A 33-year-old female with recurrent major depressive episodes presents to an outpatient clinic. She has failed two adequate SSRI trials. The PMHNP administers the Mood Disorder Questionnaire (MDQ) as a bipolar screening tool. The patient endorses 8 of 13 symptom items, reports that several of these symptoms occurred during the same time period, and rates the functional impairment as causing 'moderate' problems. Which statement about interpreting this MDQ result is most clinically appropriate?