Does Mood Disorder Questionnaire identify sub-threshold bipolarity? Evidence studying worsening of quality of life

It is debated whether the Mood Disorder Questionnaire (MDQ) can generate false positives by screening other disorders as bipolar, or identify sub-threshold bipolarity. The aim is to verify if Quality of Life (QoL) impairment in MQD positives in the community is due to MDQ positivity itself, or to psychiatric diagnosis associated with MDQ positivity (supporting the former hypothesis).