The effects of paranoia and dopamine on perception of cohesion and conspiracy: a pre-registered, double-blind, placebo-controlled experiment.

Paranoia is a common symptom of psychotic disorders but is also present on a spectrum of severity in the general population. Although paranoia is associated with an increased tendency to perceive cohesion and conspiracy within groups, the mechanistic basis of this variation remains unclear. One potential avenue involves the brain's dopaminergic system, which is known to be altered in psychosis. In this study, we used large-N online samples to establish the association between trait paranoia and perceptions of cohesion and conspiracy. We further evaluated the role of dopamine on perceptions of cohesion and conspiracy using a double-blind, placebo-controlled laboratory experiment where participants received levodopa or a placebo control. Our results were mixed: group perceptions and perceptions of cohesion were higher among more paranoid individuals but were not altered under dopamine administration. We outline the potential reasons for these discrepancies and the broader implications for understanding paranoia in terms of dopamine dysregulation.

Can typical and atypical antipsychotics show differential effectiveness in treating paranoia and hallucinations in schizophrenia?

A dopamine excess is thought to be involved in positive psychotic symptoms in schizophrenia. All current antipsychotics show a degree of dopamine receptor antagonism. Little is known about the differential effectiveness of different antipsychotics in treating specific sets of symptoms. We report the case of a 35-year-old man with schizophrenia who presented with prominent hallucinatory symptoms (Positive and Negative Syndrome Scale [PANSS] P1=5, P3=5, P6=5) resistant to high doses of a dopamine, serotonin receptor antagonist, olanzapine. Switching from olanzapine to zuclopenthixol, a dopamine D2 receptor antagonist, led to a complete shift of his symptomatology: his hallucinations abated, however, he presented as very highly paranoid (PANSS P1=6, P3=2, P6=7). On a combination of both antipsychotics, his symptoms subsided (PANSS P1=3, P3=2, P6=2). We discuss the potential for differential effectiveness of different antipsychotic medications in treating hallucinations and paranoia. We argue that future studies could address this question by stratifying patients based on symptoms.

[Diagnosis and treatment of paranoid and schizophrenia-like psychosis in elderly patients].

Research supports theories on valid differences between early-onset schizophrenia (EOS), which persists through life, versus late-onset schizophrenia. We differentiate between schizophrenia, late-onset schizophrenia (LOS), very late-onset schizophrenia-like psychosis (VLOSLP) and paranoid psychosis in the elderly. While LOS may resemble EOS, VLOSLP may resemble neurodegenerative disorders such as Parkinson's disease and Alzheimer's disease. In this review, a treatment guideline is proposed.

Anti-AMPA receptor encephalitis associated with Medullary thyroid cancer.

AMPA receptor (AMPAR) antibodies are a group of recently discovered antibodies which target the neuronal synaptic proteins causing B-cell (immune) mediated neuronal damage, resulting in various neurologic syndromes depending on the area of central nervous system involvement. These syndromes are mostly reversible if treated early. Tumour association has been reported in up to 60% of cases in the most recent case series with lung, breast, ovarian cancers and thymomas being the most commonly associated malignancies with these antibodies. We present here the first case of AMPAR encephalitis associated with medullary thyroid cancer. Our patient presented with cognitive dysfunction and behavioural changes over a period of 3 weeks, with a full recovery after starting immunotherapy, once the diagnosis of AMPAR limbic encephalitis was established. This case highlights the importance of early diagnosis and management of AMPAR encephalitis as these patients respond well to immunotherapy and can have an almost complete recovery.

[Hypochondrical paranoia].

This is a case report of hypochondrical paranoia in a young man, who was convinced of a toxic infection by fungi following mold growth exposure. The patient was admitted to a psychiatric facility, severely pained by the delusional perception of his insides being eaten by fungus. He had undergone a thorough medical examination without the discovery of any somatic irregularities and had attempted to treat himself several times. After four months of hospital-ization and the prescription of antipsychotic treatment, he was in recovery. Mild delusions persisted but were no longer pathologically painful.

The effects of cannabidiol on persecutory ideation and anxiety in a high trait paranoid group.

BACKGROUND: Previous studies have suggested that cannabidiol has anxiolytic and antipsychotic properties, raising hopes that cannabidiol will translate to the psychiatric clinic. Cannabidiol may be particularly useful for anxiety and paranoia in those at-risk of major mental illness. METHODS: Immersion in a controlled 3D virtual-reality scenario was used to assay persecutory ideation and anxiety in a sample of non-clinical volunteers ( n=32) pre-selected for high paranoid traits. Participants were randomised to receive oral cannabidiol (600 mg) or placebo 130 min prior to entering virtual-reality. Well-validated rating scales were used to assay persecutory thinking and anxiety. Salivary cortisol concentration, heart rate and blood pressure were measured over the course of the experimental session. RESULTS: Immersion in the virtual-reality session elicited anxiety as indexed by the Beck's anxiety inventory ( p<0.005), and increased cortisol concentration ( p=0.05), heart rate ( p<0.05) and systolic blood pressure ( p<0.05). However, cannabidiol had no impact upon any of these effects, except for a strong trend to increase anxiety ( p=0.09). Cannabidiol had no effect on persecutory ideation as assayed by the Community Assessment of Psychic Experiences questionnaire or the State Social Paranoia Scale. CONCLUSIONS: In contrast to previous studies, there was no evidence of any benefits of cannabidiol on anxiety or persecutory ideation in healthy volunteers with high trait paranoia. However, a larger sample will be required for a definitive study.

Intact implicit processing of facial threat cues in schizophrenia.

An emerging body of research suggests that people with schizophrenia retain the ability to implicitly perceive facial affect, despite well-documented difficulty explicitly identifying emotional expressions. It remains unclear, however, whether such functional implicit processing extends beyond emotion to other socially relevant facial cues. Here, we constructed two novel versions of the Affect Misattribution Procedure, a paradigm in which affective responses to primes are projected onto neutral targets. The first version included three face primes previously validated to elicit varying inferences of threat from healthy individuals via emotion-independent structural modification (e.g., nose and eye size). The second version included the threat-relevant emotional primes of angry, neutral, and happy faces. Data from 126 participants with schizophrenia and 84 healthy controls revealed that although performing more poorly on an assessment of explicit emotion recognition, patients showed normative implicit threat processing for both non-emotional and emotional facial cues. Collectively, these results support recent hypotheses postulating that the initial perception of salient facial information remains intact in schizophrenia, but that deficits arise at subsequent stages of contextual integration and appraisal. Such a breakdown in the stream of face processing has important implications for mechanistic models of social cognitive impairment in schizophrenia and treatment strategies aiming to improve functional outcome.

Infection control for MRSA in a psychiatric hospital.

OBJECTIVE: This article examines the challenges in treating methicillin resistant Staphlococcus Aureus (MRSA) in an acute psychiatric inpatient unit. METHOD: The article outlines a case study of one particularly difficult patient who presented to an acute psychiatric hospital with a large wound that was MRSA positive and reviews the dilemmas facing mental health providers. RESULTS: The outcome of the case presented suggests that hospital policies interfered with the psychiatric treatment and recovery of an acutely ill patient as well as create possibly unnecessary costs. CONCLUSIONS: Hospitals should review their infection control policies to curb the spread of infection among patients and staff in an acute psychiatric setting.

Neuromyelitis optica, psychiatric symptoms and primary polydipsia: a case report.

Neuromyelitis optica (NMO) is an aggressive demyelinating disease that typically affects the optic nerves and spinal cord. While it is increasingly recognized that cerebral lesions are common in NMO, there have been no reported cases of NMO presenting with psychiatric symptoms and polydipsia. We describe a patient with classic signs and symptoms of NMO who also demonstrated prominent psychiatric symptoms and polydipsia that were tied to his flares and resolved with treatment of his NMO. This case expands our understanding of possible presentations of NMO.