Advances in the psychosocial treatment of anxiety disorders. Implications for national health care.

Recent developments in the psychosocial treatments for anxiety disorders suggest that we have reached an early plateau. Evidence now exists on the effectiveness of psychosocial treatment approaches for every anxiety disorder when compared with no treatment or credible psychosocial placebos. In many cases these procedures have limited clinical effectiveness and much remains to be learned about the disseminability and clinical utility of these approaches in the context of emerging national health care plans. We are just beginning the first generation of multisite studies examining the potentially synergistic effects of proven psychosocial treatments and proven drug treatments. These studies that have substantial significance for national health care are reviewed and some preliminary results are reported.

Reliability of DSM-IV anxiety and mood disorders: implications for the classification of emotional disorders.

The reliability of current and lifetime Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV; American Psychiatric Association, 1994) anxiety and mood disorders was examined in 362 outpatients who underwent 2 independent administrations of the Anxiety Disorders Interview Schedule for DSM-IV: Lifetime version (ADIS-IV-L). Good to excellent reliability was obtained for the majority of DSM-IV categories. For many disorders, a common source of unreliability was disagreements on whether constituent symptoms were sufficient in number, severity, or duration to meet. DSM-IV diagnostic criteria. These analyses also highlighted potential boundary problems for some disorders (e.g., generalized anxiety disorder and major depressive disorder). Analyses of ADIS-IV-L clinical ratings (0-8 scales) indicated favorable interrater agreement for the dimensional features of DSM-IV anxiety and mood disorders. The findings are discussed in regard to their implications for the classification of emotional disorders.

Current and lifetime comorbidity of the DSM-IV anxiety and mood disorders in a large clinical sample.

The comorbidity of current and lifetime DSM-IV anxiety and mood disorders was examined in 1,127 outpatients who were assessed with the Anxiety Disorders Interview Schedule for DSM-IV: Lifetime version (ADIS-IV-L). The current and lifetime prevalence of additional Axis I disorders in principal anxiety and mood disorders was found to be 57% and 81%, respectively. The principal diagnostic categories associated with the highest comorbidity rates were mood disorders, posttraumatic stress disorder (PTSD), and generalized anxiety disorder (GAD). A high rate of lifetime comorbidity was found between the anxiety and mood disorders; the lifetime association with mood disorders was particularly strong for PTSD, GAD, obsessive-compulsive disorder, and social phobia. The findings are discussed in regard to their implications for the classification of emotional disorders.

How specific are specific phobias?

To study the generality of fears among specific phobic individuals and controls, 31 individuals with a DSM-IV diagnosis of specific phobia (natural environmental type: n = 13; blood-injection-injury type: n = 10; and situational type: n = 8) and 33 never mentally ill control subjects participated in an interview and questionnaire study. Based on subjects' fear ratings on the Fear Survey Schedule, subjects were classified as either positive or negative with regard to fear categories that correspond to the five diagnostic subtypes of specific phobia. Phobics showed overall a more generalized form of fear than controls. Furthermore, situational fears were more common among specific phobics who did not meet criteria for specific phobia, situational type, than among controls. These results add to the literature on the functional relationship among different fears and suggest that specific phobias are not as "specific" as is implied by the current diagnostic system.

Plant diversity and ecosystem productivity: theoretical considerations.

Ecosystem processes are thought to depend on both the number and identity of the species present in an ecosystem, but mathematical theory predicting this has been lacking. Here we present three simple models of interspecific competitive interactions in communities containing various numbers of randomly chosen species. All three models predict that, on average, productivity increases asymptotically with the original biodiversity of a community. The two models that address plant nutrient competition also predict that ecosystem nutrient retention increases with biodiversity and that the effects of biodiversity on productivity and nutrient retention increase with interspecific differences in resource requirements. All three models show that both species identity and biodiversity simultaneously influence ecosystem functioning, but their relative importance varies greatly among the models. This theory reinforces recent experimental results and shows that effects of biodiversity on ecosystem functioning are predicted by well-known ecological processes.