Cannabis affects the severity of schizophrenic symptoms: results of a clinical survey (original) (raw)
Related papers
Journal of Substance Use, 2018
Background: The literature on the effects of cannabis use by patients with schizophrenia is variable. Aims: To determine whether there are differences among urine-screened cannabis-only users, polysubstance users using cannabis, and nonusers on the number of inpatient hospitalizations and length of stay for patients with schizophrenia or schizoaffective disorder. Method: This study (N = 116) included patients who tested positive for only cannabis (n = 20, Group 1); tested positive for cannabis and had a history of other substance use (n = 43, Group 2); and had negative drug screens (n = 53, Group 3). Results: Groups 1 and 2 had significantly lower numbers of hospitalizations than Group 3 without controlling for any other factors, and non-significantly lower lengths of stay than Group 3. Conclusions: Our results do not support the hypothesis that cannabis exacerbates psychotic symptoms in patients with schizophrenia or schizoaffective disorder. Our study is unique in that it utilized objective urine drug screens.
Cannabis-Induced Psychotic-Like Experiences Are Predicted by High Schizotypy
Psychopathology, 2008
of cannabis use were not related to schizotypy. Exploratory factor analysis of the pooled data from this study and our previous report (providing a sample of 1 400 cannabis users) suggested a 3-factor solution. These were characterised as a psychotic-dysphoric index (factor 1), an expansive index (factor 2) and an intoxicated index (factor 3). Schizotypy was highly correlated with factors 1 and 3, though not with factor 2. Conclusion: High scoring schizotypes who use cannabis are more likely to experience psychotic-dysphoric phenomena and intoxicating effects during and after use. Our results confirm and expand the findings reported in our previous study. They are consistent with the hypothesis that cannabis use may be a risk factor for full psychosis in this group.
Cannabis-Induced Psychosis-Like Experiences Are Associated with High Schizotypy
Psychopathology, 2006
unpleasant after-effects associated with cannabis use. The pleasurable effects of cannabis use were not related to schizotypy score. Conclusion: High scoring schizotypes who use cannabis are more likely to experience psychotic-like phenomena at the time of use, and unpleasant after-effects. Our results are consistent with the hypothesis that cannabis use is a risk factor for full psychosis in this group.
Cannabis and schizophrenia: impact on onset, course, psychopathology and outcomes
European Archives of Psychiatry and Clinical Neuroscience, 2002
s Abstract Cannabis consuming schizophrenic patients are younger at onset, are likely to have started abuse before onset of schizophrenia and show more prominent positive symptoms than nonabusers. It has been suggested that cannabis is a risk-factor for schizophrenia. Our aim was to assess prevalence and pattern of cannabis use in 125 chronic male schizophrenic subjects and its impact on socioepidemiological and clinical variables as well as which disorder precedes the other in onset. Assessment of consumption was made with a semi-structured clinical interview. Clinical status was assessed by means of the SANS, SAPS, PANSS and BPRS scales. Cannabis consumption was found in 54 subjects (43 %), 66.7 % of whom started it at least three years before onset of schizophrenia. Consumers were younger and with lower negative symptoms, specially abusers and polysubstance abusers. Family history positive for psychosis was more frequent in consumers, especially when consumption started before onset of schizophrenia. Subjects whose onset of schizophrenia preceded the beginning of cannabis abuse had more positive symptoms than those who started abuse before the onset of schizophrenia. On these grounds, our sample could be subdivided into two main groups, one that uses substances to counter distressing symptoms of schizophrenia and another in which cannabis might be one of the factors predisposing to the disease; the former had less negative symptoms than nonabusers. Our data support both heterogeneity of schizophrenia and genetic susceptibility to environmental agents. s
Cannabis use and psychotic disorders: an update
Drug and Alcohol Review, 2004
This paper evaluates three hypotheses about the relationship between cannabis use and psychosis in the light of recent evidence from prospective epidemiological studies. These are that: (1) cannabis use causes a psychotic disorder that would not have occurred in the absence of cannabis use; (2) that cannabis use may precipitate schizophrenia or exacerbate its symptoms; and (3) that cannabis use may exacerbate the symptoms of psychosis. There is limited support for the first hypothesis. As a consequence of recent prospective studies, there is now stronger support for the second hypothesis. Four recent prospective studies in three countries have found relationships between the frequency with which cannabis had been used and the risk of receiving a diagnosis of schizophrenia or of reporting psychotic symptoms. These relationships are stronger in people with a history of psychotic symptoms and they have persisted after adjustment for potentially confounding variables. The absence of any change in the incidence of schizophrenia during the three decades in which cannabis use in Australia has increased makes it unlikely that cannabis use can produce psychoses that would not have occurred in its absence. It seems more likely that cannabis use can precipitate schizophrenia in vulnerable individuals. There is also reasonable evidence for the third hypothesis that cannabis use exacerbates psychosis. [Hall W, Degenhardt L, Teeson M. Cannabis use and psychotic disorders: an update.
Progress in Neuro-Psychopharmacology and Biological Psychiatry, 2011
Background: Although incidence of schizophrenia is higher among cannabis users and marijuana is the most common abused drug by adolescents, etiological linkage between schizophrenia and cannabis use is still not clarified. Clinical experiences suggest that regular cannabis user can show similar psychotic episode to schizophrenic disorders but it is still unclear if chronic cannabis use with schizophreniform disorder is a distinct entity requiring special therapy or it can be treated as classical schizophrenia. There are no data available on the comparison of pharmacotherapy between schizophreniform patients with and without cannabis use. Methods: Clinical data of 85 patients with schizophrenia spectrum disorder were analyzed retrospectively. Cannabis use was not reported by 43 persons (Cnbs0 subgroup) and 42 patients used regularly cannabis during at least 1 year (Cnbs1 subgroup). Comparison of anamnesis, family history, social-demographic condition, positive and negative symptoms, acute and long-term therapies recorded by clinical interviews was performed with chi square tests, logistic binary regression and t-tests using SPSS 13.0 for Windows software. Results: Men were over-represented in cannabis dependent group while mean age was lower among them compared to Cnbs0 subgroup. Prevalence of suicidal attempt was increased in men without cannabis use (OR = 5.25, p = 0.016). Patients without cannabis use spent more time in hospital (p = 0.026) and smoking was more frequent among them (OR = 1.36, p = 0.047). The chance to get olanzapine for acute therapy and aripiprazol for long term therapy was more than two fold in Cnbs1 subgroup (OR = 2.66, OR = 3.67, respectively). However, aripiprazol was used for acute therapy with significantly lower risk in Cnbs1 subgroup (OR = 0.47, p = 0.023). Olanzapine was administered for long term therapy in a higher dose to Cnbs0 patients (p = 0.040). Also higher dose of risperidon LAI was used in women without cannabis dependency compared to women of Cnbs1 subgroup (p = 0.020). Positive and negative symptoms and family history did not differ significantly between the two subgroups. Conclusion: Although symptom profile was similar, hospitalization time, suicidal anamnesis, smoking habit and also dosage, intensity and lasting of therapy were different between the two subgroups. Further prospective studies are required for the investigation of the clinical and molecular background of this discrepancy in order to determine a relevant protocol of prevention and treatment of the chronic cannabis use related psychotic disorder.
Cannabis-induced psychosis: a cross-sectional comparison with acute schizophrenia
SUMMARY Objective: The existence of cannabis-induced psychosis (CP) remains controversial, partly because of methodological problems. We hypothesize that acute schizophrenia (AS) and CP can have distinct demographic, premorbid, and clinical features. Method: We compared 26 patients with CP to 35 with AS, after their cannabis-consumption status was confirmed by repeated urine screens. Patients with CP were assessed after at least one week but not more than one month of abstinence. Symptoms were evaluated with the Present State Examination. Results: In group CP, male gender, expansive mood and ideation, derealisation/depersonalisation, visual hallucinations, and disturbances of sensorium were more frequent than in group AS. Premorbid schizoid personality traits were more frequently associated to AS and antisocial personality traits to CP. Conclusion: The continuous heavy use of cannabis can induce a psychotic disorder distinct from AS. These two clinical entities share some features but they differ in others. Key words: psychoses, substance-induced; cannabis abuse; schizophrenia
Determining factors for Cannabis use among Moroccans Schizophrenic Patients: A cross sectional study
Avicenna Journal of Phytomedicine, 2020
Objective: Cannabis use is considered a major clinical problem associated with a poorer outcome in patients with schizophrenia. The objective of the present study was to assess the prevalence of cannabis us among patients with schizophrenia. The assessment consists in comparing some factors related to substance use in a population of schizophrenic patients between cannabis users and non- Materials and Methods: Four hundred and three participants who were examined prospectively during their hospitalization answered the PANNS scale of schizophrenia, GAF, BIS-10, CDSS, and MARS. The consumption of cannabis was investigated using urine toxicological analysis. Sociodemographic, clinical and therapeutic data were also recorded. Results: The prevalence of cannabis use among schizophrenic inpatients was 49%. Patients with cannabis use were younger (31.7 vs 34.9 years old, p<0.001), more often male (52 vs 20% female, p<0.001), and they presented more often a history of imprisonment (68...
2011
Several studies have established a link between cannabis and psychosis. However the causal role of cannabis in schizophrenia is still not clear. The aim of this paper is to summarise the literature pertaining to whether cannabis causes psychosis, whether the continued use of cannabis by patients with schizophrenia affects the course of the disease and its treatment, and whether it is possible to reduce cannabis use in patients who have a psychotic disorder.
Marihuana and Medicine, 1999
Background Schizophrenia is a mental illness causing disordered beliefs, ideas and sensations. Many people with schizophrenia smoke cannabis, and it is unclear why a large proportion do so and if the effects are harmful or beneficial. It is also unclear what the best method is to allow people with schizophrenia to alter their cannabis intake. Objectives To assess the effects of specific psychological treatments for cannabis reduction in people with schizophrenia. To assess the effects of antipsychotics for cannabis reduction in people with schizophrenia. To assess the effects of cannabinoids (cannabis related chemical compounds derived from cannabis or manufactured) for symptom reduction in people with schizophrenia. Search methods We searched the Cochrane Schizophrenia Group Trials Register, 12 August 2013, which is based on regular searches of BIOSIS, CINAHL, EMBASE, MEDLINE, PUBMED and PsycINFO. We searched all references of articles selected for inclusion for further relevant trials. We contacted the first author of included studies for unpublished trials or data. Selection criteria We included all randomised controlled trials involving cannabinoids and schizophrenia/schizophrenia-like illnesses, which assessed: 1) treatments to reduce cannabis use in people with schizophrenia; 2) the effects of cannabinoids on people with schizophrenia.