinal multiple baseline investigation of psychedelic integration using Acceptance and Commitment Therapy


The integration phase of psychedelic therapy remains the one of the least understood in terms of empirical data, and is essential if modern psychedelic therapy is to deliver lasting benefits. Furthermore, documented reports suggest relapse is common (Wates, 2018). Multiple baseline research methods for examining inner and outer behaviour change on a daily basis may help elucidate how patients succeed and fail to integrate their psychedelic therapy experiences. This ABC multiple baseline study where ‘B’ was a psychedelic ceremony and ‘C’ was Acceptance and Commitment Therapy (ACT) tracked the progress of 21 participants in two cohorts with daily, and weekly measures over a two-three month period. These quantitative measures were also cross-correlated with qualitative data taken in the form of 4 interviews at A,B,C and at 6 months follow up and shared journalling data. The study results suggest evidence for a ‘spiked’ increase – followed by immediate decrease in 1) entanglement with thoughts, and 2) openness to inner experience, as a precursor to increased values-driven behaviour. This was observed in cases of generalised anxiety, social anxiety, diet change to vegetarianism, self-worth, and decreased alcohol use. In another case, ongoing work stresses were an apparent barrier to successful integration. This study also provided data on the performance of multiple measures during psychedelic integration, namely the: Valuing Questionaire (Smout, 2014), Brief Acceptance Measure (Gillanders, unpublished), 3D – Reno Inventory of Self Perspective for tracking changes – tracking changes in the conceptualised self (Jeffcoat, 2015). Many extraneous factors were found to influence these measures, reported during the therapy. Daily measures also helped inform the therapy, thus bringing the barriers into the work. Improving future measurements will be also discussed. We will also consider client accounts of how a new ACT integration model might enhance or build upon progress during a psilocybin retreat. Further studies and even longer term data will be required before we can better understand psychedelic integration and its multiple pitfalls and workable solutions. Inadequacies in this study point to different daily and weekly measures we might consider for future psychedelic multiple baseline studies, as well as improving methods for collecting such data.


Henry Whitfield is an Association of Contextual Behavioural Science (ACBS) Peer-reviewed Acceptance and Commitment Therapy trainer, an Accredited Advanced TIR (PTSD therapy) Trainer and Cognitive Behavioural Psychotherapist (MSc – CBT). For over seven years Henry ran and supervised brief therapy for PTSD projects for Victim Support and Mind in London gun crime hot spots, using CBT and TIR. He has also conducted an RCT comparing trauma approaches for Mind and Single Case Design research for Regent’s University, examining how ACT processes may mediate outcomes. He is also a passionate integral thinker, publishing journal articles and book chapters on the integration of therapeutic models including, REBT-mindfulness, ACT-TIR-CBT, Person-centred-TIR. He has written, co-written and edited training manuals for ACT, TIR and FAP (relational psychodynamic). Now he focuses his research on the development of ACT-consistent models for psychedelic integration, with psychedelic process research for Regents University London.



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