Dysfunctional attitudes and the serotonin transporter promoter polymorphism (5-HTTLPR)

Genetic Correlates of Maladaptive Beliefs: COMT VAL(158)MET and Irrational Cognitions Linked Depending on Distress

Maladaptive/irrational beliefs are significant cognitive vulnerability mechanisms in psychopathology. They are more likely to be associated with a genetic vulnerability marker under conditions of emotional distress when irrational beliefs are more salient. Therefore, in the current study we investigated the COMT Val(158)Met gene variation in relation to irrational beliefs, assuming this relationship depended on the level of emotional distress. Two hundred and sixty-seven genotyped volunteers were assessed for core/general maladaptive beliefs, as well as trait emotional distress. We focused on context-independent measures of irrational beliefs and emotional distress in the absence of a stressor. As expected, the relationship between COMT Val(158)Met and irrational beliefs depended on the level of emotional distress (f(2)=.314). The COMT Val(158)Met-irrationality association was significant only when individuals fell in the average to above average range of emotional distress. Furthermore, within this range the Met allele seemed to relate to higher irrational beliefs. These results were significant for overall irrational beliefs and its subtypes, but not for rational beliefs, the functional counterpart of irrationality. In light of the study's limitations, the results should be considered as preliminary. If replicable, these findings have potential implications for therapygenetics, changing the view that COMT Val(158)Met might be of greater relevance when treatment modality does not rely on cognitive variables.

Genetic and environmental etiologies of adolescent dysfunctional attitudes: a twin study

Despite the importance of dysfunctional attitudes in the development and maintenance of depression, little is known about the etiological origin of dysfunctional attitudes. The Dysfunctional Attitudes Scale for Children was administered to 674 adolescent twins derived from the Beijing Twin Study (BeTwiSt). Four hundred and thirty-nine monozygotic and 235 same-gender dizygotic twin pairs were included. Approximately 54% were females. The age range of the twins was 11-17 years. Model-fitting analyses were conducted. Biometric genetic model-fitting estimates indicated that additive genetic factors accounted for 31% (95% CI: 11%, 45%) of variance in adolescent dysfunctional attitude. The influence of shared environmental factors was small and negligible (9% [95% CI: 0%, 27%]). Non-shared environmental factors explained 60% (95% CI: 55%, 66%) of variance. Equating the estimate parameters across gender or age groups resulted in a non-significant difference of model fit, but there were trends suggesting higher heritability in females and older adolescents. Our results provide evidence for moderate heritability of dysfunctional attitudes in adolescents. Dysfunctional attitudes can be used as an endophenotype to identify risk genes for depression.

Therapygenetics: Using genetic markers to predict response to psychological treatment for mood and anxiety disorders

Considerable variation is evident in response to psychological therapies for mood and anxiety disorders. Genetic factors alongside environmental variables and gene-environment interactions are implicated in the etiology of these disorders and it is plausible that these same factors may also be important in predicting individual differences in response to psychological treatment. In this article, we review the evidence that genetic variation influences psychological treatment outcomes with a primary focus on mood and anxiety disorders. Unlike most past work, which has considered prediction of response to pharmacotherapy, this article reviews recent work in the field of therapygenetics, namely the role of genes in predicting psychological treatment response. As this is a field in its infancy, methodological recommendations are made and opportunities for future research are identified.

Toward an integration of cognitive and genetic models of risk for depression

There is growing interest in integrating cognitive and genetic models of depression risk. We review two ways in which these models can be meaningfully integrated. First, information-processing biases may represent intermediate phenotypes for specific genetic influences. These genetic influences may represent main effects on specific cognitive processes or may moderate the impact of environmental influences on information-processing biases. Second, cognitive and genetic influences may combine to increase reactivity to environmental stressors, increasing risk for depression in a gene×cognition×environment model of risk. There is now growing support for both of these ways of integrating cognitive and genetic models of depression risk. Specifically, there is support for genetic influences on information-processing biases, particularly the link between 5-HTTLPR and attentional biases, from both genetic association and gene×environment (G×E) studies. There is also initial support for gene×cognition×environment models of risk in which specific genetic influences contribute to increased reactivity to environmental influences. We review this research and discuss important areas of future research, particularly the need for larger samples that allow for a broader examination of genetic and epigenetic influences as well as the combined influence of variability across a number of genes.