Paternal and maternal age as risk factors for psychosis: findings from Denmark, Sweden and Australia.
BACKGROUND
While the association between increased maternal age and congenital disorders has long been recognized, the offspring of older fathers are also at increased risk of congenital disorders related to DNA errors during spermatogenesis. Recent studies have drawn attention to an association between increased paternal age and increased risk of schizophrenia. The aim of the current study was to examine both paternal and maternal age as risk factors for the broader category of psychosis.


METHODS
We used data from three sources examining psychosis: a population-based cohort study (Denmark), and two case-control studies (Sweden and Australia).


RESULTS
When controlling for the effect of maternal age, increased paternal age was significantly associated with increased risk of psychosis in the Danish and Swedish studies. The Australian study found no association between adjusted paternal age and risk of psychosis. When controlling for the effect of paternal age, younger maternal age was associated with an increased risk of psychoses in the Danish study alone.


CONCLUSIONS
The offspring of older fathers are at increased risk of developing psychosis. The role of paternally derived mutations and/or psychosocial factors associated with older paternal age warrants further research.
El-Saadi
Ossama
O
Queensland Centre for Schizophrenia Research, The Park Centre for Mental Health, Wacol, Queensland Q4076, Australia. elsaadio@wph.uq.edu.au
Pedersen
Carsten B
CB
McNeil
Thomas F
TF
Saha
Sukanta
S
Welham
Joy
J
O'Callaghan
Eadbhard
E
Cantor-Graae
Elizabeth
E
Chant
David
D
Mortensen
Preben Bo
PB
McGrath
John
J
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001315:Australia / Q000453:epidemiology; D016022:Case-Control Studies; D003718:Denmark / Q000453:epidemiology; D005192:Family Health; D005260:Female; D006801:Humans; D008297:Male; D008423:Maternal Age; D008875:Middle Aged; D016017:Odds Ratio; D010331:Paternal Age; D011446:Prospective Studies; D011618:Psychotic Disorders / Q000145:classification / Q000453:epidemiology*; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D013548:Sweden / Q000453:epidemiology