Acceptance and commitment therapy applied to early psychosis: Therapeutic foundations and a narrative systematic review

Table 3 Summary of reviewed studies on acceptance and commitment therapy in early psychosis

Ref.	Des.	Participants/samples	Population	Intervention	Conclusions	Results
Vaessen et al[65]	No RCT	n = 16. No control group	People with ultra-high risk (clinically established) or first-episode psychosis	ACT in Daily Life (ACT-DL): A new mobile health treatment protocol for people with early psychosis. The protocol was designed to facilitate the translation of therapeutic techniques learned during in-person ACT sessions into the patient’s daily life	ACT-DL may aid individuals in integrating skills they learn during therapy sessions into their everyday lives. ACT-DL may help early psychosis patients by applying ACT skills to different contexts of everyday life. Adherence to the protocol was relatively demanding	Participants evaluated the overall training (M = 5.63 ± 1.17), the ACT therapy sessions (M = 5.63 ± 1.36), and home exercises (M = 4.81 ± 1.63) as useful. Moreover, participants evaluated the app as useful (M = 4.56 ± 1.69) and reported that it helped them apply the exercises in daily life (M = 4.75 ± 1.71) and made them more aware of their feelings (M = 5.25 ± 1.56)
Van Aubel et al[66]	RCT	Total n = 55. ACT-DL (n = 27). Active control (n = 28)	Young people (16 to 25) with subthreshold depressive and/or psychotic symptoms	ACT-DL through an app	Depressive symptoms decreased more in ACT-DL than in active control. Self-reported symptoms decreased equally in ACT-DL and active control. ACT-DL did not modify PF	Depression scores (rated by the interviewer) decreased among participants in the ACT-DL group compared with controls (P = 0.027)
Myin-Germeys et al[67]	RCT	Total n = 148 ACT-DL + TAU (n = 71) TAU (n = 77)	People with ultra-high risk (clinically established) or first-episode psychosis	Multicenter INTERACT RCT. ACT-DL combines face-to-face therapy with an ecological momentary intervention (EMI)	The study did not support a significant effect of ACT-DL compared to TAU on primary outcomes However, global functioning and psychotic distress were improved in the ACT-DL group	Results showed that Global functioning (χ2 = 9.05; P = 0.033) and negative symptoms (χ2 = 19.91; P < 0.001) improved in ACT-DL compared to TAU, as did psychotic distress (χ2 = 21.56; P < 0.001) measured as EMI
van Aubel et al[68]	No RCT	n = 71. No control group	People with ultra-high risk (clinically established) or FEP	No intervention. Data on treatment engagement with and acceptability of ACT-DL during and after the intervention of ACT-DL. This study is a secondary analysis of the INTERACT trial	The study showed good treatment engagement with and acceptability of ACT-DL in early psychosis. Participants attended an encouraging number of face-to-face sessions and weekly interactions. Results suggested an effective real-world application of ACT techniques. Moreover, ACT-DL improved emotional awareness	The results demonstrated high levels of commitment and participation among the participants, with the majority (n = 42) completing all sessions. In addition, 86% to 96% of subjects rated the sessions and exercises as useful
Chien et al[69]	RCT	Total n = 126. AIM-AT (n = 42) Psychoeducation (n = 42) TAU (n = 42)	Outpatients with psychosis ≤ 3 years’ duration	Acceptance-based intervention plus motivational interviewing to improve medication adherence for people with early psychosis (AIM-AT)	Compared to the other two groups, participants in the AIM-AT experienced significant improvements in primary outcomes (medication adherence and knowledge of the disease). The AIM-AT group was also better in psychotic symptoms, psychosocial functioning, satisfaction with service, duration of hospitalization, and number of patients hospitalized during the follow-up	Compared with psychoeducation and/or TAU, the AIM-AT group had more significant improvements, with moderate to large effect sizes (η2 = 0.07–0.18). Adherence: η2 = 0.18. Insight: η2 = 0.10. Psychotic symptoms (PANSS): η2 = 0.12. Functioning (SLOF): η2 = 0.09. Length of hospitalization: η2 = 0.09
Özer and Dişsiz[7]	RCT	Total n = 53. ACT (n = 26) TAU (n = 27)	People with schizophrenia and other psychotic disorders with less than 3 years of duration	8-session ACT program as an online group therapy	Online group ACT applied to individuals with early psychosis was found to reduce psychotic symptoms and increase their levels of functioning. Hospitalizations were also found to be lower in the intervention group	Differences in post-test and follow-up on symptoms (total PANSS): χ2 = 42.66; P = 0.000. Effect size in between-group differences: Positive symptoms (W = 0.80); Negative symptoms (W = 0.65); General symptoms (W = 0.86). Differences in social functioning: χ2 = 42.67; P = 0.000. Effect size: W = 0.821
Li et al[54]	No RCT	n = 148. No control group	Individuals were at high clinical risk for psychosis or with first-episode psychosis	Data obtained from the INTERACT study baseline assessment, during which all participants completed 6 days of experience sampling assessment of momentary negative affect and assessments of emotion regulation strategy use	The study demonstrated that greater emotion regulation (ER) flexibility predicts more stable negative emotions and faster affective recovery. Findings further provide evidence for ER flexibility in early psychosis, emphasizing the adaptive nature of regulatory flexibility to reduced instability in negative affect (NA) and faster recovery from NA in everyday life	At the intrapersonal level, results show significant associations between lower NA instability and higher ER flexibility (P = 0.049). However, the opposite pattern is observed at the interpersonal level: Higher NA instability is associated with greater ER flexibility (P < 0.001)
Chong et al[70]	RCT	Total n = 72. ACT-LCP (n = 36). Active control (n = 37)	Early psychosis patients	Five-week group program focusing on ACT-based motivation for healthy lifestyles: ACT-based Lifestyle Counselling Program (ACT-LCP)	The ACT-LCP was feasible and acceptable, demonstrating initial efficacy in individuals with early psychosis. Improvements were observed in PF, autonomous motivation, psychotic symptoms, and quality of life at 12 weeks post-intervention	Significant improvements in ACT-LCP participants compared to controls at the 12-month follow-up in terms of physical activity (P < 0.001), autonomous motivation (aMD = 4.74; P < 0.001), psychological inflexibility (aMD = -7.69; P < 0.001), mental state (aMD = -6.83; P < 0.001), and quality of life (aMD = 0.46; P = 0.006)

The table includes only the measures that show a significant effect. SMD: Equivalent to Cohen's d; W: Kendall’s W; η²: Eta squared (effect size); M: mean ± SD; aMD: Adjusted mean difference; ACT: Acceptance and commitment therapy; TAU: Treatment as usual; RCT: Randomized controlled trial; FEP: First-episode psychosis; PANSS: Positive and negative syndrome scale; SLOF: Specific level of functioning scale.

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