Fourth of six programmes penetrating the private world of a family in therapy.

Seventeen-year-old Sara has had a great week; for her the therapy seems to be working. But 21-year-old Rachel has not. Rivals as always, the sisters become locked in an argument which dominates the family's fifth session together. Dr Asen insists that, for once, the parents leave their daughters alone to sort out their differences, and wonders whether the parents actually need and encourage their daughters' difficulties.