Artemis Igoumenou

How Cannabis Causes Paranoia: Using the Intravenous Administration of ∆9-Tetrahydrocannabinol (THC) to Identify Key Cognitive Mechanisms Leading to Paranoia

Paranoia is receiving increasing attention in its own right, since it is a central experience of psychotic disorders and a marker of the health of a society. Paranoia is associated with use of the most commonly taken illicit drug, cannabis. The objective was to determine whether the principal psychoactive ingredient of cannabis—∆9-tetrahydrocannabinol (THC)—causes paranoia and to use the drug as a probe to identify key cognitive mechanisms underlying paranoia. A randomized, placebo-controlled, between-groups test of the effects of intravenous THC was conducted. A total of 121 individuals with paranoid ideation were randomized to receive placebo, THC, or THC preceded by a cognitive awareness condition. Paranoia was assessed extensively via a real social situation, an immersive virtual reality experiment, and standard self-report and interviewer measures. Putative causal factors were assessed. Principal components analysis was used to create a composite paranoia score and composite causal variables to be tested in a mediation analysis. THC significantly increased paranoia, negative affect (anxiety, worry, depression, negative thoughts about the self), and a range of anomalous experiences, and reduced working memory capacity. The increase in negative affect and in anomalous experiences fully accounted for the increase in paranoia. Working memory changes did not lead to paranoia. Making participants aware of the effects of THC had little impact. In this largest study of intravenous THC, it was definitively demonstrated that the drug triggers paranoid thoughts in vulnerable individuals. The most likely mechanism of action causing paranoia was the generation of negative affect and anomalous experiences.

Treatment of psychosis in prisons and violent recidivism

Background Violence among released prisoners with psychosis is an important public health problem. It is unclear whether treatment in prison can influence criminal behaviour subsequent to release. Aims To investigate whether treatment in prison can delay time to reoffending. Method Our sample consisted of 1717 adult prisoners in England and Wales convicted of a serious violent or sexual offence. We used Cox regression to investigate the effects of treatment received in prison on associations between mental illness and time to first reconviction following release. Results Prisoners with current symptoms of schizophrenia reoffended quicker following release. Nevertheless, treatment with medication significantly delayed time to violence (18% reduction). Treatment for substance dependence delayed violent and non-violent reoffending among prisoners with drug-induced psychosis. Conclusions Identifying prisoners with psychosis and administering treatment in prison have important protective effects against reoffending. Repeated screening with improved accuracy in identification is necessary to prevent cases being missed. Declaration of interest None. Copyright and usage

Geographic trends of scientific output and citation practices in psychiatry

BackgroundMeasures of research productivity are increasingly used to determine how research should be evaluated and funding decisions made. In psychiatry, citation patterns within and between countries are not known, and whether these differ by choice of citation metric.MethodIn this study, we examined publication characteristics and citation practices in articles published in 50 Web of Science indexed psychiatric and relevant clinical neurosciences journals, between January 2004 and December 2009 comprising 51,072 records that produced 375,962 citations. We compared citation patterns, including self-citations, between countries using standard x2 tests.ResultsWe found that most publications came from the USA, with Germany being second and UK third in productivity. USA articles received most citations and the highest citation rate with an average 11.5 citations per article. The UK received the second highest absolute number of citations, but came fourth by citation rate (9.7 citations/article), after the Netherlands (11.4 citations/article) and Canada (9.8 citations/article).Within the USA, Harvard University published most articles and these articles were the most cited, on average 20.0 citations per paper. In Europe, UK institutions published and were cited most often. The Institute of Psychiatry/Kings College London was the leading institution in terms of number of published records and overall citations, while Oxford University had the highest citation rate (18.5 citations/record).There were no differences between the self-citation practices of American and European researchers.Articles that examined some aspect of treatment in psychiatry were the most published. In terms of diagnosis, papers about schizophrenia-spectrum disorders were the most published and the most cited.ConclusionsWe found large differences between and within countries in terms of their research productivity in psychiatry and clinical neuroscience. In addition, the ranking of countries and institutions differed widely by whether productivity was assessed by total research records published, overall citations these received, or citations per paper. The choice of measures of scientific output could be important in determining how research output translates into decisions about resource allocation.

Psychiatric disorders and criminal history in male prisoners in Greece.

OBJECTIVES Τo explore the psychopathology of the Greek male prisoner population and the relationship between psychiatric disorders and the criminal history of the subjects. METHODS The Iowa Structured Psychiatric Interview and the Personality Disorders Questionnaire were administered. The prevalence of the most common mental disorders was analyzed separately and in relation to the criminal history. SPSS was used for the statistical analysis. RESULTS A total of 495 male prisoners were interviewed. Overall, 223 (45.06%) were diagnosed with a psychiatric disorder. Non-violent crimes were the most prevalent reason for imprisonment (40.7%). One-third (30.3%) of the sample was convicted with drug-related crimes, and 28.0% with violent crimes. DISCUSSION The prevalence of mental disorders in Greek prisoners was higher than in the general population. Personality disorder was the most common type of mental disorder and the only psychiatric diagnosis related to violent crime. This highlights the need for screening for mental disorders and the need for therapeutic provision within the prison setting.

Depression in patients with hypertrophic cardiomyopathy: is there any relation with the risk factors for sudden death?

Objectives The aim of this study was to investigate whether depressive symptoms are related to the risk factors for sudden death in patients with hypertrophic cardiomyopathy (HCM). Design 121 patients diagnosed as having HCM were assessed for depressive symptomatology using the Beck Depression Inventory and the Center for Epidemiological Studies Depression Scale (CES-D) and followed up for a period of 2 years. For the interview, the authors used the Structured Clinical Interview for DSM-III/DSM-III-R. A multidimensional longitudinal study was carried out with both somatic and psychological symptoms and signs taken into consideration. SPSS was used for the statistical analysis. Results (1) Patients with HCM are more depressed than the general population. (2) There is no positive correlation between the occurrence of depressive symptoms and the risk factors for sudden death in patients with HCM. (3) Patients at high risk for sudden death are not more depressed than the others. (4) Time from diagnosis of the cardiac disease is not related to the presence and severity of depressive symptoms. Conclusions Patients with HCM are more depressed than the general population. The authors suggest that depressive symptoms and risk factors for sudden death in these patients are not related. It is important to screen for mood disorders in this patient population in order to provide an early diagnosis and treatment of the psychiatric disease.

Personality disorder and violence in the national household population of Britain

Abstract Background: Antisocial personality disorder (ASPD) is strongly associated with violence but the effects of other personality disorder (PD) categories are uncertain. Purpose: To investigate associations between 10 DSM-IV PD categories and effects of co-occurring disorders on self-reported violence. Method: Cross-sectional survey of 8397 adults aged 16–74 years in households in Great Britain. Results: ASPD contributed strongly to the burden of violence in the British population. Paranoid and obsessive–compulsive PD made additional independent contributions, and narcissistic PD contributed to intimate partner violence. The prevalence of violence correlated with the number of PD categories. Comorbid alcohol dependence further increased the risk. Conclusions: Risk of violence increases with increasing severity of PD, measured by the number of PD categories, and with co-occurring alcohol dependence. Not all PD categories are associated with violence, and avoidant PD was protective. Identification of targets for future interventions may be obscured using a classification based solely on severity.