Background: Evidence suggests that depression and anxiety disorders are genetically based. Although symptoms of these internalizing disorders tend to correlate, the degree to which the related symptoms are heritable is unclear. This overlap has been conceptualized as Anxious Misery and existing research examining similar constructs of negative affect has revealed moderate heritability. However, it is unclear if some symptoms that characterize these constructs are more heritable than others. Modeling the symptom structure of Anxious Misery and examining which symptoms are most heritable may have implications for etiological models of internalizing disorders. Accordingly, the present study employed network analysis to explore the relationships across symptoms of Anxious Misery and to test if central symptoms in the network, compared to more peripheral symptoms, differ in their heritabilities.
Methods: Twin pairs (N = 1,344 pairs) with a mean age of 39 years (SD = 16 years) completed measures of anxiety and neuroticism to represent the Anxious Misery network.
Results: Panic-related symptoms were the most central in the network and were the most heritable, with genetic factors accounting for up to 59% of phenotypic variance. Peripheral symptoms were less heritable, accounting for as little as 21% of phenotypic variance. The degree of symptom heritability was strongly correlated with the degree of centrality of a symptom in the network (r = .53).
Limitations: Reliance on two self-report measures to represent Anxious Misery limits the generalizability of the findings.
Conclusions: Central and peripheral symptoms of an Anxious Misery network may differ in degree of heritability.
Olatunji BO, Christian C, Strachan E, Levinson CA. Central and Peripheral Symptoms in Network Analysis are Differentially Heritable A Twin Study of Anxious Misery. J Affect Disord. 2020 Sep 1;274:986-994.