Shared genetic contributions to pathological gambling and major depression in men.
BACKGROUND
Although pathological gambling (PG) and major depression (MD) frequently co-occur, little is known regarding the relative contributions of environmental and genetic factors to the codevelopment of the disorders.


OBJECTIVE
To estimate environmental and genetic contributions to PG and MD as defined in DSM-III-R and the lifetime co-occurrence of PG and MD.


METHODS
Survey data from the Vietnam Era Twin Registry were examined in biometric models.


METHODS
Telephone interview.


METHODS
Of 10, 253 eligible participants, 7869 were successfully interviewed.


METHODS
Estimated genetic, shared environmental, and unique environmental contributions to PG and MD and their lifetime co-occurrence in bivariate models.


RESULTS
Elevated odds ratios for MD were associated with those of PG (4.06; 95% confidence interval, 2.68-6.13), and the association remained significant following adjustment for sociodemographic and other psychiatric variables (odds ratio = 1.98; 95% confidence interval, 1.14-3.45). The best-fitting bivariate model indicated that 66% of the variance in PG and 41% of the variance in MD were owing to genetic factors, and 34% of the variance in PG and 59% of the variance in MD were owing to unique environmental factors. There was a substantial correlation between the genetic components of PG and MD (r(A) = 0.58), with 34% of the genetic variance for each disorder also contributing to that of the other. The best-fitting model estimated that 100% of the total overlap between PG and MD was genetic.


CONCLUSIONS
The correlation between PG and MD in middle-aged men appears to be largely influenced by overlapping genetic factors. Future research is needed to determine the extent to which these findings extend to other groups (eg, women), identify specific genes, and generate improved prevention and treatment strategies.
Potenza
Marc N
MN
Department of Psychiatry, Yale University School of Medicine and Connecticut Mental Health Center, New Haven, CT 06519, USA. marc.potenza@yale.edu
Xian
Hong
H
Shah
Kamini
K
Scherrer
Jeffrey F
JF
Eisen
Seth A
SA
D000328:Adult; D015897:Comorbidity; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics*; D004200:Diseases in Twins / Q000175:diagnosis / Q000235:genetics*; D007174:Disruptive, Impulse Control, and Conduct Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics; D005715:Gambling / Q000523:psychology*; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation; D006801:Humans; D008297:Male; D008957:Models, Genetic; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012042:Registries; D019114:Remote Consultation; D012737:Sex Factors; D012931:Social Environment; D013689:Telephone; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic; D014481:United States / Q000453:epidemiology