Cardiff depression study. A sib-pair study of life events and familiality in major depression.
BACKGROUND
An excess of both depression and undesirable life events in first-degree relatives of probands with depression as compared with controls has been reported. This association may have reflected a familial factor in common.


OBJECTIVE
To examine the familiality of life events and depression and whether there may be a common familial factor influencing vulnerability to depression and the experiencing of life events.


METHODS
In a sib-pair design, 108 probands with depression and their siblings were compared with 105 healthy controls and their siblings for psychopathology and life events.


RESULTS
The lifetime relative risk of depressive disorder in the siblings of depressed subjects as compared with siblings of controls was 9.74, although these groups did not differ in the life events measures. Several categories of events showed significant sibling correlations, but this was due to the same event affecting both members of the pair.


CONCLUSIONS
Although depressive disorder was strongly familial, the familial effects on life events were largely explained by shared experiences. There was no evidence for a common factor influencing both depression and life events.
Farmer
A
A
Social, Genetic and Developmental Psychiatry Research Centre, Institute of Psychiatry, Denmark Hill, London.
Harris
T
T
Redman
K
K
Sadler
S
S
Mahmood
A
A
McGuffin
P
P
D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D003866:Depressive Disorder / Q000235:genetics* / Q000523:psychology; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008016:Life Change Events; D008297:Male; D008875:Middle Aged; D010551:Personality; D012307:Risk Factors; D012309:Risk-Taking