Psychedelic drugs are a focus of interest in the treatment of depression and other disorders but there are longstanding concerns about possible adverse psychiatric consequences. Because the relevant literature is largely informal, the seriousness of these risks is difficult to evaluate. Searches were made for case reports of schizophrenia-spectrum, affective or other psychiatric disorders after...
Introduction Research data show the impact of the endocannabinoid system on psychosis through its neurotransmission homeostatic functions. However, the effect of the endocannabinoid system genetic variability on the relationship between cannabis use and psychosis has been unexplored, even less in first-episode patients. Here, through a case-only design, we investigated the effect of cannabis...
The role of both cannabis use and genetic background has been shown in the risk for psychosis. However, the effect of the interplay between cannabis and variability at the endocannabinoid receptor genes on the neurobiological underpinnings of psychosis remains inconclusive. Through a case-only design, including patients with a first-episode of psychosis (n = 40) classified as cannabis users...
1. Objectives: While endocannabinoid system seems to be involved in processes underlying psychosis, research about Cannabinoid Receptor 2 gene (CNR2) is scarce and inconclusive. Some few reports indicate that CNR2 plays a role in psychiatric conditions, including depression or drug addiction (Onaivi et al., 2009). We aimed to evaluate the role of CNR2 and its interplay with cannabis on...
Objectives. To evaluate the association of cannabis use, genes of the endocannabinoid system and their interaction on clinical symptoms and cognitive performance in patients with a first-episode of pyschosis. Background. The role of both cannabis use and individual genetic background has been shown in the risk for psychosis. However, the influence of cannabis and variability at endocannabinoid...
It is not known whether first-episode psychosis is characterized by the same prefrontal cortex functional imaging abnormalities as chronic schizophrenia. Thirty patients with a first episode of non-affective functional psychosis and 28 healthy controls underwent functional magnetic resonance imaging (fMRI) during performance of the n-back working memory task. Voxel-based analyses of brain...
Background: Functional imaging studies using working memory tasks have documented both prefrontal cortex (PFC) hypo- and hyperactivation in schizophrenia. However, these studies have often failed to consider the potential role of task-related deactivation. Method: Thirty-two patients with chronic schizophrenia and 32 age- and sex-matched normal controls underwent functional magnetic resonance...
Background: The psychosis-inducing effect of ketamine is important evidence supporting the glutamate hypothesis of schizophrenia. However, the symptoms the drug produces have not been described systematically. Aim: To examine the effects of ketamine in healthy people using a structured psychiatric interview. Method: Ketamine (200 ng/ml) or placebo was administered by continuous infusion to 15...