Introduction: The Anxiety, Depression and Mood Scale (ADAMS), a mental health screening tool developed for individuals with intellectual disabilities, has yet to be evaluated in adults with Down syndrome. We included the ADAMS in a Dementia Protocol. Method: We reviewed the charts of 71 adults with Down syndrome seen in a specialty clinic and collected ADAMS data from our quality improvement project. We evaluated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the ADAMS at five cutoff points to identify optimal screening thresholds for adults with Down syndrome. Results: Cutoff points set at two points below the 75th percentile scores of the original ADAMS publication presented optimal sensitivity of 81.82%, specificity of 82.93%, PPV of 72.00% and NPV of 89.47%. Conclusion: For adults with Down syndrome, we suggest alternate thresholds, generally two points below the original ADAMS thresholds, to adequately capture mental health concerns.