<i>Cinchona</i> bark and quinine as psychiatric treatments in Portugal, 1700-1900.

<i>Cinchona</i> bark and its main medicinal derivative - quinine - are known antimalarials. Until the 20^th century, medicines with <i>Cinchona</i> bark or quinine were the only effective treatment for malaria used on a large-scale. However, <i>Cinchona</i> bark and quinine were also used in other diseases. Regarding psychiatric uses, in Britain, <i>Cinchona</i> bark was recommended in mania (17 th century) and nervous diseases (18 th century). Nevertheless, the full scope of <i>Cinchona</i> bark and quinine's proposed activity in psychiatric disorders has not been assessed. We aimed to investigate references to <i>Cinchona</i> bark and quinine's use and recommendation in psychiatric diseases and symptoms in Portugal, published in the 18^th and 19^th centuries. For this purpose, we reviewed Portuguese medical and pharmaceutical literature from this period. Our sources included books (namely pharmacopoeias) and periodical publications. We found 27 <i>Cinchona</i> bark or quinine medicines recommended in the treatment of psychiatric diseases and symptoms in Portugal. Those diseases included hysteria, hypochondria, and nervous diseases. <i>Cinchona</i> bark and quinine medicines were also advised in psychiatric symptoms such as anxiety-induced palpitations, melancholia, or hypochondriac or hysterical symptoms. For most of these medicines - 17 out of 27 - the authors mention their efficacy in clinical practice. Consequently, our research suggests that, in 18^th and 19^th -century Portugal, <i>Cinchona</i> bark and quinine medicines were a therapeutic option in various psychiatric conditions. Therefore, it is possible that <i>Cinchona</i> bark and quinine had additional therapeutic indications that remain unknown.