For a graph G ¼ (V,E), a double Roman dominating function ðDRDFÞf : V ! f0, 1, 2, 3g has the property that for every vertex v 2 V with f(v) ¼ 0, either there exists a vertex u 2 NðvÞ, with f(u) ¼ 3, or at least two neighbors x, y 2 NðvÞ having f(x) ¼ f(y) ¼ 2, and every vertex with value 1 under f has at least a neighbor with value 2 or 3. The weight of a DRDF is the sum f ðVÞ ¼ P v2V f ðvÞ. A DRDF f is called independent if the set of vertices with positive weight under f, is an independent set. The independent double Roman domination number i dR ðGÞ is the minimum weight of an independent double Roman dominating function on G. In this paper, we show that for every graph G of order n, i r3 ðGÞ À i dR ðGÞ n=5 and iðGÞ þ i R ðGÞ À i dR ðGÞ n=4, where i r3 ðGÞ, i R ðGÞ and i(G) are the independent 3-rainbow domination, independent Roman domination and independent domination numbers, respectively. Moreover, we prove that for any tree G, i dR ðGÞ ! i r3 ðGÞ.