Consider the simple screw: cognitive science, quality improvement, and psychotherapy.

Psychological therapy based on cognitive science advances as psychological states can be precisely measured. This article describes a treatment approach, personal quality improvement (PQI), that draws on (a) the states of mind (SOM) model, a mathematical model built on cognitive assessment research on the balance of positive and negative thoughts and feelings; (b) total quality control, a method for improving quality as defined by increased system stability by empowering average workers to reduce variability through process monitoring; and (c) the phase model of psychotherapy, a framework that proposes 3 distinct stages of treatment. In a single-case study, a depressed client used PQI to track emotional, self-image, and optimism balance, achieving an improvement trajectory consistent with the SOM and phase models. PQI emphasizes process, uses a patient focused treatment paradigm that provides tools for autonomous functioning, and allows for calibration of psychological measures.