Prognosis in medicine: An analysis of its meaning and rôles

The medical concept of prognosis is analysed into its basic constituents: patient data, medical intervention, outcome, utilities and probabilities; and sources of utility and probability values are discussed. Prognosis cannot be divorced from contemplated medical action, nor from action to be taken by the patient in response to prognostication. Regrettably, the usual decision-theoretic approach ignores this latter aspect. Elicitation of utilities, decision contemplation and prognostic counselling interweave, diagnostics playing a subsidiary role in decision-oriented clinical practice. At times the doctor has grounds for withholding information. As this is known to the patient, prognostic counselling becomes a conflict-prone and rationality-thwarting activity. The meaning of standard phrases such as “prognosis of a disease”, “the prognosis of this patient”, “the prognosis is unknown”, is examined.     

Fear conditioning in panic disorder: Enhanced resistance to extinction

Enhanced conditionability has been proposed as a crucial factor in the etiology and maintenance of panic disorder (PD). To test this assumption, the authors of the current study examined the acquisition and extinction of conditioned responses to aversive stimuli in PD. Thirty-nine PD patients and 33 healthy control participants took part in a differential aversive conditioning experiment. A highly annoying but not painful electrical stimulus served as the unconditioned stimulus (US), and two neutral pictures were used as either the paired conditioned stimulus (CS+) or the unpaired conditioned stimulus (CS-). Results indicate that PD patients do not show larger conditioned responses during acquisition than control participants. However, in contrast to control participants, PD patients exhibited larger skin conductance responses to CS+ stimuli during extinction and maintained a more negative evaluation of them, as indicated by valence ratings obtained several times throughout the experiment. This suggests that PD patients show enhanced conditionability with respect to extinction.     

Conclusions from shifts in morbidity patterns of hospitalized children with neuropsychiatric diseases

The decrease of neurological illnesses and the corresponding increase of psychogenic disturbances by patients belonging to clinical departments of neuropsychiatry of child and youth are described. This conversion leads to a frequently longer staying of the patients within the clinics. Furthermore, changes of the behaviours of the whole team for treatment may be observed.     

Nichtspezifische,funktionelle und somatoforme Körperbeschwerden

In the S3 guidelines on non-specific, functional and somatoform bodily complaints, a broad group of medical and psychological societies as well as patient representatives have for the first time achieved an evidence-based consensus on terminology and care of these patients. This paper summarizes the main background information and recommendations for psychotherapists. For mild courses treatment by the general practitioner with establishment of a biopsychosocial explanatory model and physical as well as social activation is usually sufficient. More severe courses call for cooperative, coordinated management, including regular appointments with the general practitioner, graded activation and psychotherapy, especially cognitive behavioral, in addition to psychodynamic interpersonal or hypnotherapeutic imaginative psychotherapy. In particularly severe courses multimodal and if necessary day clinic or inpatient treatment is needed. Additionally the patient guidelines for affected people and their relatives are presented.     

Trauma exposure is associated with increased context-dependent adjustments of cognitive control in patients with posttraumatic stress disorder and healthy controls

Recent evidence has suggested that posttraumatic stress disorder (PTSD) is associated with alterations in prefrontal-cortex-dependent cognitive processes (e.g., working memory, cognitive control). However, it remains unclear whether these cognitive dysfunctions are related to PTSD symptomatology or trauma exposure. Furthermore, regarding cognitive control, research has only focused on the integrity of selected control functions, but not their dynamic regulation in response to changing environmental demands. Therefore, the present study investigated dynamic variations in interference control, in addition to overall interference susceptibility and working memory (WM) performance in matched groups of 24 PTSD patients and 26 traumatized and 30 nontraumatized healthy controls. The Simon task was used to measure overall interference susceptibility and the flexible adjustment of cognitive control, on the basis of the occurrence of response conflicts (conflict adaptation effect). WM performance was assessed with the forward and backward digit span tasks. Since we have previously shown that trauma exposure per se is associated with reduced hair cortisol concentrations (HCC), we further explored whether PTSD/trauma-related cognitive alterations are related to HCC in proximal 3-cm hair segments. The results revealed that PTSD patients and traumatized controls showed significantly more pronounced conflict adaptation effects than nontraumatized controls. Moreover, the conflict adaptation effect was positively related to the number of lifetime traumatic events and the frequency of traumatization. The groups did not differ in overall interference susceptibility or WM performance. Exploratory analyses revealed no association between HCC and the observed cognitive differences. These results suggest that context-driven control adjustments constitute a sensitive correlate of trauma exposure, irrespective of PTSD.     

Deterministisches Chaos: Einige Wissenschaftstheoretisch Interessante Aspekte

Deterministic Chaos: Some Interesting Points of View from the Philosophy of Science. A comparatively simple example is used to present some of the main features of deterministic chaos. From the point of view of the philosophy of science, three questions are dealt with: if the equations of motion of chaotic systems are falsifiable in a strict sense; whether experiments on chaotic systems are reproducible; to what extent the development of chaotic systems is predictable. It emerges that in these respects chaotic systems, though being deterministic, behave essentially in the same way as stochastic (indeterministic) systems do.     

Testing unidimensionality in polytomous Rasch models

A fundamental assumption of most IRT models is that items measure the same unidimensional latent construct. For the polytomous Rasch model two ways of testing this assumption against specific multidimensional alternatives are discussed. One, a marginal approach assuming a multidimensional parametric latent variable distribution, and, two, a conditional approach with no distributional assumptions about the latent variable. The second approach generalizes the Martin-Löf test for the dichotomous Rasch model in two ways: to polytomous items and to a test against an alternative that may have more than two dimensions. A study on occupational health is used to motivate and illustrate the methods.The authors would like to thank Niels Keiding, Klaus Larsen and the anonymous reviewers for valuable comments to a previous version of this paper. This research was supported by a grant from the Danish Research Academy and by a general research grant from Quality Metric, Inc.