  We obtain a decomposition formula of a representation of Sp(p,q) and
  SO^\ast(2n) unitarily induced from a derived functor module, which enables us
to reduce the problem of irreducible decompositions to the study of derived
functor modules. In particular, we show such an induced representation is
decomposed into a direct sum of irreducible unitarily induced modules from
derived functor modules under some regularity condition on the parameters. In
particular, representations of SO^\ast(2n) and Sp(p,q) induced from
one-dimensional unitary representations of their parabolic subgroups are
irreducible.
