On the Schroedinger equation in $\mathbb{R}^{N}$ under the effect of a general nonlinear term A. AzzolliniA. Pomponio 35J6058E05nonlinear Schroedinger equationgeneral nonlinearityPohozaev identity In this paper we prove the existence of a positive solution to the equation $-\Delta u + V(x)u = g(u)$ in $\RN,$ assuming the general hypotheses on the nonlinearity introduced by Berestycki and Lions. Moreover we show that a minimizing problem, related to the existence of a ground state, has no solution. Indiana University Mathematics Journal 2009 text pdf 10.1512/iumj.2009.58.3576 10.1512/iumj.2009.58.3576 en Indiana Univ. Math. J. 58 (2009) 1361 - 1378 state-of-the-art mathematics http://iumj.org/access/