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We consider a massless minimally coupled self interacting quantum scalarfield coupled to fermion via the Yukawa interaction, in the inflationary deSitter background. The fermion is also taken to be massless and the scalarpotential is taken to be a hybrid, $V(\phi)= \lambda \phi^4/4!+ \beta\phi^3/3!$ ($\lambda >0$). The chief physical motivation behind this choice of$V(\phi)$ corresponds to, apart from its boundedness from below property, thefact that shape wise $V(\phi)$ has qualitative similarity with standardinflationary classical slow roll potentials. Also, its vacuum expectation valuecan be negative, suggesting some screening of the inflationary cosmologicalconstant. We choose that $\langle \phi \rangle\sim 0$ at early times withrespect to the Bunch-Davies vacuum, so that perturbation theory is validinitially. We consider the equations satisfied by $\langle \phi (t) \rangle$and $\langle \phi^2(t) \rangle$, constructed from the coarse grained equationof motion for the slowly rolling $\phi$. We then compute the vacuum diagrammesof various relevant operators using the in-in formalism up to three loop, interms of the leading powers of the secular logarithms. For a closed fermionloop, we have restricted ourselves here to only the local contribution. Theselarge temporal logarithms are then resummed by constructing suitablenon-perturbative equations to compute $\langle \phi \rangle$ and $\langle\phi^2 \rangle$. $\langle \phi \rangle$ turns out to be at least approximatelyan order of magnitude less compared to the minimum of the classical potential,$-3\beta/\lambda$, owing to the strong quantum fluctuations. For $\langle\phi^2 \rangle$, we have computed the dynamically generated scalar mass at latetimes, by taking the appropriate purely local contributions. Variations ofthese quantities with respect to different couplings have also been presented.

Non-perturbative $\langle \phi \rangle$, $\langle \phi^2 \rangle$ and  the dynamically generated scalar mass with Yukawa interaction in the  inflationary de Sitter spacetime