BackgroundYoung adults with stroke have distinct professional and social roles making them vulnerable to symptoms of post-stroke depression (PSD) and post-stroke anxiety (PSA). Prior reviews have examined the prevalence of anxiety and depression in stroke populations. However, there are a lack of studies that have focused on these conditions in young adults. ObjectiveWe performed a systematic review and meta-analysis of observational studies that reported on symptoms of PSD, PSA and comorbid PSD/PSA in young adults aged 18 to 55 years of age. MethodsMEDLINE, EMBASE, SCOPUS and PsycINFO were searched for studies reporting the prevalence of symptoms of PSD and/or PSA in young adults with stroke from inception until June 23, 2023. We included studies that evaluated depression and/or anxiety symptoms with screening tools or interviews following ischemic or hemorrhagic stroke. Validated methods were employed to evaluate risk of bias. Results4748 patients from twenty eligible studies were included. Among them, 2420 were also evaluated for symptoms of PSA while 847 participants were evaluated for both PSD and PSA symptoms. Sixteen studies were included in the random effects meta-analysis for PSD symptoms, with a pooled prevalence of 31 % (95 % CI 24–38 %). Pooled PSA symptom prevalence was 39 % (95 % CI 30–48 %) and comorbid PSD with PSA symptom prevalence was 25 % (95 % CI 12–39 %). Varying definitions of ‘young adult’, combinations of stroke subtypes, and methods to assess PSD and PSA contributed to high heterogeneity amongst studies. ConclusionsWe identified high heterogeneity in studies investigating the prevalence of symptoms of PSD and PSA in young adults, emphasizing the importance of standardized approaches in future research to gain insight into the outcomes and prognosis of PSD and PSA symptoms following stroke in young adults. Larger longitudinal epidemiological studies as well as studies on tailored interventions are required to address the mental health needs of this important population. FundingNone.