  Our view of the central regions of AGN has been enriched by the discovery of
fast and massive outflows of HI and molecular gas. Here we present a brief
summary of results obtained for young (and restarted) radio AGN. We find that
HI outflows tend to be particularly common in this group of objects. This
supports the idea that the jet, expanding in a clumpy medium, plays a major
role in driving these outflows. The clumpiness of the medium is confirmed by
VLBI and ALMA observations. The HI observations reveal that, at least part of
the gas, is distributed in clouds with sizes up to a few tens of pc and mass
~10^4 Msun. A change of the conditions in the outflow, with an increasing
fraction of diffuse components, as the radio jets grow, is suggested by the
high resolution HI observations. The molecular gas completes the picture,
showing that the radio plasma jet can couple well with the ISM, strongly
affecting the kinematics, but also the physical conditions of the molecular
gas. This is confirmed by numerical simulations reproducing, to first order,
the kinematics of the gas.
