Most research investigating the effect of continuum beliefs on stigma has used weak manipulations which may contribute to mixed findings within the experimental literature. There is also a lack of research into how continuum belief manipulations may impact help-seeking and help-provision. This study used an online manipulation of continuum and categorical beliefs about schizophrenia to examine the subsequent impacts on stigma, help-seeking, and help-provision. A total of 271 participants were randomised into either a continuum, categorical, or control condition. Participants received an informational video, a magazine article, and research highlights relevant to their condition. Prosocial support behaviour was assessed through a novel volunteering measure. The magnitude of change between pre-intervention and post-intervention measures of continuum and categorical beliefs was large. Continuum presentations reduced prognostic pessimism and negative stereotyping. Meanwhile, categorical presentations increased prognostic pessimism. Participants across conditions showed increased help-providing intentions after removing the highest scores to avoid ceiling effects. Fear and blame also decreased significantly across all conditions. There was no difference between conditions on our novel volunteer help-provision measure. Our findings have implications for anti-stigma programs and may help inform the design of future continuum belief manipulations.