Have 1/f noise and (quantum) thermal noise the same physical causes?

Modern models on thermal noise are derived based on the quantum-theoretical fluctuation-dissipation theorem (F-D Theorem). Although lif-noise is apparently a fluctuation phenomenon, it is not (yet?) covered by the F-D theorem. The reason for that could be that the F-D theorem is subject to limiting assumptions that are not met for important experimental setups. It is expected that a rigorous revision of the F-D theorem will not only explain some discrepancies at the high end of the thermal noise spectrum but could also explain lif-noise on a very broad basis.