Adaptive reaction disorders and depressive reactions are spreading like the common cold, and there is an urgent need for treatment in daily clinical practice where developmental disorders and mental disorders are prevalent. Given the increasing efficacy of medications, if there is stagnation in clinical outcomes, we ought to question the effectiveness of psychotherapy in enhancing personality functions. The efficacy of medications means there is a shield against large fluctuations in personality reactions, so psychotherapeutic interventions aimed at changing personality functions must achieve clear effects. However, this has not been sufficiently accomplished. The cause lies in ineffective assessment. Assessment stops at the diagnostic stage, and there is a lack of prognostic assessment to enable therapeutic progression. Regardless of the diagnosis, therapeutic change is possible. Assessment is the procedure of identifying the factors that can realise this possibility, and psychotherapy is the procedure of actualising it. Case formulation through intake sessions formalises the potential for change through psychotherapy, and comprehensive psychodynamic psychotherapy begins here. A diagnosis must be accompanied by a prognosis that clarifies the possibility of subsequent treatment, but this is lacking in psychiatric psychotherapy. After a diagnosis is given, case formulation clarifies what practical problems are present, what psychological issues they result from, what therapeutic changes psychotherapy could achieve, and what needs to be done to achieve them. It serves as the therapist’s card to clarify the case-specific nature required for a psychotherapy contract.

　Assessment is ineffective because it fails to capture the dynamics of change. It often resorts to inadequate understandings of post hoc assessments or dynamic analysis, resulting in static assessments of how pathological or dysfunctional states are maintained. What is needed is a dynamic assessment that analyses how change is initiated and how it develops. For this, the foundational theory that outlines the path of human system change—that is, growth and development—must also be dynamic. Both Freud and Rogers, who innovatively advanced psychoanalysis and psychotherapy, developed their theories and techniques by capturing the mechanisms of change based on the cutting-edge biology and physics of their time. The leap from classical physics to quantum dynamics in modern times has also advanced the dynamic analysis of human systems. The dynamic axis of human change lies in the ‘maturation’ of growth and development. Maturation is the biological process through which a person achieves sufficient functional development. Each stage—infancy, childhood, adolescence, and adulthood—has distinct phases of maturation, which undergo phase transitions leading to the next stage until death. The dynamics of change also generate resistance through the static forces that counteract the learning processes driving change. Dynamic psychotherapy involves collaborative analytical work that enhances the operational energy of change within this antagonistic interaction of dynamics and static forces. The reactions that emerge when this operational energy increases are what we call ‘joy.’

　How does the joy that marks the milestones of the maturation process arise, and how does it enable the development from the excitement of stimulus-response joy to authentic joy? By reconstructing the theory and techniques through which pleasure principle joy transforms into reality principle joy, we aim to advance the core theory and techniques of dynamic psychotherapy aimed at encouraging human maturation.