Background: The birth-cohort phenomenon of peptic ulcers has remained an unresolved mystery for 60 years since it was first reported in 1962. Currently, peptic ulcers are widely studied as an infectious disease caused by Helicobacter pylori, but this etiology cannot explain this phenomenon. A recently published etiological theory identified peptic ulcers as a psychosomatic disease triggered by psychological stress. This new theory addresses all the characteristics, observations/phenomena, controversies, and mysteries of the disease in a series of 6 articles. Methods: In this fourth article of the series, all the possible causes of peptic ulcers collected from literatures were classified into 3 categories, and the mortality rates caused by these categories were superposed to reproduce the fluctuation curves in the birth-cohort phenomenon. Results: The fluctuation curves in the birth-cohort phenomenon were successfully reproduced, with all the details of the phenomenon elucidated. Psychological stress induced by the First World War accounted for the increasing mortality rates in the early 1910s. The high mortality rates between 1910s and 1940s were maintained by a succession of crucial events that led to extensive psychological stress in the population. The end of the Second World War and continuous improvements in living conditions explained the fall in the early 1950s and afterwards. Conclusions: The birth-cohort phenomenon cannot be fully understood unless peptic ulcers are considered a psychosomatic disease triggered by psychological stress. A full explanation of the birth-cohort phenomenon exemplifies the application of a brand-new methodological concept, superposition mechanism, which can be universally applied to understand any life phenomenon and human disease.

The World Health Organization has developed the Integrated Care of Older People (ICOPE) strategy, a program based on the measurement of intrinsic capacity (IC) as “the composite of all physical and mental attributes on which an individual can draw”. Multicomponent interventions appear to be the more effective approach to enhance IC and to prevent frailty and dependence, being adapted physical activity is the preventive intervention that has shown more evidence in the treatment of frailty and risk of falls. The present study aims to describe the development of a multi-domain group-based intervention addressed to frail older people living in the community aimed to improve and/or maintain intrinsic capacity by means of promoting physical activity, healthy nutrition, and psychological wellbeing in frail older people. We used the GUIDED checklist to describe the development process of AMICOPE (Aptitude Multi-domain group-based intervention to improve and/or maintain IC in frail Older PEople). The intervention was built upon the ICOPE framework and it is described with Template for Intervention Description and Replication (TIDieR) guidelines and it includes dietary advice, cognitive stimulation strategies, medication review, goal setting, and activities to strengthen social support and manage depressive symptoms, as well as strength, balance and flexibility exercise using the Vivifrail program. The study represents the first stage of the UK Medical Research Council framework for developing and evaluating a complex intervention. The next step should be carrying out a feasibility study for the AMICOPE intervention, and in a later stage, assessing the effectiveness in a randomized controlled trial.