Urbanicity, persecutory delusions, and clinical intervention: the development of a brief CBT module for helping patients with persecutory delusions enter social urban environments.

BACKGROUND: Substantial epidemiological research has shown that psychotic experiences are more common in densely populated areas. Many patients with persecutory delusions find it difficult to enter busy social urban settings. The stress and anxiety caused by being outside lead many patients to remain in-doors. We therefore developed a brief CBT intervention, based upon a formulation of the way urban environments cause stress and anxiety, to help patients with paranoid thoughts to feel less distressed when outside in busy streets. AIMS: The aim was to pilot the new intervention for feasibility and acceptability and gather preliminary outcome data. METHOD: Fifteen patients with persecutory delusions in the context of a schizophrenia diagnosis took part. All patients first went outside to test their reactions, received the intervention, and then went outside again. RESULTS: The intervention was considered useful by the patients. There was evidence that going outside after the intervention led to less paranoid responses than the initial exposure, but this was only statistically significant for levels of distress. CONCLUSIONS: Initial evidence was obtained that a brief CBT module specifically focused on helping patients with paranoia go outside is feasible, acceptable, and may have clinical benefits. However, it could not be determined from this small feasibility study that any observed improvements were due to the CBT intervention. Challenges in this area and future work required are outlined.

Binaural sluggishness precludes temporal pitch processing based on envelope cues in conditions of binaural unmasking.

Binaural sluggishness refers to the binaural system's inability to follow fast changes in the interaural configuration of the incoming sound stream. Several studies have measured binaural sluggishness by measuring signal detection in conditions of binaural unmasking when the interaural configuration of the masker is changed over time. However, it has been shown that, in conditions of binaural unmasking, binaural sluggishness also affects the perception of temporal changes in the properties of the signal (i.e., its frequency or level) and not just in the interaural configuration of the masker. By measuring the temporal modulation transfer function for sinusoidally modulated noise presented in conditions of binaural unmasking, the first experiment of the current study showed that, due to binaural sluggishness, the internal representation of binaurally unmasked sounds conveys little or no information about envelope fluctuations with rates within the pitch range (i.e., above 30 Hz). The second experiment measured the masked detection threshold for musical interval recognition in binaurally unmasked harmonic tones and showed that, in conditions of binaural unmasking, pitch wanes when the harmonics become unresolved by the cochlear filters. These results suggest that binaural sluggishness precludes temporal pitch processing based on envelope cues in binaurally unmasked sounds.

Central overexpression of angiotensin AT(1A) receptors prevents dopamine D(2) receptor regulation of alcohol consumption in mice.

BACKGROUND: While angiotensin receptors are found on the soma and terminals of dopaminergic neurons, controversy surrounds the potential role of angiotensin in alcohol consumption. METHODS: Using a transgenic mouse with a brain-specific overexpression of angiotensin AT(1A) receptors (NSE-AT(1A) mice), we have examined the role of angiotensin in alcohol consumption and alcohol-induced regulation of the dopaminergic system. RESULTS: The functional relevance of the overexpressed AT(1A) receptors was confirmed by an exaggerated rehydration response following 24-hour dehydration. NSE-AT(1A) mice showed a high preference for alcohol (similar to wild-type mice); yet, raclopride treatment had no effect on alcohol consumption in NSE-AT(1A) mice, while significantly reducing consumption in wild-type mice. In contrast, NSE-AT(1A) mice showed enhanced sensitivity to raclopride compared with wild types in terms of D(2) receptor up-regulation within the ventral mesencephalon. In addition, striatal D(2) receptors in NSE-AT(1A) mice were sensitive to up-regulation by chronic alcohol consumption. CONCLUSIONS: Collectively, these data imply that while expression of angiotensin AT(1A) receptors on striatal neurons has no impact upon basal alcohol consumption or preference, AT(1A) receptors do modulate the sensitivity of dopamine D(2) receptors to regulation by alcohol and the ability of a D(2) receptor antagonist to reduce consumption.

Misunderstanding the intentions of others: an exploratory study of the cognitive etiology of persecutory delusions in very late-onset schizophrenia-like psychosis.

OBJECTIVE: The objective of this study was to explore the cognitive etiology of persecutory delusion formation and maintenance in very late-onset schizophrenia-like psychosis (SLP). METHOD: Probabilistic reasoning, causal attributional style, and mentalizing ability were examined in 29 patients with SLP, 30 with onset of depression after the age of 60 years and 30 healthy comparison subjects. RESULTS: Patients with SLP made significantly more errors than the healthy comparison group in deception, but not false belief, mentalizing tasks. There were no significant performance differences between groups on the probabilistic reasoning task or the attributional style task. CONCLUSIONS: Mentalizing errors may contribute to the development and maintenance of persecutory delusions in SLP. These patients do not appear to show the wider range of cognitive biases described in deluded patients with schizophrenia with onset in younger adult life.