Application to Anxiety Disorders

In an interesting extrapolation to psychopathol-ogy, McNaughton and Gray attribute GAD to excessive output from the SHS. Underscoring the information processing aspects of the SHS, they describe GAD as primarily a cognitive disorder that involves an excessive perception of threat and a subsequent suppression of approach and excessive avoidance of threat. In contrast, the fight flight system (which has a greater involvement of the amygdala fear system) mediates panic attacks (Gray, 1987, p....

Univariate Studies of Mood and Anxiety Disorder Symptoms

Kendler, Heath, Martin, & Eaves (1986) examined the causes of individual differences in anxiety and depressive symptoms in adults recruited from a large, nationwide twin registry in Australia. Symptoms of anxiety and depression were assessed by using a self-report questionnaire, the Delusions-Symptoms-States Inventory (DSSI). The authors found that a model including only genetic and nonshared environmental influences provided a satisfactory fit to the observed data, and the...

Schizophrenia Spectrum Disorders

As reviewed before, strong evidence exists that schizophrenia is a familial disorder and that genetic influences are involved in the clustering of schizophrenia in families. The liability to schizophrenia seems to be manifested in families not only through the occurrence of the classical disorder, but through other related phenotypes as well. That is, the predisposition to schizophrenia may be expressed in a number of different ways, including schizophrenia-like personality traits and cognitive...

Multivariate Behavior Genetic Studies of Childhood Disruptive Behavior Disorders

Numerous studies have documented a significant overlap between ADHD, ODD, and CD in both clinical and nonreferred samples. Biederman, Newcorn, and Sprich's 1991 review found that ADHD and CD co-occur in 30 to 50 of children and ADHD and ODD co-occur in a least 35 of children and that this result is consistent across both clinical and epidemiological samples. The considerable phenotypic overlap among these disorders suggests that the disorders share common etiological influences. Several...