Reliability and Validity of Clinical Diagnosis

As indicated, clinical diagnosis usually results in a specific categorization or label. After the patient has been appraised, the clinician offers a diagnosis (e.g., schizophrenia, paranoid type). If the diagnosis reflects a specific disease process that is known and understood, there is a reasonable probability that most diagnosticians might agree on the correct diagnosis. However, if the diagnostic category lacks preciseness and covers a moderate variety of behaviors, the reliability of the...

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...