From the 1920s until the 1960s the predominant model of social work intervention was psycho-social casework. This model was based on the work of Sigmund Freud and the psychoanalysts.
Psychoanalytic social work emphasised relationship-focussed intervention with the professional adopting the role of the 'expert'. In this approach the client's problems were viewed as fundamentally psychological in nature, and linked to internal psychodynamic factors such as faulty 'ego functioning'. Work with clients tended to be long-term — up to 18 months — and open-ended in nature. Improvement in client's difficulties was often slow, hard to quantify, and in some cases deterioration in their condition was observed.