Psychedelics and the new behaviourism : considering the integration of third-wave behaviour therapies with psychedelic-assisted therapy, Zach Walsh and Michelle S. Thiessen, 2018

Psychedelics and the new behaviourism : considering the integration of third-wave behaviour therapies with psychedelic-assisted therapy


Zach Walsh and Michelle S. Thiessen




This narrative review examines evidence related to the potential for third wave behaviour therapies to serve as adjuncts to psychedelic-assisted therapy. It identifies shared theoretical foundations for both approaches, and notes enhanced mindfulness, decentering, emotion regulation, and distress tolerance as common mechanisms of action. It also identifies potential targets for which both approaches have demonstrated therapeutic potential, including problematic substance use, self-directed and other directed violence, and mood disorders. Based on these commonalities, there is a call for research on the potential integration of psychedelic-assistedtherapy and third wave behaviour therapies including Dialectical Behaviour Therapy, Acceptance and Commitment Therapy, and Mindfulness Based Cognitive Therapy.

KEYWORDS : Psychedelics; psychedelic-assisted psychotherapy; hallucinogen; behaviour therapy; third wave; dialectical behaviour therapy; acceptance and commitment therapy; and mindfulness based cognitive therapy


The past decade has seen growing empirical support for a group of psychological interventions collected
under the umbrella of third wave behaviour therapy (TWBT). Examples of TWBT include Dialectical
Behaviour Therapy (DBT: Linehan, 1993), Acceptance and Commitment Therapy (ACT: Hayes, Strosahl, & Wilson, 1999), Mindfulness Based Cognitive Therapy, and several other less widely-adopted approaches (e.g. Functional Analytic Psychotherapy; Kohlenberg & Tsai, 1991; Behavioural Activation; Martell, Addis, & Jacobsen, 2001). Common features of these distinct therapies include emphases on mindfulness and acceptance within a radical behaviourist framework that highlights the natural occurrence of behavioural events, and the importance of other events (e.g. precedents, consequences) in understanding and analysing behaviour (Baum, 1995; Hayes, 2004). In the present review we propose that commonalities in theoretical underpinnings, mechanisms of action, and clinical targets may facilitate the combination of psychedelic therapies and TWBT.

The designation of TWBT emerged in 2004 to describe a group of approaches that built on traditional behavioural therapies by adding emphases on mindfulness, acceptance, dialectics, and spirituality (Hayes, 2004). The term third wave locates TWBT as building on the second wave, cognitive-behavioural therapies (CBT) that added a focus on thoughts and information processing to first wave therapies (Thoma, Pilecki, & McKay, 2015). The TWBT add to previous waves in meaningful ways, but, nonetheless, align with the traditions of behaviour therapy through a foundation in functional analysis, and an emphasis on directly expanding behavioural repertoires through experiential methods. The boundaries of what comprises TWBT are open to debate; however, a recent review by Dimidjian et al. (2016) identified 17 approaches that had been identified as ‘third wave’, of which Acceptance and Commitment Therapy (ACT; Hayes et al., 1999), Dialectical Behaviour Therapy (DBT; Linehan, 1993), and Mindfulness- Based Cognitive Therapy (MBCT; Segal, Williams, & Teasdale, 2002) had been cited at least 20 times in the context of TWBT. To manage the scope of the present review we will limit our focus to these three most comprehensively researched TWBT—ACT, DBT, and MBCT. The review also indicated that scientific interest in TWBT has increased dramatically over the past decade, growing from fewer than 10 mentions in 2005 to over 140 in 2015.

The classification TWBT was first proposed by Steven Hayes, founder of ACT, which is an acceptance and mindfulness based intervention that exemplifies TWBT. ACT differs from second wave CBT by encouraging non-judgemental acceptance of thoughts and feelings, especially distressing ones, rather than challenging or changing the content of internal experiences. ACT has been the subject of considerable empirical study, with several meta-analyses concluding that it is superior to a variety of control conditions for treating addiction, depression, and other psychological disorders (e.g. Hayes, Luoma, Bond, Masuda, & Lillis, 2006; €Ost, 2014; Ruiz, 2012). Together with ACT, DBT is the other most widely studied and applied TWBT (Dimidjian et al., 2016). DBT was initially developed as an intervention for chronically suicidal individuals, and contextualizes behavioural change as existing within a dialectical framework of acceptance and change (Linehan, 1993). Standardized DBT treatment consists of four skills-based modules, with mindfulness and distress tolerance described as acceptance strategies, and emotion regulation and interpersonal effectiveness comprising the change strategies. DBT has garnered considerable empirical support as a treatment for suicidal behaviour, borderline personality disorder, and problematic substance use (Linehan et al., 1999, 2006; McMain et al., 2009). The third most investigated TWBT is MBCT, which, unlike the more broadly applicable ACT and DBT, was developed specifically as a relapse prevention programme for depressive disorders (Segal et al., 2002). MBCT integrates behavioural therapy with mindfulness meditation based on Mindfulness-Based Stress Reduction (Crane et al., 2017; Kabat-Zinn, 2003), and seeks to build skills such as decentering—the metacognitive capacity to observe one’s thoughts and adopt varying perspectives on subjective experience (Bernstein et al., 2015)—to enable the client to skillfully respond to negative thoughts (Teasdale et al., 2002).

A distinctive feature of TWBT is the explicit integration of practices from spiritual and contemplative practices. Indeed, Marsha Linehan, the founder of DBT, has described her approach as a ‘behavioural
translation of Zen’ (Van Nuys, 2007) and notes the influence of her Buddhist training in the development
of the dialectical model that underlies DBT. Similar influences are also evident in the ACT conceptualization of psychological suffering as emerging from attachment to internal experiences (Fung, 2015) and, in MBCT, which foregrounds the development of a meditation practice for both clients and therapists (Segal et al., 2002). The influence of such practices in TWBT represents an avenue of potential convergence with the modern traditions of psychedelic-assisted therapy and personal development (e.g. Dass, 1971; Leary, Metzner, & Alpert, 1964; see Badiner & Grey, 2002 for a review), and prominent Buddhist teachers have noted the influence of psychedelics in initiating and expanding meditiative practices in North America (Kornfield, 2011). Indeed, the convergence of psychedelic self-exploration and key elements of TWBT suggest an informal and non-clinical precedent for the compatibility of these approaches.