Alienist (noun)

1. A specialist in the study of mental illness; a psychiatrist.
2. In the 19th century, a medical expert who determined whether a person was insane.

Origin:

Late 18th century; earliest use found in james boswell (1740–1795), biographer and diarist. from french aliéniste, from aliéné + -iste.

Examples:

1. The alienist studied the patient's behavior and found that he was indeed suffering from a severe mental illness.
2. In the 19th century, the job of an alienist was to determine whether an accused criminal was sane enough to stand trial.
3. The alienist carefully observed the patient's symptoms and came to the conclusion that he needed to be institutionalized.
4. The alienist was a well-respected expert in his field, known for his compassionate and insightful approach to mental health.
5. Many of the early theories of mental illness were developed by alienists, who worked tirelessly to understand the nature of psychological disorders.