1 and Martin J Prince 1 1 Institute of Psychiatry, London Lund, September 2005
1 Background to depression and What did we already know? Why was this worth doing? 2 Study methods and measures 3 What does it all mean? 4 What does it all mean?
What did we already know? Melzer - National Psychiatric Morbidity Study (UK) Common mental disorders (CMD) fell in prevalence after age People who retired early had increased prevalence of CMD until reaching conventional ages In men Organisationally based studies Relationship between mental health and early
Why was this worth doing? is an important source of morbidity (and mortality) throughout the life course. Poor health may affect decisions Poor conditions may affect health
What did we measure? EURO-D scale - validated in the EURODEP study of depression in Europe, current depression. Cut off on EURO-D corresponds approximately to what a clinician would consider a case of depression. Reasons for and feeling about. Demographic variables. Physical health and functioning. Self reported past history of depression.
Female Male 0 20 40 60 80100 Italy Spain Greece 0.15 0.10 0.05 0.00 France Switzerland Austria Density Sweden Denmark Germany The Netherlands 0.15 0.10 0.05 0.00 0 20 40 60 80100 0 20 40 60 80100
Analysis decisions Exclude all those who retired age 40 after age 79 The women who retired age 40 often gave as the sole reason to spend more time with my family. Those people with Missing depression Age less than 50 already excluded from the graph.
Did age at matter? Adjusted for sex (female higher risk of depression), age (older higher), country (Mediterranean higher), past history (higher), marital status (unmarried higher) OR 95% ci 40-44 1.78 1.30 2.43 45-49 1.57 1.22 2.01 50-54 1.25 1.05 1.49 55-59 1.10 0.96 1.26 60-64 1.00 65-69 0.97 0.83 1.13 70-74 0.67 0.42 1.03 75-79 1.63 0.87 2.97
But why did they retire? Reason Alone At all Pension 4821 5320 Own health 1467 1711 Incentive 1018 1250 Redundancy 477 598 Enjoy life 206 581 Time with family 175 411 Other s health 114 191 Synchrony spouse 87 193 None of above 275 Pens + enjoy 113 Pens + own hlth 109 Pens + fam + enjoy 45 Family + enjoy 44 Pens + incent 44 Incent + enjoy 39 Pens + fam 34 Incent + redund 32 Incent + own hlth 30
Can we explain the effect of age at? Adding self perceived health (healthier lower risk of depression), chronic illnesses (no effect) symptoms (more higher), mobility (problems higher), functioning (limitations higher) grip strength (weaker higher) and then reasons for and feeling about
Reasons for and feelings about OR 95% ci Pension 1.11 0.91 1.34 Incentive 1.20 0.95 1.51 Redundant 1.33 1.02 1.74 Own health 1.33 1.08 1.64 Other s health 1.54 1.05 2.23 Synchrony with spouse 1.15 0.73 1.75 Time with family 1.14 0.83 1.55 Enjoy myself 0.92 0.70 1.21 Felt concerned 2.02 1.63 2.51 Felt relief 0.98 0.85 1.14 Both 1.12 0.88 1.42 Neither 1.00
Reasons for and feelings about (continued) is no longer a source of variation. The age effect has disappeared too.
What does it all mean? Fail to replicate Melzer in full analysis. Strengths Variety of social structures Larger sample Women Differences not CMD More, different confounders Limitations May be controlling for variables on the causal path
Past history of depression Poor man s longitudinal study onset of depression an imperfect measure Final digit 0 1 2 3 4 5 6 7 8 9 Frequency 594 101 151 154 138 380 117 152 190 108 Classify as depressed versus the others (never depressed and those with onset after ). Model with and without current depression.
0 50 100 0.030 0.025 0.020 0.015 0.010 0.005 0.000 Italy Spain Greece France Switzerland Austria Density 0.030 0.025 0.020 0.015 0.010 0.005 0.000 Sweden Denmark Germany The Netherlands 0 50 100 0 50 100 first episode of depression
Can we retrodict who was depressed? More likely to be Female Younger, but possible memory effects From The Netherlands or France Currently depressed Retired older, but possible artefact of shortened period at risk Unmarried
Reasons for and feelings about OR 95% ci Pension 0.85 0.70 1.03 Incentive 1.08 0.86 1.34 Redundant 1.18 0.90 1.54 Own health 1.50 1.22 1.84 Other s health 0.85 0.55 1.27 Synchrony with spouse 0.61 0.37 0.95 Time with family 0.70 0.49 0.98 Enjoy myself 0.93 0.71 1.20 Felt concerned 1.25 0.98 1.59 Felt relief 1.34 1.15 1.57 Both 1.67 1.31 2.12 Neither 1.00
Reasons for and feelings about (continued) Models fairly similar if currently depressed are excluded from the dataset so not just reporting issues. Models fairly similar if age at not included in model.
What does it all mean? Strengths Variety of social structures Large sample Limitations Imperfect measurement of previous depression and timing of onset