2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/219927In this paper we give necessary and sufficient conditions for spacelike and timelike curves in a conformally flat, quasi conformally flat and conformally symmetric 4-dimensional \textit{LP}-Sasakian manifold to be proper biharmonic. Also, we investigate proper biharmonic curves in the Lorentzian sphere $S^{4}_{1}$.22 pagesDifferential Geometry58C40, 53C42, 53C25text