Cäcilie M. (Anna von Lieben, born Anna von Tedesco; 1847–1900) is the pseudonym of one of Freud's first patients, whom he called in 1890 his “principal client” and in 1897 his “instructress”.
Born into a rich Austrian Jewish family, Anna von Lieben was referred to Freud in the late eighties for help with a long-standing series of nervous disorders. After referring her for a consulation with Charcot, Freud treated her (with some short-term success) through hypnotism, taking her with him to see Hippolyte Bernheim in 1889 in the (unsuccessful) hope that he might be able to work a permanent cure. He also used abreaction for temporary relief of her symptoms, noting however that her sense of guilt and self-reproaches would swiftly return after the treatment sessions.
Her symptoms, including hallucinations and physical spasms, did much to teach Freud about the reality of conversion hysteria; and how to interpret back from physical symptom or hallucination to the underlying (symbolic) emotional meaning it expressed, often by a 'punning' logic.
Freud's later critics have argued that his continuing treatment of Anna, given awareness of her incurability, amounted to using her as a kind of cash-cow.