  We discuss weather the new enhancements found by BES, alias the $Y(4220)$,
$Y(4260)$, $Y(4360)$, and $Y(4390)$ are true resonances. We argue that the
nearby thresholds $D_s^*\bar{D}_s^*$, $D\bar{D}_1+\bar{D}D_1$,
$D_s\bar{D}_{s1}+\bar{D_s}D_{s1}$ and $D^*\bar{D}_1+\bar{D}^*D_1$, as well as
the $\psi(4160)$ and $\psi(4415)$ states have a strong influence over the
observed $ J/\psi \pi^+\pi^-$ and $h_c \pi^+\pi^-$ line-shapes. We propose an
unitarized effective Lagrangian model to study the dynamical effect of the
interaction between each known $\psi$ state and its closest thresholds. In
addition, we present some of our recent motivating results, using the same
model, for the $\psi(3770)$ resonance, where the distortion from a Breit-Wigner
line-shape is shown to result not only from the kinematic interference, but
also from the influence of the $D^0\bar{D}^0+D^+D^-$ one-loops. Moreover, two
poles were found, at about 3.78 GeV and at 3.74 GeV, the second one generated
dynamically, yet contributing to the distortion of the line-shape.
