Let u be a hermitian linear functional defined in the linear space of Laurent polynomials and F its corresponding Carathéodory function. We establish the equivalence between a Riccati differential equation with polynomial coefficients for F , zAF ′ = BF 2 + CF + D and a distributional equation for u, D(Au) = B 1 u 2 + C 1 u + H 1 L, where L is the Lebesgue functional, and the polynomials B 1 , C 1 , D 1 are defined in terms of the polynomials A, B, C, D .