Inverse stochastic resonance comprises a nonlinear response of an oscillatory system to noise where the frequency of noise-perturbed oscillations becomes minimal at an intermediate noise level. We demonstrate two generic scenarios for inverse stochastic resonance by considering a paradigmatic model of two adaptively coupled stochastic active rotators whose local dynamics is close to a bifurcation threshold. In the first scenario, shown for the two rotators in the excitable regime, inverse stochastic resonance emerges due to a biased switching between the oscillatory and the quasi-stationary metastable states derived from the attractors of the noiseless system. In the second scenario, illustrated for the rotators in the oscillatory regime, inverse stochastic resonance arises due to a trapping effect associated to a noise-enhanced stability of an unstable fixed point. The details of the mechanisms behind the resonant effect are explained in terms of slow-fast analysis of the corresponding noiseless systems.The effects of noise may generically be classified into two groups: on the one hand, the noise may enhance or suppress certain features of deterministic dynamics by acting on the system states in an inhomogeneous fashion, while on the other hand, it may give rise to novel forms of behavior, associated to crossing of thresholds and separatrices, or to a stability of deterministically unstable states. The constructive role of noise has been evinced in a wide range of real-world applications, from neural networks and chemical reactions to lasers and electronic circuits. The classical examples of stochastic facilitation concern the resonant phenomena, including the stochastic resonance, where the noise of appropriate intensity may induce oscillations in bistable systems that are preferentially locked to a weak periodic forcing, and the coherence resonance, where an intermediate level of noise may trigger coherent oscillations in excitable systems. Recently, a novel form of nonlinear response to noise, called inverse stochastic resonance, has been discovered while studying individual neural oscillators and models of neuronal populations. It has come to light that the noise may reduce the intrinsic spiking frequency of neuronal oscillators, transforming the tonic firing into a bursting-like activity or even quenching the oscillations. Within the present study, we demonstrate two paradigmatic mechanisms of inverse stochastic resonance, one based on biased switching between the metastable states, and the other associated to a noise-enhanced stability of an unstable fixed point. We show that the effect is robust, in a sense that it may emerge in coupled excitable and coupled oscillatory systems, and both in cases of Type I and Type II oscillators. a) Electronic mail: franovic@ipb.ac.rs Noise in excitable or multistable systems may fundamentally change their deterministic dynamics, giving rise to qualitatively novel forms of behavior, associated to crossing of thresholds and separatrices, or stabilization of certain unstab...