<P> After World War II, John Cade, an Australian psychiatrist, was investigating the effects of various compounds on veteran patients with manic depressive psychosis . In 1949, Cade discovered that lithium carbonate could be used as a successful treatment of manic depressive psychosis . Because there was a fear that table salt substitutes could lead to toxicity or death, Cade's findings did not immediately lead to treatments . In the 1950s, U.S. hospitals began experimenting with lithium on their patients . By the mid-60s, reports started appearing in the medical literature regarding lithium's effectiveness . The U.S. Food and Drug Administration did not approve of lithium's use until 1970 . </P> <P> The term "manic - depressive reaction" appeared in the first American Psychiatric Association Diagnostic Manual in 1952, influenced by the legacy of Adolf Meyer who had introduced the paradigm illness as a reaction of biogenetic factors to psychological and social influences . Subclassification of bipolar disorder was first proposed by German psychiatrist Karl Leonhard in 1957; he was also the first to introduce the terms bipolar (for those with mania) and unipolar (for those with depressive episodes only). </P> <P> In 1968, both the newly revised classification systems ICD - 8 and DSM - II termed the condition "manic - depressive illness" as biological thinking came to the fore . </P> <P> The current nosology, bipolar disorder, became popular only recently, and some individuals prefer the older term because it provides a better description of a continually changing multi-dimensional illness . </P>

When was the term bipolar disorder first used