Final answer:
Emil Kraepelin classified mental disorders and contributed greatly to modern psychiatric diagnoses, but he did not develop psychoanalysis, found behaviorism, or study cognitive psychology.
Step-by-step explanation:
The true statement about the German psychiatrist Emil Kraepelin is that he classified mental disorders. Emil Kraepelin is known for his significant contributions to the understanding of mental illnesses. He developed a comprehensive classification system of mental disorders that influenced modern psychiatric diagnoses. Contrary to the options provided, he did not develop psychoanalysis, as that was Sigmund Freud's contribution. He also was not the founder of behaviorism, which was pioneered by John B. Watson, nor was he specifically known for studying cognitive psychology.