Hanna Ratjen is a Registered Psychotherapist and member of the Canadian Association for Psychodynamic Therapy. She is a member of the German Paediatric Society and German Psychoanalytic Society, and is affiliated with the Toronto Institute of psychoanalysis and the Canadian Psychoanalytic Society.

She received medical training with a specialty in pediatrics at Frankfurt/M, Germany, and psychoanalytic training at the Institut für Psychoanalyse und Psychotherapie im Rheinland e.V.

She has been a Clinical Fellow at the Infant Psychiatry Program at the Hospital for Sick Children in Toronto.

Hanna Ratjen has been a representative for the International Psychoanalytic Studies Organization, a member of the web editorial board of the International Psychoanalytic Association, and a member of the editorial board for the German edition of the Journal of International Psychoanalysis.