For two years, trials with hospitalized patients found that approximately 70% of those with schizophrenia were markedly relieved from their symptoms. This work earned Kline, along with his colleagues, his first Lasker Award.

Encouraged by his success with this tranquilizer, Kline investigated the properties of antidepressants. Within a year, patients in psychiatric centers throughout the US were receiving antidepressant medication. In 1964, Kline earned his second