He received his medical degree in Toulouse, later working in several mental institutions in France, although these duties were interrupted by the Great War.
[1][2] With his mentor, Paul Sérieux (1864–1947), he contributed on psychiatric publications such as Les Folies raisonnantes (1909) ("The Reasoning of Follies)"[3]) and Les Psychoses à base d'interprétations délirantes (1902) (“Psychoses Based on Delusional Interpretations”).
[4] With Sérieux, he described a type of non-schizophrenic, paranoid psychosis referred to as Delerium of Interpretation with Serieux and Capgras[5].
This disorder is defined as a delusion that a close relative or friend has been replaced by an impostor.
In 1931 Capgras was appointed the president of the Société Médico-Psychologique (The Medical-Psychological Society) for his case studies and journal articles.