Precision medicine requires precise evidence-based practice and precise definition of the patients included in clinical studies for evidence generalization. Clinical research exclusion criteria define confounder patient characteristics for exclusion from a study. However, unnecessary exclusion criteria can weaken patient representativeness of study designs and generalizability of study results. This paper presents a method for identifying questionable exclusion criteria for 38 mental disorders. We extracted common eligibility features (CEFs) from all trials on these disorders from ClinicalTrials.gov. Network Analysis showed scale-free property of the CEF network, indicating uneven usage frequencies among CEFs. By comparing these CEFs' term frequencies in clinical trials' exclusion criteria and in the PubMed Medical Encyclopedia for matching conditions, we identified unjustified potential overuse of exclusion CEFs in mental disorder trials. Then we discussed the limitations in current exclusion criteria designs and made recommendations for achieving more patient-centered exclusion criteria definitions.