Metapsychology
Metapsychology (Greek: meta 'beyond, transcending', and ψυχολογία 'psychology') is a speculative psychology which seeks to understand the structure of the mind in terms which may not be empirically verifiable. Sigmund Freud was the first psychologist to introduce metapsychology. Later on, Frank A. Gerbode started the modern movement of metapsychology which proved to be an effective form of treatment for people suffering from Post-Traumatic Stress Disorder (PTSD). Metapsychology has also been used in different practices and sciences such as biology and mechanics. However, today metapsychology is rarely used but emphasizes a person-centered therapy approach which is closely related to psychoanalysis.