Psychological development progresses through interactions of the self with the other from the beginning of life. R. Hobdell cites S. H. Foulkes as the earliest author on the subject. In the literature on combined therapy one encounters terms which are used with different meanings. Some reserve the term 'combined' only for the case where both therapeutic modalities are delivered by the same therapist while others consider therapies which are concurrent or even sequential as combined. Combined therapy is a rather more open system than unimodal therapy and therefore lends itself more easily to the enactment of affectionate, sexual or aggressive feelings. Combined therapy is often thought as a mode of treatment that is more 'expensive' than unimodal therapy. Equally important to the selection of patients is their preparation for combined therapy. B. Boswood highlighted the need for the establishment of a good 'bond' between therapist and patient if therapy is to be sustained.