This book explores the interrelatedness between obsessive compulsive disorders, thinking disorders, and depression. The issue is considered both from a psychiatric viewpoint and from a psychodynamic perspective. The age of the cases presented in the book ranges from childhood through adolescence to adulthood.Obsessions: The Twisted Cruelty is a challenging contribution to contemporary clinical debate, especially regarding the role of analytically-oriented psychotherapy in the treatment of OCD, and how to deal with the psychiatric treatment and combine the two approaches, while keeping the focus on the transference-countertransference interplay. After the first theoretical chapter, the relationship between obsessions and thinking impairments is discussed, with specific reference to delusional ideation. A section entitled "the anal conundrum" follows. Encopresis and anal masturbation during childhood are discussed, as well as the identification of the child with a maternal "faecal object. The last section explores the connection with depression, and some specific features of sadism. The author explores the Bionian and post-Bionian perspective on the one hand, as well as developments of the post-Jungian theory, such as the applications of the complexity theory, and the contemporary definitions of complex and archetype. The recent contributions of neuroscience research is also considered.