The approach is always time-limited, typically taking place over 8-24 weekly sessions (the precise number being agreed at the start of therapy). Sixteen sessions is probably the most common length. In the first quarter of the therapy (the Reformulation phase) the therapist collects all the relevant information, asking the patient about present day problems and also earlier life experiences. At that point the therapist writes a reformulation letter to the client. This letter summarises the therapist's understanding of the client's problems. Particular attention is given to understanding the connection between childhood patterns of behaviour and their impact on adult life. The letter is agreed between patient and therapist and forms the basis for the rest of the work.