The purpose of the study is to examine the feasibility, acceptability and preliminary efficacy of an acceptance-based, insight-oriented treatment approach for US incarcerated adults. Feasibility and acceptability will be assessed through attendance and retention throughout the intervention period. Primary outcomes include negative affect, psychological flexibility, emotion regulation, purpose in life, impulsivity, and trauma. Changes will be assessed from baseline to post-course, post-course to 6-month follow up, and baseline to 6-month follow up for all primary outcomes. Researchers hypothesize that, 1) retention rates will be similar to previous trials with 70% retention from pre- to post-course; 2) there will be significant baseline-to-post-course reductions in psychological symptoms, impulsivity, and trauma, and an increase in psychological flexibility, purpose in life, and emotion regulation; and 3) there will be significant baseline-to-6-month reductions in psychological symptoms, impulsivity, and trauma, and an increase in psychological flexibility, purpose in life, and emotion regulation.

Prevailing correctional counseling methods (e.g., cognitive-behavior therapy, social learning) often operate from an "outside-in" paradigm attempting to put mental health "into" people in prison using various strategies and techniques. Three Principles Correctional Counseling (3PCC), informed by theosophy of Sydney Banks, with a subsequent intervention based on Banks's work, is grounded in a different paradigm-in which all individuals, including incarcerated, have innate positive mental health; however, their belief systems convince them otherwise. When incarcerated individuals learn to navigate daily challenges with mental clarity, affective states shift from negative to positive, allowing for state-dependent positive recall, leading to lower likelihood of responding to negative thoughts and feelings with deviant and other health-damaging behavior.

Studies suggest 3PCC leads to improvements in negative affect such as depression, anxiety, and rumination, and increases in positive outcomes including mindfulness, mental health, social well-being, emotional regulation and non-attachment in non-correctional samples, reductions in stress and anxiety for HIV-positive patients; improvements in substance use problems, criminal justice involvement, employment, housing, and psychological wellbeing for women in in-patient substance abuse treatment; improved resilience in high-risk children and adolescents, improved mental health and resilience in young trauma-exposed sex offenders, improvements in thought recognition, mindfulness, and psychological well-being in a correctional sample, and improved in mental well-being, purpose in life, anxiety and anger, and behavior in a UK prison. 3PCC has also shown feasibility and acceptability in refugee women with trauma, and demonstrated feasible retention rates of 76% in an English prison setting.

The current trial is designed to further assess efficacy of 3PCC in incarcerated individuals. 3PCC classes will be facilitated by practitioners with several years of experience working with diverse client populations. Each 3PCC class will meet weekly for 10 consecutive weeks, with each session approximately 3 hours long. Classes will include the following modules: Building Rapport, Exploration of "Reality"; Separate Realities; Exploration of Thought and Insight; Consciousness-Where Does it Come From?; Exploring Feelings/Moods/Behavior; Exploring Innate Health/Natural Intelligence; What is Mind?; Exploring Infinite Potential; Exploring Mental Clarity Versus a Busy Mind; Stepping into the Unknown, Implications of the Principles for Life in Prison; and Living Outside of Prison.

Hypothesis 1: Compared with the control group, participants in the 3PCC condition will demonstrate significant increases in psychological flexibility, quality of life, clear mind, emotional regulation, impulse control and purpose in life at post-course, which will be maintained at 3- and 6-month follow-up.

Hypothesis 2: Compared with the control group, participants exposed to 3PCC will show significant decreases in depression, anxiety, anger, and trauma symptoms at post-course, which will be maintained at 3- and 6-month follow-up.

Hypothesis 3: Compared with the control group, participants exposed to 3PCC will show greater improvement in behavior within the prison community at post-course, which will be maintained at 3- and 6-month follow-up. Behavior will be measured by prison records measuring participants' behavioral violations and rewards for prosocial behavior.

Inclusion Criteria:

• at least 9 months left in their sentence
• agree to complete assessments at baseline, post-course, and 3 and 6 months following completion of the 3PCC course
• are able to read and write in English.

Exclusion Criteria:

• DOC staff deems it inappropriate for them to participate in the study for clinical or administrative reasons