Current Pharmaceutical Design - Volume 18, Issue 32, 2012

Although cannabis use disorder is strongly related to schizophrenia and treatment of patients with double diagnosis provides serious problem, specific pharmacological, molecular and therapeutical data on this subgroup are poorly available. In this paper we present a critical review on psychopharmacological boundaries of schizophrenia with concurrent cannabis use. The relevant data available in the literature suggest Read More

Cannabis use and the development of schizophrenic psychoses share a variety of similarities. Both start during late adolescence; go along with neuropsychological deficits, reduced activity, motivation deficits, and hallucinations suggesting impairment of similar brain structures. In cannabis heavy users diminished regional gray and white matter volume was reported. Similar alterations were observed in the large literature a Read More

Cannabis is widely used recreationally and for symptomatic relief in a number of ailments. However, cannabis has been implicated as a risk factor for the development of psychotic illness. For forty years researchers have utilised intravenous preparations of Δ9- THC, as well as several other phytocannabinoids, in a laboratory setting. The intravenous route has the most reliable pharmacokinetics, reducing inter-individual varia Read More

The survival of any organism, animal or human, relies on the ability to accurately process, sense or tell time. Emerging evidence shows that timing is a crucial element in most, if not all, cognitive functioning and motor behaviour. Advances made by timing researchers provide valuable information on the neural substrates of interval timing, which indicate the involvement of certain brain areas and networks, most of whi Read More

There is growing and converging evidence that cannabis may be a major risk factor in people with psychotic disorders and prodromal psychotic symptoms. The lack of available pharmacological treatments for cannabis use indicates that psychological interventions should be a high priority, especially among people with psychotic disorders. However, there have been few randomised controlled trials (RCTs) of psychological int Read More

It is widely accepted that there is a close relationship between cannabis use, the endocannabinoid system, and psychosis. In particular, cannabis use has the potential to trigger the onset of psychosis in vulnerable individuals and to exacerbate psychotic symptomatology in schizophrenia patients, including positive, negative, and cognitive symptoms. With regard to the cognitive dysfunctions as a core feature of schizophre Read More

The rate of substance use, particularly cannabis, among patients with psychosis is high and much greater than in the general population. Persistent cannabis use by patients with an established psychotic disorder adversely affects prognosis and recovery. Little agreement has been reached on the reasons that sustain cannabis use in patients with psychosis although self-report studies have shown that patients appear to use can Read More

Objectives: Clinical and neurobiological findings suggest that cannabinoids and their receptors are implicated in schizophrenia. Cannabidiol (CBD), a non-psychotomimetic compound of the Cannabis sativa plant, has been reported to have central therapeutic actions, such as antipsychotic and anxiolytic effects. We have recently reported that spontaneously hypertensive rats (SHR) present a deficit in contextual fear conditioning Read More

Rationale: Animal and humans studies suggest that the two main constituents of cannabis sativa, delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) have quite different acute effects. However, to date the two compounds have largely been studied separately. Objective: To evaluate and compare the acute pharmacological effects of both THC and CBD in the same human volunteers. Methods: A randomised, Read More

Cannabis derivatives produce their CNS effect through activation of the endocannabinoid system, a recently discovered signalling system comprising specific receptors, their intrinsic lipid ligands and the associated enzymatic machinery (transporters, biosynthetic and degradative enzymes). This review provides the latest preclinical and clinical breakthroughs on the endocannabinoid system's role in psychotic disord Read More

Cannabis is among the most widely used illicit substances. Epidemiological and neuroscientific evidence, though poorly integrated, have established a strong association between cannabis use and increased risk of psychosis. Chronic cannabis use, especially of new synthetic varieties, may trigger psychosis and precipitate schizophrenia in vulnerable individuals. However, the specific pathways by which cannabis affects brain functio Read More

Cannabis is the most prevalent illicit substance used among schizophrenia patients. The effects of cannabis are mediated through the endocannabinoid system, which is a major regulator of neurotransmission and may be disturbed in schizophrenia. Though cognitive impairment in schizophrenia is well established, the effects of cannabis on cognition in schizophrenia patients are still unclear. This paper reviews 19 st Read More

Cannabis use is associated with a spectrum of effects including euphoria, relaxation, anxiety, perceptual alterations, paranoia, and impairments in attention and memory. Cannabis is made up of approximately 80 different cannabinoid compounds, which have synergistic or antagonistic effects on the principle active ingredient in cannabis, delta-9-tetrahydrocannabinol (THC). The net overall effect of cannabis is thought to be rel Read More

Cannabis use is associated with an increased risk for psychotic disorder, yet most cannabis users do not develop psychosis, suggesting that other factors are also involved. This paper reviews the available evidence suggesting that differential sensitivity to the psychosis-inducing effects of cannabis may be related to underlying genetic liability. There is robust evidence that persons at psychometric risk for psychosis are mos Read More

Cannabis use may be considered as an additional risk factor in a diathesis-stress model of schizophrenia where the risk of developing the illness would be higher in genetic vulnerable people. In this regard, much of the research on cannabis and psychosis is currently focusing on gene-environment interactions. The present review will focus on the interaction between genes and cannabis exposure in the development of Read More

Background: The relation between cannabis use and psychotic disorders has been investigated extensively. A series of metaanalytic reviews reveal a robust association between cannabis use and the development of psychosis and schizophrenia. However, the actual impact of cannabis use in subjects at high clinical risk for psychosis (CHR) is still unclear. Method: We conducted a systematic review of publications measuring the Read More

Pharmacological challenge in conjunction with neuroimaging techniques has been employed for over two decades now to understand the neural basis of the cognitive, emotional and symptomatic effects of the main ingredients of cannabis, the most widely used illicit drug in the world. This selective critical review focuses on the human neuroimaging studies investigating the effects of delta-9- tetrahydrocannabinol (THC) and Read More

A recent meta-analysis showed that the mean age of onset of psychosis among cannabis users was almost three years earlier than that of non-cannabis users. However, because cannabis users usually smoke tobacco, the use of tobacco might independently contribute to the earlier onset of psychosis. We aimed to use meta-analysis to compare the extent to which cannabis and tobacco use are each associated with an earlier Read More

It is unclear yet whether cannabis use is a moderating or causal factor contributing to grey matter alterations in schizophrenia and the development of psychotic symptoms. We therefore systematically reviewed structural brain imaging and post mortem studies addressing the effects of cannabis use on brain structure in psychosis. Studies with schizophrenia (SCZ) and first episode psychosis (FEP) patients as wel Read More

We conducted a systematic review on resting state cerebral blood flow activities found in first-episode psychosis (FEP) and during acute effects of cannabinoids and opioids, mental states that can be profoundly different from normal functioning. The main goal was to identify connections of cerebral blood flow measure and regional brain activity patterns associated with subjective experiences and to find out whether there ar Read More

Background:Duration of untreated psychosis (DUP) is an important predictor of outcome in first-episode psychosis (FEP). Cannabis use is highly prevalent in FEP patients and it is important to evaluate the potential impact of cannabis use on DUP. Methods: A systematic review of the literature was conducted to identify articles reporting DUP in FEP cannabis users (CU+) and nonusers (CU-) respectively. Studies meeting inclusion Read More

Over the past years a growing research effort has investigated the relation between cannabis use and schizophrenia at a neurobiological, epidemiological and clinical level. A number of systematic reviews and meta analyses have summarized the available evidence in the field. Conversely the patient's perception of the link between cannabis use and psychosis has been under investigation. Since patient's beliefs Read More

The link between cannabis and psychosis has often been debated with polarized views on the topic. There is substantial epidemiological evidence showing that cannabis increases the risk of psychosis, whereas other research suggests that schizophrenia patients self-medicate with the substance. These conflicting accounts may at least be partially explained by the two phytocannabinoids cannabidiol (CBD) and Δ 9-tetra Read More

Δ 9-tetrahydrocannabinol (Δ 9-THC) is the main compound of the Cannabis Sativa responsible for most of the effects of the plant. Another major constituent is cannabidiol (CBD), formerly regarded to be devoid of pharmacological activity. However, laboratory rodents and human studies have shown that this cannabinoid is able to prevent psychotic-like symptoms induced by high doses of Δ 9- THC. Subsequent studies have de Read More

Several lines of experimental and clinical evidence point to a close relationship between cannabis, the endogenous cannabinoid system, and schizophrenia. A variety of animal and human studies found a dysregulation of endocannabinoid signalling in psychosis. Elevated anandamide levels in schizophrenia patients that are negatively correlated with psychotic symptomatology indicate a protective role, whereas 2-arachidono Read More

Background: Although neurological soft signs (NSSs) have been consistently associated with schizophrenia and a variety of risk factors, few studies have focused on the association between NSSs and environmental factors such as cannabis use, particularly in patients with first episode psychosis (FEP). Aims: To review studies that have specifically investigated the association between NSSs and cannabis use in subjects who suffer f Read More

Objectives: This paper aimed to critically review the current literature concerning the possible association between cannabis use and suicidal behavior in patients with psychosis and in non-psychotic samples. Methods: We performed a detailed Pubmed/Medline, Scopus, PsycLit, and PsycInfo search to identify all papers and book chapters focusing on the association between cannabis use, and suicidal behavior during Read More

There is epidemiological evidence that frequent cannabis use in general and during puberty in particular increases the risk to suffer psychosis and psychotic symptoms. Based on these observations, there is growing interest in the role of the endogenous cannabinoid system (eCB system) - the point of action for psychoactive cannabinoids - in psychiatric disorders and schizophrenia in particular. It has been hypothesized nearly t Read More