# Energy dissipation in unitary dynamics

In the context of quantum mechanics it is often (e.g. in several Wikipedia pages, like on Quantum dissipation) stated, that:

"If the time evolution of a system is unitary (e.g. always in the Hamiltonian formalism), then we have no dissipation of energy. To include such energy dissipation, we need something like a Lindblad equation."

As far as I understand the subject, that is wrong. One can have energy dissipation in a unitary time evolution, e.g. if the Hamiltonian is explicitely time dependent. My assumption at the moment is, that a non-unitary time evolution (like with a Lindblad equation) was introduced to describe something like dephasing. Maybe dephasing is related to information/entropy dissipation and the authors had a wrong definition of "dissipation" in this context?

I do not find any references wich explain the subject the way I see it, just the other way round. Is there an expert on the subject who can comment on this?