In this paper, we examine the relation of loneliness with psychopathology and psychotherapy. More specifically, first, we present interpretations of the long-standing neglect of loneliness by the disciplines of Psychology and Psychiatry. Next, we analyze psychoanalytic and existential views from the clinical field about the associations between loneliness and psychopathology. We focus on narcissistic trauma and incapacity for love, as accompanying aspects of loneliness in many forms of psychopathology. Also, we discuss the role of loneliness in the psychotherapeutic relationship, according to the aforementioned views. Finally, we propose that we should recognize the paradoxical nature of loneliness, which means that this experience has both distressing and beneficial aspects and that apart from being an inescapable universal condition, it may become an index of psychopathology as well. Abstract in this paper we examine the relation of loneliness with psychopathology and psychotherapy. More specifically, first, we present interpretations about the long-standing neglect of loneliness by the disciplines of Psychology and Psychiatry, such as the dominance of the Cartesian spirit, lack of self-knowledge among a number of therapists, the terrifying, and often incommunicable nature of loneliness, the social stigma inherent in this experience, and the collective denial of loneliness. Next, we analyze psychoanalytic and existential views from the clinical field about the associations between loneliness and psychopathology. in severe psychic disorders, loneliness is an extremely distressing and painful experience, with special features, which are discussed. We refer to the common defense mechanisms for dealing with loneliness. We focus on narcissistic trauma and incapacity for love as accompanying aspects of loneliness in many forms of psychopathology. Also, we discuss the role of loneliness in the psychotherapeutic relationship, according to the aforementioned views. Becoming aware of the narcissistic trauma and the early deprivation which are associated with lack and incompleteness as traits of loneliness, finding an optimal distance between the therapist and the patient, searching for an equilibrium between relatedness and separateness, developing the capacity to tolerate separation and the capacity to be alone in the presence of the other are discussed. Moreover, likely pitfalls in the process of reducing the patient's loneliness as well as loneliness in the therapist are analyzed. Finally, we draw some conclusions emphasizing the acknowledgment and acceptance of loneliness by the therapist and patient, the attribution of meaning to it, and the necessity of binding and social bonding. We propose that we should recognize the paradoxical nature of loneliness, which means that loneliness has both distressing and beneficial aspects and that apart from being an inescapable universal condition, it may become an index of psychopathology as well
