Td. Wade et al., A comparison of family functioning, temperament, and childhood conditions in monozygotic twin pairs discordant for lifetime bulimia nervosa, AM J PSYCHI, 158(7), 2001, pp. 1155-1157
Objective: The authors investigated differences between twins in nine pairs
of female monozygotic twins in the Australian Twin Registry who were disco
rdant for lifetime bulimia nervosa.
Method: The twins affected and unaffected by lifetime bulimia nervosa were
compared on self-report measures, including a measure of parental bonding,
four measures of temperament, and six early-childhood medical conditions.
Results: No twins had current bulimia nervosa, and there was no difference
in weight or eating status between the affected and unaffected twins. The a
ffected twins reported significantly lower self-esteem and less warmth but
more overprotection by their mothers during childhood.
Conclusions: Although limited by the small number of discordant twin pairs
and the inability to detect causal relationships, these results suggest tha
t environmental influences that promote low self-esteem may also increase t
he risk for bulimia nervosa. These temperamental differences may explain th
e discrepancies in parenting or perceived parenting.