The being a patient effect: negative expectations based on group labeling and corresponding treatment affect patient performance

Patient studies provide insights into mechanisms underlying diseases and thus represent a cornerstone of clinical research. In this study, we report evidence that differences between patients and controls might partly be based on expectations generated by the patients’ knowledge of being invited and treated as a patient: the Being a Patient effect (BP effect). This finding extends previous neuropsychological reports on diagnosis threat. Participants with mild allergies were addressed either as patients or control subjects in a clinical study. We measured the impact of this group labeling and corresponding instructions on pain perception and cognitive performance. Our results provide evidence that the BP effect can indeed affect physiological and cognitive measures in clinical settings. Importantly, these effects can lead to systematic overestimation of genuine disease effects and should be taken into account when disease effects are investigated. Finally, we propose strategies to avoid or minimize this critical confound.     

Aggregate and individual replication probability within an explicit model of the research process

We study a model of the research process in which the true effect size, the replication jitter due to changes in experimental procedure, and the statistical error of effect size measurement are all normally distributed random variables. Within this model, we analyze the probability of successfully replicating an initial experimental result by obtaining either a statistically significant result in the same direction or any effect in that direction. We analyze both the probability of successfully replicating a particular experimental effect (i.e., the individual replication probability) and the average probability of successful replication across different studies within some research context (i.e., the aggregate replication probability), and we identify the conditions under which the latter can be approximated using the formulas of Killeen (2005a, 2007). We show how both of these probabilities depend on parameters of the research context that would rarely be known in practice. In addition, we show that the statistical uncertainty associated with the size of an initial observed effect would often prevent accurate estimation of the desired individual replication probability even if these research context parameters were known exactly. We conclude that accurate estimates of replication probability are generally unattainable.     

Psychodynamische Zusammenh?nge zwischen Psychose und Lebensgeschichte

Using two cases as examples it is shown how psychotic experiences and behaviour are psychodynamically associated with the biography of affected patients and can be beneficially used in therapy. Based on the historic pioneer work of Sigmund Freud who, with his psychoanalytical interpretation of Daniel Paul Schreber??s autobiography Memoirs of my nervous illness (Denkwürdigkeiten eines Nervenkranken) from 1903 shortly after his death 100 years ago, was the first to attempt to construct an association between Schreber??s delusional symptoms and his past history, this approach will be extensively discussed for patients with schizophrenia and similar psychoses. Particular attention is paid to trigger situations for the occurrence of psychotic conditions and the interpretation of certain delusional symptoms with respect to conflictual subjects from the past. In patients suffering from monopolar or bipolar affective disorders or psychoses, the symptoms are generally less exaggerated and extravagant than in schizophrenic psychoses. However, in such cases it can also be beneficial for the therapy in depressive or manic episodes to follow up the long-lasting conflicts which existed prior to the psychosis, where they either experience an escalation or describe an attempt to free themselves from previous pathogenic settings.