Screening questionnaires administered in community samples may allow to early identify suicidal ideation (S.I.). Although the results found in these samples suggest that S.I. behaves like a unipolar trait or a quasi-trait, it is routinely assessed using procedures developed for bipolar traits. Therefore, the main aim of this study is to determine whether there is a basis for modelling S.I. as a bipolar trait, a unipolar trait, or a quasi-trait with two classes of individuals (symptomatic and asymptomatic). In a community sample and mainly at the scoring level, we compare the results provided by fitting three models based on different assumptions: GRM (bipolar traits), LL-GRM (unipolar traits) and FMA (quasi-traits). 773 Spanish participants answered a S.I. and a life satisfaction questionnaires. GRM and LL-GRM provided equivalent results at the structural level, but not at the scoring level, especially in the conditional and marginal accuracy of the estimated scores. While the GRM scores are highly accurate only in a narrow range well above the mean, the LL-GRM scores are highly accurate in a much wider range around the mean. They also have different implications for the prediction of life satisfaction. FMA results suggest that an asymptomatic and a symptomatic class could not be clearly differentiated. In conclusion, LL-GRM would make it possible to accurately measure a larger number of subjects in a community sample than GRM, leaving fewer cases of vulnerable people unidentified. These results should be considered by researchers and professionals when deciding which modellings to use for screening purposes.