Set shifting and central coherence as neurocognitive endophenotypes in eating disorders: a preliminary investigation in twins.
OBJECTIVE
Weak central coherence and poor set shifting are risk markers for eating disorders that are present post recovery and in first degree relatives. The aim of this study was to examine these traits in twins with eating disorders.


METHODS
Neuropsychological tests were administered to 114 female twins (n = 53 met lifetime DSM-IV eating disorder criteria, n = 19 non-eating disorder cotwins and n = 42 controls). Within pair correlations for monozygotic (MZ) and dizygotic (DZ) twins were calculated and generalised estimating equations (GEE) compared probands, with non-eating disorder cotwins and controls.


RESULTS
The genetic basis was highest for the central coherence tasks (Rey-Osterrieth Complex Figure Task: MZ twins r = 0.44 [CI: 0.07-0.70, P = 0.01] and Group Embedded Figures Test: MZ twins r = 0.58 [CI: 0.26-0.79, P = 0.00]). Poor set shifting was related to obsessive compulsive symptoms in both individuals with eating disorders and their non-eating disorder cotwins (r = 0.2-0.5).


CONCLUSIONS
Set shifting abilities and central coherence appear to be endophenotypes associated with eating disorders.
King's College London, Institute of Psychiatry, Psychological Medicine, Section of Eating Disorders, London, UK. Natalie.kanakam@kcl.ac.uk
Natalie
N
Kanakam
Charlotte
C
Raoult
David
D
Collier
Janet
J
Treasure
D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D003071:Cognition; D004200:Diseases in Twins / Q000523:psychology*; D058068:Endophenotypes; D001068:Feeding and Eating Disorders / Q000523:psychology*; D005260:Female; D006801:Humans; D007406:Interview, Psychological; D008875:Middle Aged; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D060685:Sense of Coherence; D014429:Twins, Dizygotic / Q000523:psychology; D014430:Twins, Monozygotic / Q000523:psychology; D055815:Young Adult