Western thinking about mental illness, modeled after physical disease, assumes that psychological suffering is abnormal. For example, the DSM-IV uses “clinically significant distress or impairment” to draw the boundary between normal and abnormal. Psychopathology then becomes a target for therapy.

Some mindfulness-based psychotherapies question this entire notion. ACT, for instance, doubts that “health and happiness are the natural homeostatic states of human existence” (Hayes SC et al. Acceptance and Commitment Therapy, 2d ed. New York, NY: Guilford, 2012). This idea points to the apparently high prevalence of mental disorders and ubiquity of garden-variety psychological distress such as loneliness, boredom, and existential questioning (Harris R, Psychother Aust 2006;12(4):2–8). What is “normal” when “abnormal” seems to be the norm?

Along the same lines, ACT also suggests a destructive normality, “the idea that ordinary and even helpful human psychological processes can themselves lead to destructive and dysfunctional results” (Hayes op cit). Said more bluntly, “human suffering predominantly emerges from normal psychological processes” (ibid, emphasis added).

With this in mind, ACT identifies experiential avoidance as the core problem behind various mental disorders and commonplace suffering. This occurs when we identify thoughts, emotions, or impulses as “abnormal” or “problems” and then attempt to rid ourselves of them. Our resulting “emotional control strategies” can become “costly, life-distorting, or harmful” and often only perpetuate our misery, as Russell Harris, MD, described in his 2006 article that provided an overview of ACT.

These assumptions then direct the therapeutic agenda. As Harris described, “In ACT, there is no attempt to try to reduce, change, avoid, suppress, or control these private experiences. Instead, clients learn to reduce the impact and influence of unwanted thoughts and feelings, through the effective use of mindfulness. Clients learn to stop fighting with their private experiences—to open up to them, make room for them, and allow them to come and go without a struggle.”

Thus, unlike traditional cognitive-behavioral therapy, ACT doesn’t pathologize or directly target maladaptive thinking. It works instead on present-moment awareness and connecting with a transcendent self that is, as Harris describes, “unchanging, ever-present, and impervious to harm.”