His study brings together the fields of Caffeine and Internal medicine. His Disease study often links to related topics such as Cognitive decline. His work on Disease expands to the thematically related Cognitive decline. He merges Dementia with Atrophy in his research. John Neuhaus conducted interdisciplinary study in his works that combined Atrophy and Dementia. The study of Endocrinology is intertwined with the study of Hippocampal formation in a number of ways. His work in Hippocampal formation is not limited to one particular discipline; it also encompasses Endocrinology. He combines Psychiatry and Neurology in his studies. He applies his multidisciplinary studies on Neurology and Psychiatry in his research.