  It is shown that the Bohmian mechanics and the Madelung quantum hydrodynamics
are different theories and the latter is a better ontological interpretation of
quantum mechanics. A new stochastic interpretation of quantum mechanics is
proposed, which is the background of the Madelung quantum hydrodynamics. Its
relation to the complex mechanics is also explored. A new complex hydrodynamics
is proposed, which eliminates completely the Bohm quantum potential. It
describes the quantum evolution of the probability density by a convective
diffusion with imaginary transport coefficients.
