BackgroundThe term “mood stabilizer” is controversial in literature. As there is no consensual meaning, its retirement has been suggested to avoid confusion and misuse. On the other hand, it remains largely employed, and some advocate it carries an important meaning. This issue has not been previously approached using a validated qualitative inquiry.MethodsWe employed document analysis for reviewing proposed definitions for mood stabilizer. Then, we used concept analysis as a qualitative methodology to clarify meanings associated with the term. Based on its results, we built a theoretical model for mood stabilizer, matching it with evidence for drugs used in the treatment of bipolar disorder.ResultsConcept analysis of documents defining the term unearthed four attributes of a mood stabilizer that could be usefully nested into the following ascending hierarchy: “not worsening”, “acute effects”, “prophylactic effects”, and “advanced effects”. To be considered a mood stabilizer, a drug had to reach the “prophylactic effects” tier, as this was discussed by authors as the core aspect of the class. After arranging drugs according to this scheme, “lithium” and “quetiapine” received the label, but only the former fulfilled all four attributes, as evidence indicates it has neuroprotective action.ConclusionThe proposed model uses a hierarchy of attributes that take into account the complexity of the term and help to determine whether a drug is a mood stabilizer. Prophylaxis is pivotal to the concept, whose utility lies in implying a drug able to truly treat bipolar disorder, as opposed to merely targeting symptoms. This could modify long-term outcomes and illness trajectory.