Differential parenting and risk for psychopathology: a monozygotic twin difference approach.
OBJECTIVE
Consistent and non-specific associations have been found between parenting style and major depression, anxiety disorders, and externalizing behavior. Although often considered part of twins' shared environment, parenting can also be conceptualized as non-shared environment. Non-shared environmental influences have important effects on development but are difficult to test and sort out because of the possible confounding effects of gene-environment interactions and evocative gene-environment correlations. The monozygotic (MZ) differences approach is one way to analytically investigate non-shared environment.


METHODS
The aim of the present study is to use the MZ differences approach to investigate the relationship between differential parenting among 1303 twin pairs (mean age 36.69 ± 8.56) and differences in total symptom counts of major depression (MD), generalized anxiety disorder (GAD), conduct disorder (CD), and anti-social behavior (ASB) during adulthood.


RESULTS
Although effect sizes tended to be small, a number of results were significantly different from zero. Perceived differences in parental coldness was positively associated with internalizing disorders. Differences in protectiveness were negatively associated with MD, GAD, and ASB. Differences in authoritarianism were positively associated with MD and CD, but negatively associated with ASB.


CONCLUSIONS
Perceived differences in parenting style are associated with differences in MD, GAD, CD, and ASB outcomes in a sample of MZ twins. Despite the lack of a basis for making causal inferences about parenting style and psychopathology, these results are suggestive of such a relationship and show that non-shared environmental influence of parenting does in some cases significantly predict adult psychopathology.
Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, P.O. Box 980126, Richmond, VA, 23219, USA. longe@vcu.edu.
E C
EC
Long
Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, P.O. Box 980126, Richmond, VA, 23219, USA.
S H
SH
Aggen
Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, P.O. Box 980126, Richmond, VA, 23219, USA.
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Gardner
Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, P.O. Box 980126, Richmond, VA, 23219, USA.
K S
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Kendler
D000328:Adult; D001008:Anxiety Disorders / Q000453:epidemiology*; D001318:Authoritarianism; D019955:Conduct Disorder / Q000453:epidemiology*; D003865:Major Depressive Disorder / Q000453:epidemiology*; D004200:Diseases in Twins / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D016487:Parenting / Q000523:psychology*; D010290:Parents / Q000523:psychology; D011599:Psychopathology; D012306:Risk; D012920:Social Behavior Disorders / Q000453:epidemiology*; D012931:Social Environment; D014430:Twins, Monozygotic / Q000523:psychology* / Q000706:statistics & numerical data
Differential parenting; MZ twin differences; Non-shared environment; Psychopathology