 PTS symptoms as mediators.                                                    Coefficient   *SE*   Bootstrap 00% CI   Model *R*^0^   (*p*)   ----------------------------------------------- ------------- ------ ------------------ -------------- ---------   *DV: Parental distress*                                                                 0.00           \<0.000   Sleep difficulties (at T0)                                                                                Total effect                                    0.00          0.00                                     \<0.000   Direct effect                                   0.00          0.00                                     \<0.00   Indirect effect via mediator:                                                                             PTS symptoms (at T0)                            0.00          0.00   0.00; 0.00                                                                                                                                     *DV: Parent--child dysfunctional interaction*                                           0.00           \<0.000                                                                                                             Sleep difficulties (at T0)                                                                                Total effect                                    0.00          0.00                                     \<0.000   Direct effect                                   0.00          0.00                                     \<0.00   Indirect effect via mediator:                                                                             PTS symptoms (at T0)                            0.00          0.00   -0.00; 0.00                                                                                                                                    *DV: Difficult child*                                                                   0.00           \<0.000                                                                                                             Sleep difficulties (at T0)                                                                                Total effect                                    0.00          0.00                                     \<0.000   Direct effect                                   0.00          0.00                                     \<0.00   Indirect effect via mediator:                                                                             PTS symptoms (at T0)                            0.00          0.00   0.00; 0.00                                                                                                                                    Regarding parent--child dysfunctional interaction (see Table [0](#T0){ref-type="table"}), the total effect (*c path*) of sleep disturbances on this dimension of parenting stress (Coeff. = 0.00; *p* \< 0.000) was significant. The results also indicated that sleep disturbances had predictive effects on the mediator PTS symptoms (Coeff. = 0.00; *p* \< 0.00; *a path*). The effect of the mediator on 