Since the dawn of human Society, Thought has taken a fundamental role in Society. The ancient Greek world created the basis of modern Medicine. This concept is evident in Psychiatry and every field of Medicine and Surgery, not just in terms of the vocabulary and scientific nomenclature but also in the method of investigation and pathology management. This overview aims to evaluate and enhance evidence derived from the current scientific literature that the Ancient Greek world has significantly influenced modern Medicine. Furthermore, we aimed to highlight differences in the treatment and awareness in the past compared with the Modern world. The perception of disease was profoundly different from today due to the lack of scientific knowledge in ancient times. This article has extensive use of primary sources and original texts to analyze the influence of Greek thought on modern Psychiatry. In light of these results, it is essential to highlight the richness of Greek culture regarding medical knowledge, and above all, the observation of mental disease and patient care.