The successes and difficulties of the QRPA are discussed first. In particular, the sensitivity of the double beta decay matrix elements on the choice of the proper nucleon-nucleon interaction and the corresponding set of single particle energies is described. The generalized seniority shell model is discussed. It is shown that it leads to results similar to the results of QRPA, avoiding, however, some of its problem. The problem of the isospin nonconservation and spurious center-of-mass motion is briefly described.