Table 2

Depression (PHQ-9), anxiety (GAD-7) and stress (PSS-4) scores for the New Zealand cohort, compared with published population normative data‡

PHQ-9 ScoreGAD-7 ScorePSS-4 Score
ParticipantsNormsParticipantsNormsParticipantsNorms
Mean (SD)Mean (SD)tMean (SD)Mean (SD)tMean (SD)Mean (SD)t
Total score7.88 (6.4)2.91 (3.5)20.36†6.26 (5.4)2.95 (3.4)15.98†6.31 (3.3)6.11 (3.1)1.58 (p=0.11)
Gender
 Male7.03 (6.2)2.7 (3.5)5.79†5.54 (5.6)2.66 (3.2)4.27†5.94 (3.5)5.56 (3.0)0.91 (p=0.37)
 Female7.94 (6.4)3.1 (3.5)18.71†6.32 (5.4)3.20 (3.5)14.25†6.34 (3.3)6.38 (3.2)−0.334 (p=0.74)
Age groups (years)
 18–2411.73 (6.7)….….9.04 (6.0)….….8.16 (3.0)….….
 25–348.32 (6.1)2.3 (3.2)12.9†6.85 (5.5)2.81 (3.3)9.72†6.65 (3.2)….….
 35–447.34 (6.5)2.6 (3.5)7.35†6.39 (5.6)2.82 (3.3)6.42†6.17 (3.5)….….
 45–546.51 (4.9)2.8 (3.5)8.43†4.79 (4.3)3.14 (3.4)4.27†5.65 (3.1)….….
 55–647.27 (6.2)3.2 (3.5)6.63†5.60 (4.9)3.25 (3.6)4.84†5.59 (3.1)….….
 65–745.21 (5.7)3.3 (3.6)2.29*4.00 (4.4)2.79 (3.2)1.87 (p=0.07)4.87 (3.2)….….
 ≥752.86 (4.3)4.4 (3.9)−1.65 (p=0.12)2.81 (4.2)3.05 (3.4)−0.26 (p=0.8)4.76 (3.1)….….
  • *p<0.05.

  • †p<0.0001.

  • ‡Published population normative data for PHQ-925, GAD-726 and PSS-4.27

  • GAD-7, 7-item Generalized Anxiety Disorder; PHQ-9, 9-item Patient Health Questionnaire ; PSS-4, 4-item Perceived Stress Scale.