Comparison of risk factors for the onset and maintenance of depression.
BACKGROUND
Factors associated with depression are usually identified from cross-sectional studies.


OBJECTIVE
We explore the relative roles of onset and recovery in determining these associations.


METHODS
Hazard ratios for onset and recovery were estimated for 39 risk factors from a cohort study of 10,045 general practice attendees whose depression status was assessed at baseline, 6 and 12 months.


RESULTS
Risk factors have a stronger relative effect on the rate of onset than recovery. The strongest risk factors for both onset and maintenance of depression tend to be time-dependent. With the exception of female gender the strength of a risk factor's effect on onset is highly predictive of its impact on recovery.


CONCLUSIONS
Preventive measures will achieve a greater reduction in the prevalence of depression than measures designed to eliminate risk factors post onset. The strength of time-dependent risk factors suggests that it is more productive to focus on proximal rather than distal factors.
Bottomley
Christian
C
Department of Primary Care and Population Sciences, University College London, UK. christian.bottomley@lshtm.ac.uk
Nazareth
Irwin
I
Torres-González
Francisco
F
Svab
Igor
I
Maaroos
Heidi-Ingrid
HI
Geerlings
Mirjam I
MI
Xavier
Miguel
M
Saldivia
Sandra
S
King
Michael
M
D017668:Age of Onset; D003866:Depressive Disorder / Q000453:epidemiology / Q000209:etiology*; D005194:Family Practice; D005260:Female; D006801:Humans; D008297:Male; D015995:Prevalence; D011569:Psychiatric Status Rating Scales; D012307:Risk Factors; D012737:Sex Factors; D013997:Time Factors