Shortly thereafter he was appointed as a psychiatric consultant to the Metropolitan Hospital in East Harlem and the Court of Special Sessions in Manhattan where he became active in the treatment drug addicts.

The result was a house on Greens Farm Road, Westport, Connecticut, directed by Jack Hurst, former president of Synanon in Santa Monica.

[5] In the summer of the same year, Casriel became the psychiatric consultant for the Daytop Lodge project on Staten Island, a kind of half-way house for the rehabilitation of convicted felons who were addicts.

The German psychiatrist Dr. Walther H. Lechler became one of his students and later employed the ideas extensively in the development of the Herrenalb Model[9] of psychotherapy used at the hospital of the same name in South Germany.

Expanding on Horace Mann's focus on the pursuit of happiness as a universal human desire, Casriel theorized that the emotion of love comes from the anticipation of pleasure.

[11] Based on Casriel's theory, "bonding," which he defined as "the unique combination of emotional openness and physical closeness with another human being," is central to sustaining healthy, intimate relationships.

Casriel taught that symptoms of bonding deprivation include: "illness, fatigue, depression, rigidity, constriction, isolation, and the range of anti-social behaviors such as drug and alcohol abuse, gambling and sex addictions."