Background <p>Individuals who do not disclose a potentially traumatic event (PTE) may receive no (or less) event-related social support after victimization. However, it is less clear whether non-disclosure increases the risk of post-event psychopathology.</p> Aims <p>The present study aims to examine the effects of trauma non-disclosure or disclosure on post-event psychopathology in adult victims of PTEs in the general population of a western European country.</p> Method <p>In this prospective study, lack of emotional support along with anxiety and depression symptomatology (ADS) was assessed before participants (<i>N</i> = 1258) experienced a PTE (T1). Twelve months later (T2), following victimization between T1 and T2, PTSD symptoms (PTSS), ADS, and the extent of PTE-related social acknowledgment among disclosing participants were examined. Post-event psychopathology was then compared between non-disclosers (<i>n</i> = 98) and disclosers with high, fairly high, limited, or low levels of PTE-related social acknowledgment (<i>n</i> = 1160).</p> Results <p>Multivariable logistic regression analyses showed that non-disclosers had a higher prevalence of both PTSS and ADS at T2 than did disclosers with high and fairly high levels of PTE-related social acknowledgment. However, non-disclosers reported lower prevalence of PTSS than disclosers with low levels of PTE-related social acknowledgment. Among disclosers, the prevalence of PTSS and ADS at T2 increased when the level of PTE-related social acknowledgment decreased.</p> Conclusions <p>Non-disclosure of trauma is not necessarily detrimental to mental health when compared to the effects of receiving low event-related social acknowledgment following disclosure. Rather than promoting disclosure in general, it would be more beneficial to recommend disclosure only when supportive relationships are present.</p>