The British Journal of Psychiatry
May 31, 2011
Maria Alice Fontes, Karen I Bolla, Paulo Jannuzzi Cunha et al.
300 citations
BACKGROUND: Many studies have suggested that adolescence is a period of particular vulnerability to neurocognitive effects associated with substance misuse. However, few large studies have measured differences in cognitive performance between chronic cannabis users who started in early adolescence (before age 15) with those who started later. AIMS: To examine the executive functioning of...
The British Journal of Psychiatry
October 2010
Celia J. A. Morgan, Gráinne Schäfer, Tom P. Freeman et al.
The two main constituents of cannabis, cannabidiol and Δ(9)-tetrahydrocannabinol (THC), have opposing effects both pharmacologically and behaviourally when administered in the laboratory. Street cannabis is known to contain varying levels of each cannabinoid. To study how the varying levels of cannabidiol and THC have an impact on the acute effects of the drug in naturalistic settings. Cannabis...
The British Journal of Psychiatry
September 30, 2010
Cécile Henquet, Rebecca Kuepper
16 citations
A recent study by Morgan and colleagues found that cannabidiol attenuates the acute cognitive effects of delta-9-tetrahydrocannabinol (THC). This is of interest as THC has been associated with the detrimental effects of cannabis on mental health in at-risk users, and the potency of cannabis is increasing across Europe.
The British Journal of Psychiatry
August 31, 2010
Ian Kelleher, Jack A. Jenner, Mary Cannon
82 citations
Our ideas about the intrinsically pathological nature of hallucinations and delusions are being challenged by findings from epidemiology, neuroimaging and clinical research. Population-based studies using both self-report and interview surveys show that the prevalence of psychotic symptoms is far greater than had been previously considered, prompting us to re-evaluate these psychotic symptoms...
The British Journal of Psychiatry
May 31, 2010
Cécile Henquet, Jim van Os, Rebecca Kuepper et al.
124 citations
BACKGROUND: Little is known about the experiential dynamics of the interaction between cannabis and vulnerability to psychosis. AIMS: To examine the effects of cannabis on psychotic symptoms and mood in patients with psychosis and healthy controls. METHOD: Patients with a psychotic disorder (n = 42) and healthy controls (n = 38) were followed in their daily lives using a structured...
The British Journal of Psychiatry
December 31, 2009
Agna A. Bartels‐Velthuis, Jack A. Jenner, G. van de Willige et al.
105 citations
BACKGROUND: Hearing voices occurs in middle childhood, but little is known about prevalence, aetiology and immediate consequences. AIMS: To investigate prevalence, developmental risk factors and behavioural correlates of auditory vocal hallucinations in 7- and 8-year-olds. METHOD: Auditory vocal hallucinations were assessed with the Auditory Vocal Hallucination Rating Scale in 3870 children....
The British Journal of Psychiatry
November 30, 2009
Marta Di Forti, Craig Morgan, Paola Dazzan et al.
577 citations
BACKGROUND: People who use cannabis have an increased risk of psychosis, an effect attributed to the active ingredient Delta 9-tetrahydrocannabinol (Delta 9-THC). There has recently been concern over an increase in the concentration of Delta 9-THC in the cannabis available in many countries. AIMS: To investigate whether people with a first episode of psychosis were particularly likely to use...
The British Journal of Psychiatry
March 31, 2009
Sudhakar Selvaraj, Rosa Hoshi, Zubin Bhagwagar et al.
59 citations
Background Animal experimental studies have prompted concerns that widespread use of 3,4-methylenedioxymethamphetamine (MDMA; ‘ecstasy’) by young people may pose a major public health problem in terms of persistent serotonin neurotoxicity. Aims To determine the status of brain serotonin neurons in a group of abstinent MDMA users. Method We assessed the integrity of brain serotonin neurons by...
The British Journal of Psychiatry
October 31, 2008
Stanley Zammit, Theresa HM Moore, Anne Lingford‐hughes et al.
275 citations
BACKGROUND: It is unclear if research findings support clinical opinion that cannabis use leads to worse outcomes in people with psychosis, or whether this impression is confounded by other factors. AIMS: To systematically review the evidence pertaining to whether cannabis affects outcome of psychotic disorders. METHOD: We searched 10 relevant databases (to November 2006), reference lists of...
The British Journal of Psychiatry
August 31, 2008
Jeremy P. Horwood, Giovanni E. Salvi, Kate Thomas et al.
277 citations
BACKGROUND: Non-clinical psychotic symptoms appear common in children, but it is possible that a proportion of reported symptoms result from misinterpretation. There is a well-established association between pre-morbid low IQ score and schizophrenia. Psychosis-like symptoms in children may also be a risk factor for psychotic disorder but their relationship with IQ is unclear. AIMS: To...
The British Journal of Psychiatry
August 1, 2006
Leanne M Hides, Sharon Dawe, David J. Kavanagh et al.
BackgroundCannabis use appears to exacerbate psychotic symptoms and increase risk of psychotic relapse. However, the relative contribution of cannabis use compared with other risk factors is unclear. The influence of psychotic symptoms on cannabis use has received little attention.AimsTo examine the influence of cannabis use on psychotic symptom relapse and the influence of psychotic symptom...
The British Journal of Psychiatry
August 1, 2006
Edith Pomarol‐Clotet, Garry D Honey, G K Murray et al.
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...
The British Journal of Psychiatry
February 1, 2006
Ursula Werneke, Trevor Turner, Stefan Priebe
98 citations
The use of complementary medicines in those with mental health problems is well documented. However, their effectiveness is often not established and they may be less harmless than commonly assumed. To review the complementary medicines routinely encountered in psychiatric practice, their effectiveness, potential adverse effects and interactions. Electronic and manual literature search on the...
The British Journal of Psychiatry
December 30, 2005
Danilo Arnone, Fabrizio Schifano
2 citations
It is likely therefore that cognitive impair-It is likely therefore that cognitive impairment was present in many.Hence the ment was present in many.Hence the 'personality subtypes' identified may vanish 'personality subtypes' identified may vanish on refeeding, or may be more pronounced, on refeeding, or may be more pronounced, having been masked by cognitive blunting.having been masked by...
The British Journal of Psychiatry
November 30, 2005
Mikkel Arendt, Raben Rosenberg, Leslie Foldager et al.
258 citations
BACKGROUND: Few studies have examined samples of people with cannabis-induced psychotic symptoms. AIMS: To establish whether cannabis-induced psychotic disorders are followed by development of persistent psychotic conditions, and the timing of their onset. METHOD: Data on patients treated for cannabis-induced psychotic symptoms between 1994 and 1999 were extracted from the Danish Psychiatric...
The British Journal of Psychiatry
November 1, 2005
V. Murray
2 citations
Crowley's in-depth understanding of the complexity in-depth understanding of the complexity and value of the altered state of and value of the altered state of consciousness.Thankfully, there are clini-consciousness.Thankfully, there are clinicians such as Dr Crowley with the con-cians such as Dr Crowley with the confidence not to dismiss the non-ordinary fidence not to dismiss the non-ordinary...
The British Journal of Psychiatry
November 1, 2005
B. Sessa
Grof (1975Grof ( , 1990) ) has been the most Grof (1975Grof ( , 1990) ) has been the most prominent explorer of these inaccessible prominent explorer of these inaccessible regions for over 40 years and once research regions for over 40 years and once research into lysergic acid diethylamide (LSD) into lysergic acid diethylamide (LSD) became impossible, developed a technique became impossible,...
The British Journal of Psychiatry
November 1, 2005
G. Edwards
Grof (1975Grof ( , 1990) ) has been the most Grof (1975Grof ( , 1990) ) has been the most prominent explorer of these inaccessible prominent explorer of these inaccessible regions for over 40 years and once research regions for over 40 years and once research into lysergic acid diethylamide (LSD) into lysergic acid diethylamide (LSD) became impossible, developed a technique became impossible,...
The British Journal of Psychiatry
June 1, 2005
Ben Sessa
97 citations
Psychedelic or hallucinogenic drugs such as lysergic acid diethylamide (LSD), 3, 4, 5-trimethoxy-β-phenethylamine (mescaline), psilocybin, 3, 4-methylenedioxymethamph-etamine (MDMA), N, N-dimethyltrypta-mine (DMT) and their relations occur in abundance throughout the natural world, and have been used by humankind for thousands of years.
The British Journal of Psychiatry
January 30, 2004
Louise Arseneault, Mary Cannon, John Witton et al.
924 citations
BACKGROUND: Controversy remains as to whether cannabis acts as a causal risk factor for schizophrenia or other functional psychotic illnesses. AIMS: To examine critically the evidence that cannabis causes psychosis using established criteria of causality. METHOD: We identified five studies that included a well-defined sample drawn from population-based registers or cohorts and used prospective...
The British Journal of Psychiatry
January 2002
J L Crammer
Confusional states associated with medical and surgical conditions require more study and biochemical explanation. To understand impairment of consciousness, cognition and memory. A psychiatrist reports experience of his changing mental state over 5 days from notes made immediately on recovery. A prodromal phase of declining consciousness, understanding and memory registration over perhaps 48 h...
The British Journal of Psychiatry
February 1, 2001
Andrew Johns
474 citations
BACKGROUND: Cannabis is commonly regarded as an innocuous drug and the prevalence of lifetime and regular use has increased in most developed countries. However, accumulative evidence highlights the risks of dependence and other adverse effects, particularly among people with pre-existing psychiatric disorders. AIMS: To re-evaluate the adverse effects of cannabis in the general population and...
The British Journal of Psychiatry
2000
Yair Bar-El, Rimona Durst, Grégory Katz et al.
63 citations
BACKGROUND: Jerusalem's psychiatrists expect to encounter, as the millennium approaches, an ever-increasing number of tourists who, upon arriving in Jerusalem, may suffer psychotic decompensation. AIMS: To describe the Jerusalem syndrome as a unique acute psychotic state. METHOD: This analysis is based on accumulated clinical experience and phenomenological data consisting of cultural and...
The British Journal of Psychiatry
July 1, 1999
David M. Semple, Klaus P. Ebmeier, Michael F. Glabus et al.
281 citations
Background The use of MDMA (‘ecstasy’) is common among young people in Western countries. Animal models of MDMA toxicity suggest a loss of serotonergic neurons, and potentially implicate it in the development of significant psychiatric morbidity in humans. Aims To test whether long-term use of MDMA can produce abnormalities in cerebral serotonin, but not dopamine, transporter binding measured...
The British Journal of Psychiatry
October 1, 1996
Maurice Ohayon, R G Priest, M Caulet et al.
Hypnagogic and hypnopompic hallucinations are common in narcolepsy. However, the prevalence of these phenomena in the general population is uncertain. A representative community sample of 4972 people in the UK, aged 15-100, was interviewed by telephone (79.6% of those contacted). Interviews were performed by lay interviewers using a computerised system that guided the interviewer through the...