From Diagnostic Label to Case Formulation: Integrative Reasoning in Clinical Psychology

The value of a diagnosis lies in making complex clinical presentations recognisable and communicable. Its limitations begin when the diagnostic category is treated as an explanation of the person. This conceptual paper examines the relationship between diagnostic classification and individual case formulation in clinical psychology, using a set of clinical-psychology teaching questions prepared in 2012 as its historical point of departure. The paper is not an empirical study and does not claim that the original teaching material documents clinical practice. Within a literature cutoff of 2011, it considers the functions and limitations of ICD-10 and DSM-IV-TR, the biopsychosocial model, cognitive-behavioural and other formulation traditions, evidence-based assessment and common reasoning errors. A structured account of presenting, predisposing, precipitating, perpetuating and protective factors is developed as a practical heuristic, not a validated diagnostic instrument. Fictional teaching illustrations concerning alcohol dependence, depression, anxiety and personality difficulties show how a syndrome-level description may coexist with different hypotheses about maintaining processes. The paper also examines collaboration, clinical uncertainty, formulation quality, intervention selection and revision when predictions fail. The central position is that diagnosis and formulation are complementary but non-equivalent: the former standardises descriptive recognition, while the latter generates individual, revisable and contextually sensitive working explanations. Neither should substitute for appropriate medical assessment, professional judgement or direct attention to safety. Web: https://dkk.hqici.com Web: https://www.hqici.com Keywords: clinical psychology diagnostic classification case formulation biopsychosocial model evidence-based assessment ICD-10 DSM-IV-TR clinical reasoning five Ps diagnostic reasoning