Levene enrolled at Columbia University and in his spare time conducted biochemical research, publishing papers on the chemical structure of sugars. In 1896 he was appointed as an Associate in the Pathological Institute of the New York State Hospitals, but he had to take time off to recuperate from tuberculosis.
This graph shows the median age of the resident population of the United States from 1960 to 2015. In 2015, the median age of the United States population was approximately 37.7 years.
Affects more than 15 million American adults, or about 6.7 percent of the U.S. population age 18 and older in a given year. While major depressive disorder can develop at any age, the median age at onset is 32.5. More prevalent in women than in men.