Validity of the Brief Patient Health Questionnaire Mood Scale (PHQ-9) in the general population.
OBJECTIVE
The aim of this study was to assess the validity of the Patient Health Questionnaire depression module (PHQ-9). It has been subject to studies in medical settings, but its validity as a screening for depression in the general population is unknown.


METHODS
A representative population sample (2,066 subjects, 14-93 years) filled in the PHQ-9 for diagnosis [major depressive disorder, other depressive disorder, depression screen-positive (DS+) and depression screen-negative (DS-)] and other measures for distress (GHQ-12), depression (Brief-BDI) and subjective health perception (EuroQOL; SF-36).


RESULTS
A prevalence rate of 9.2% of a current PHQ depressive disorder (major depression 3.8%, subthreshold other depressive disorder 5.4%) was identified. The two depression groups had higher Brief-BDI and GHQ-12 scores, and reported lower health status (EuroQOL) and health-related quality of life (SF-36) than did the DS- group (P's < .001). Strong associations between PHQ-9 depression severity and convergent variables were found (with BDI r = .73, with GHQ-12 r = .59).


CONCLUSIONS
The results support the construct validity of the PHQ depression scale, which seems to be a useful tool to recognize not only major depression but also subthreshold depressive disorder in the general population.
Martin
Alexandra
A
Philipps-University, Faculty of Psychology, Section of Clinical Psychology and Psychotherapy, Gutenbergstrasse 18, D-35032 Marburg, Germany. martin@staff.uni-marburg.de
Rief
Winfried
W
Klaiberg
Antje
A
Braehler
Elmar
E
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003866:Depressive Disorder / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D005858:Germany / Q000453:epidemiology; D006306:Health Surveys; D006801:Humans; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires