Leganés Psychiatric Hospital has been the subject of several studies about its institutional history and clinical activity. The first decades of the twentieth century are the less explored years; however, important events for the development and establishment of the discipline of psychiatry happened in Spain during this period.

To describe the clinical and therapeutic management of inpatients admitted to Leganés National Asylum between 1900 and 1931.

This is a retrospective case series study. We reviewed medical records found in the Historical Archives of Psychiatric Institute, Germany (n = 1043) of inpatients admitted between 1900 and 1931. We analyzed clinical care variables, mainly related to diagnosis and treatment, of the patients who were admitted during this period (n = 1043) with SPSS v21. We consulted bibliography, such as asylum documents and diverse primary and secondary literature.

The diagnosis of mania was very common in the early twentieth century. Lypemania nearly disappeared after 1910 and monomania was not observed in any patient. Delusions decreased after 1905. The first patient diagnosed with schizophrenia was admitted on 19th November 1921. From that moment, the use of this term increased significantly. Only 4.4% of patients admitted underwent treatment.

We confirmed the predominance of French nosology in the early twentieth century. From 1920, an increase in German nosography was observed. The application of treatments was rare.

The authors have not supplied their declaration of competing interest.