Clinically significant but impractical? A response to Hageman and Arrindell

Hageman, and Arrindell [Hageman, W.J., & Arrindell, W.A. (in press). Establishing clinically significant change: increment of precision and the distinction between individual and group level of analysis. Behavior Research and Therapy.] suggest adaptations to the traditional clinical significance model originally developed by Jacobson, Follette, and Revenstorf [Jacobson, N.S., Follette, W.C., & Revenstorf, D. (1984). Toward a standard definition of clinically significant change. Behavior Therapy, 17, 308-311.]. They observe that one must distinguish between analysis at the individual and group level and based upon an alternative decision-making strategy have formulated different procedures for assessing clinically significant change that incorporate the unreliability inherent in testing measures. A comparison of the traditional method with Hageman and Arrindell's suggested approach is conducted utilizing data originally presented by Jacobson and Truax [Jacobson, N.S., & Truax, P., Clinical significance: a statistical approach to defining meaningful change in psychotherapy research. Journal of Consulting and Clinical Psychology, 59, 12-19.] and implications of this comparison for the method developed by Hageman and Arrindell's method are discussed. Although this revised method has much to recommend it, it seems to yield results at the individual level that are quite similar to those derived from the traditional method. Given the complexity of the revised method, the traditional model developed by Jacobson, Follette, and Revenstorf (1984) still seems to be preferable.     

Immobilization Stress Elevates GTP Cyclohydrolase I mRNA Levels in Rat Adrenals Predominantly by Hormonally Mediated Mechanisms

GTP cyclohydrolase I (GTPCH) is the rate-limiting enzyme in the biosynthesis of tetrahydrobiopterin, the cofactor for catecholamine, indolamine and nitric oxide biosynthesis. In this study we examined the effect of immobilization stress on GTPCH mRNA levels and the mechanism(s) of stress-induced changes in adrenomedullary GTPCH mRNA levels. We used reverse-polymerase chain reaction to isolate and clone a cDNA corresponding to nucleotides 269 to 570 of rat GTPCH. Northern blot analysis with a cRNA probe revealed two species of GTPCH mRNA (about 3.6 and 1.2 kb) in rat adrenal medulla and cortex, and in PC12 cells. The levels of both forms of GTPCH mRNA were significantly increased 3-5 fold in adrenal medulla by a single 2 hour immobilization and by repeated immobilizations (2 hours a day for 2 days). Hypophysectomy had little effect on their basal levels but prevented the stress elicited rise in both GTPCH mRNAs. In contrast, unilateral transection of the splanchnic nerve did not affect induction of the 3.6 kb GTPCH mRNA by stress. Combined denervation with hypophysectomy completely blocked the induction of both GTPCH mRNA species by immobilization stress. Thus, stress elicits elevation of both forms of GTPCH mRNA by a mechanism requiring an intact pituitary-adrenocortical axis.     

Examining a dimensional representation of depression and anxiety disorders' comorbidity in psychiatric outpatients with item response modeling

The current study replicated, in a sample of 2,300 outpatients seeking psychiatric treatment, a previous study (R. F. Krueger & M. S. Finger, 2001) that implemented an item response theory approach for modeling the comorbidity of common mood and anxiety disorders as indicators along the continuum of a shared latent factor (internalizing). The 5 disorders examined were major depressive disorder, social phobia, panic disorder/agoraphobia, specific phobia, and generalized anxiety disorder. The findings were consistent with the prior research. First, a confirmatory factor analysis yielded sufficient evidence for a nonspecific factor underlying the 5 diagnostic indicators. Second, a 2-parameter logistic item response model showed that the diagnoses were represented in the upper half of the internalizing continuum, and each was a strongly discriminating indicator of the factor. Third, the internalizing factor was significantly associated with 3 indexes of social burden: poorer social functioning, time missed from work, and lifetime hospitalizations. Rather than the categorical system of presumably discrete disorders presented in DSM-IV, these 5 mood and anxiety disorders may be alternatively viewed as higher end indicators of a common factor associated with social cost.     

The Role of Sleep Disturbance in Suicidal and Nonsuicidal Self‐Injurious Behavior among Adolescents

The relationship between different sleep disturbances and self‐harm thoughts and behaviors was examined among 223 adolescents presenting to a community clinic for mood disorders and suicidal and nonsuicidal self‐injurious behaviors. Two‐thirds of the adolescents reported nightly, severe sleep complaints. Relative to adolescents without significant sleep complaints, patients with severe sleep complaints at the time of clinic entry endorsed significantly more engagement in nonsuicidal self‐injury. Middle insomnia and circadian reversal were both significant predictors of suicide attempts. Terminal insomnia was significantly associated with suicidal ideation. Results support the importance of assessing sleep difficulties among adolescents at risk for suicide.