Acceptance and commitment therapy (ACT). The ACT intervention used in this study was designed according to the standards of the Contextual Behavior Science Association (CBSA 2015) and adapted to the needs of the healthy participants. Participants attended a ACT group in place of treatment as usual that would have occurred at the similar time. ACT was delivered by appropriately qualified psychological therapists on an group basis over a period of 3 weeks and included up to 6 h of treatment on an approximately 2 h session per day, with up to one additional booster sessions. A total of four group were made which varied in size from 8 to 10 participants. ACT groups were co-led by two therapists, study analysts included two psychologists and one addictions counselor, each of whom had been conducting ACT groups with substance use disorder patients for at least 2 years. ACT was based on a specific five basic modules (willingness, values, committed action, workability and defusion) and two non-specific targets (stigma and shame). The group sessions were both experiential and didactic, and concentrated on using the processes of psychological acceptance, cognitive defusion, and contact with important values to assist participants learn to respond to their shame or stigmatizing thoughts and behaviors in a way that would not hinder recovery. Acceptance techniques encourage participants to feel problematic feelings more fully while reducing their automatic link to overt action. Cognitive defusion techniques help group members ‘‘deliteralize’’ the content of thoughts – that is, to emphasis more on the process of thinking and the workability of behavior knotted to particular thoughts than on their content. For example, the group generated a particularly potent self-evaluation and reduced it to a single word (e.g., one group arrived at the word ‘‘loser’’). The whole group then repeated that word rapidly out loud for about 30 s, a procedure known to reduce both fusion with thoughts and the distress they induce (Masuda et al. 2004). Mindfulness exercises and metaphors (e.g., watching thoughts like one would watch leaves on a stream) were used to help individuals stay in the present moment and not get ‘‘hooked’’ on thoughts or live in the past or future (Hayes et al. 1999). Participants were encouraged to discover their goals and values in life and to link accomplishment of desired goals to values rather that to automatic thoughts and feelings. A final target of the stigma-combating process is to build a positive agenda of human connection and mutual acceptance. Techniques specific to each targeted process are described in more detail in ACT treatment and self-help manuals (Eifert and Forsyth 2005; Hayes and Smith 2005; Hayes and Strosahl 2005; Hayes et al. 1999).
ACT manual was translated and culturally adapted by study clinician. The translation and cultural adaptation was conducted according to international recommendations and ethics of worthy practice, following 10 steps offered by the International Society for Pharmaco-economics and Outcome Research (ISPOR) (Wild et al., 2005). Steps were (1) preparation, (2) forward translation, (3) reconciliation, (4) back translation, (5) back translation review, (6) harmonization, (7) cognitive debriefing, (8) review of cognitive debriefing results and finalization; (9) proofreading, and (10) final report. Reliability to the treatment protocol was assured by a combination of an initial week of training on the use of the specific model and manual, weekly supervision sessions, and quarterly training days.