Within ACT, the individual will use various forms of Cognitive Fusion to avoid thoughts and behaviours which invoke pain and suffering.
Chronic Experiential Avoidance is toxic. "A large and growing body of research shows that higher experiential avoidance is associated with anxiety disorders, excessive worrying, depression, poorer work performance, higher levels of substance abuse, lower quality of life, high-risk sexual behavior, borderline personality disorder, greater severity of posttraumatic stress disorder (PTSD), long-term disability, and higher degrees of overall psychopathology.
Chronic avoidance is toxic like ignoring a physical cut is toxic. Ignoring the physical cut may help you avoid the pain of disinfectants and stitches, but if you don't treat the wound, it eventually gets infected and ultimately goes septic.