IFIMAC researchers have introduced a novel approach for treating dissipation in systems with ultrastrong light-matter coupling. In such systems, all states, including the lowest-energy ground state, acquire a mixed light-matter character. The work first demonstrates that the well-known failure of the standard method of treating dissipation, through Lindblad master equations, can be understood as arising from an unphysical negative-frequency contribution in the effective spectrum of the electromagnetic (EM) component. This insight inspires a new way of resolving the problem by including additional auxiliary light modes into the quantum system, which combine to suppress the negative spectral components through destructive interference while maintaining the simple structure of a Lindblad master equation. In this work, published in Physical Review Letters, the authors show that the proposed approach improves on existing state-of-the-art methods, while keeping moderate memory and time consumption, with the additional advantage of being applicable not just to simplified models, but to realistic systems with complex EM mode structures. These findings not only further our general understanding of dissipation in open hybrid systems, but also provide possibilities for future advancements in quantum information technologies. [Full article]