Dominant mutations in unrelated genes cause fronto-temporal lobar degeneration with TDP-43 inclusions (FTLD-TDP) and include VCP, which is associated with multisystem proteinopathy (MSP). Conditional inactivation of VCP in postnatal forebrain neurons (VCP cKO) caused cortical brain atrophy, neuronal loss, autophago-lysosomal dysfunction, TDP-43 inclusions and hyperactivity. Quantitative proteomics and single nuclei RNA sequencing on VCP cKO brains identified synaptogenesis and the unfolded protein response as the most decreased and increased pathways respectively. Conditional expression of a single MSP disease mutation, VCP-R155C, in cortical neurons similarly recapitulated features of VCP inactivation and FTLD-TDP. Comparison of transcriptomic and proteomic datasets from genetically defined FTD patients revealed that profiles from GRN carriers were similar to VCP insufficiency. These data support a deficiency in VCP dependent functions as the pathogenic mechanism of FTLD-TDP and reveal an unexpected pathogenic similarity with progranulin deficiency. Enhancing VCP function may be therapeutic in MSP and related forms of FTLD-TDP.