The French Social Security has highlighted psychiatric diseases as a major risk. However, French private health insurance companies do not consider psychiatric care as an important topic. In this article is presented a study (based on four real health insurance databases) of the cost of a policyholder benefiting from a psychiatric follow-up care. It aims to provide a better understanding of this risk in an insurance context. It is shown that such a policyholder costs twice as much as an average policyholder, notably due to important expenses in hospitalization. Policyholders aged from 15 to 30 years, as well as the ones over 70 years old are the most concerned by this risk.