Research Index | Medline Index


Cannabis Research - psychosis & schizophrenia


Authors
Taschner KL
Title
[Psychopathology and differential diagnosis of so-called Cannabis psychoses].
Language
German
Source
Fortschritte der Neurologie-Psychiatrie
Date
1983 Jul
Issue
51(7)
Pages
235-48
Abstract
From 237 patients examined for drug-induced psychoses, 50 cannabis psychoses were examined according to the criterion "main cause of addiction" and 107 were examined according to the criterion "consumption during the last three months before hospitalization". The cannabis psychoses were compared to the other drug-induced psychoses as well as to a control group consisting of 219 schizophrenic patients. General agreement was found with the other drug-induced psychoses as well as with the group of schizophrenic patients. The variation from the symptomatology of the schizophrenics is generally common to both the cannabis psychoses and the other drug-induced psychoses. Judging by the results of our investigations, it must be concluded that there is no disease "cannabis psychosis" in its own right, just as the disease "drug-induced psychosis" also does not exist in its own right. While there is a certain slight drug-specific psychopathological undertone, it does not entitle us to speak of a syndromatic or indeed a nosological entity. The psychopathological cross section does not permit a differentiation in the individual psychoses groups mentioned, although this has often been attempted in the literature. That there are no relevant psychopathological differences between cannabis psychoses and endogenous schizophrenia could, for one, be based on the fact that we are observing the final stage of one and the same underlying pathological process. In this case both syndromes would in practice be endogenous psychoses, with the cause not being known in one case. The psychopathologic similarity of these two psychoses forms could, however, also be based on the assumption that cannabis psychoses are triggered schizophrenias, so that we could in both cases be dealing with one and the same disease. We see the solution to the problem of diagnosing symptomatic psychoses, and in particular cannabis psychoses, in making a diagnosis that takes the etiology into consideration in addition to the syndrome diagnosis.

Authors
Mathers DC, Ghodse AH, Caan AW, Scott SA
Title
Cannabis use in a large sample of acute psychiatric admissions.
Source
British Journal of Addiction
Date
1991 Jun
Issue
86(6)
Pages
779-84
Abstract
A sample of 908 patients drawn from two London Psychiatric Hospitals is described in terms of age, sex, self-reported drug and alcohol history, drug urinalysis results and initial psychiatric diagnosis. Some (34.5%) of respondents admitted to using cannabis at least once in their lifetime and 13% of those tested had urines positive for cannabis on admission. Cannabis use is commoner in young males. These is a higher likelihood that an initial diagnosis of 'psychosis' will be made at admission if patients either report use of cannabis or present a urine sample positive for cannabis.

Id Code
91059143
Authors
Lewis G, Croft-Jeffreys C, David A
Title
Are British psychiatrists racist? [see comments]. CM - Comment in: Br J Psychiatry 1990 Dec;157:936-7, Comment in: Br J Psychiatry 1991 Jan;158:135, Comment in: Br J Psychiatry 1991 Feb;158:289-90
Source
British Journal of Psychiatry
Date
1990 Sep
Issue
157
Pages
410-5
Abstract
Out of a sample of 220 British psychiatrists, 139 completed a questionnaire regarding a case vignette of psychotic illness. The sex and 'race' of the vignette were varied and the responses compared. The Afro-Caribbean case was regarded as that of an illness of shorter duration, and requiring less neuroleptics than the white case. Respondents judged the Afro-Caribbean case as potentially more violent and thought criminal proceedings were more appropriate. The female vignette was perceived as less violent, less criminal, and less likely to need neuroleptics. Cannabis psychosis and acute reactive psychosis tended to be diagnosed more often and schizophrenia less often in Afro-Caribbean cases, refuting the claim that psychiatrists tend to overdiagnose schizophrenia in this group. Such 'race thinking' (a form of stereotyping which is distinct from ideological racism) could lead to inappropriate management.

Id Code
94356351
Authors
Thomas H
Title
Psychiatric symptoms in cannabis users [see comments]. [Review] CM - Comment in: Br J Psychiatry 1993 Nov;163:698
Source
British Journal of Psychiatry
Date
1993 Aug
Issue
163
Pages
141-9
Abstract
The usual phenomena of cannabis intoxication include experiences which in a non-intoxicated state would be considered as psychiatric symptoms. These can be distinguished from adverse reactions to cannabis, the commonest of which is an acute anxiety state. Acute psychotic episodes can also follow ingestion of the drug but are infrequent. These can be classified as acute confusional states and episodes occurring in clear consciousness. Neither presentation consistently shows enough specific features to warrant the diagnosis of 'cannabis psychosis' as a distinct clinical entity. The evidence that cannabis has a causative role in chronic psychotic or affective disorders is not convincing, although the drug may modify the course of an already established illness. Further controlled studies would be required to clarify the aetiological significance of the drug in these conditions.
References
90

Id Code
88061263
Authors
Schneier FR, Siris SG
Title
A review of psychoactive substance use and abuse in schizophrenia. Patterns of drug choice. [Review]
Source
Journal of Nervous & Mental Disease
Date
1987 Nov
Issue
175(11)
Pages
641-52
Abstract
We reviewed studies measuring unsupervised use of psychoactive substances in schizophrenic and control populations and organized the results by substance class. Despite much variation in their methodologies, these studies broadly agreed that schizophrenic groups' use of amphetamines and cocaine, cannabis, hallucinogens, inhalants, caffeine, and tobacco was significantly greater than or equal to use by control groups consisting of other psychiatric patients or normal subjects. Schizophrenic groups' use of alcohol, opiates, and sedative-hypnotics was significantly less than or equal to use by control groups. We discuss the implications of this nonrandom pattern of drug choice for the hypothesis of substance abuse as a form of self-medication in schizophrenia. [References: 93]

Id Code
95078211
Authors
McGuire PK, Jones P, Harvey I, Bebbington P, Toone B, Lewis S, Murray RM
Title
Cannabis and acute psychosis.
Source
Schizophrenia Research
Date
1994 Sep
Issue
13(2)
Pages
161-7
Abstract
The Present State Examination was used to assess the psychopathology of 23 psychotic patients who were cannabis positive on urinary screening, and 46 matched drug-free controls. Cases and controls were indistinguishable in terms of psychopathology, DSMIII diagnoses, onset of recent illness, the proportion of first admissions, ethnicity, and socio-economic class, differing only in their histories of substance use. These data suggest that psychosis which develops or recurs in the context of cannabis use does not have a characteristic psychopathology or mode of onset, and is not restricted to a particular ethnic or socio-demographic group. There is thus little evidence to support the validity of 'cannabis psychosis' as a diagnostic entity.

Id Code
92180676
Authors
Peralta V, Cuesta MJ
Title
Influence of cannabis abuse on schizophrenic psychopathology.
Source
Acta Psychiatrica Scandinavica
Date
1992 Feb
Issue
85(2)
Pages
127-30
Abstract
A study was carried out on a group of 95 schizophrenic patients (DSM-III-R criteria) under the age of 35, 23 of whom were cannabis abusers in the past year. The objective of the study was to evaluate the effect of cannabis on positive and negative schizophrenic symptoms, evaluated using Andreasen's Scales for the Assessment of Positive and Negative Symptoms (SAPS and SANS). There were no statistically significant differences between the groups on the SAPS; the group of cannabis abusers had higher scores except for the delusions subscale. On the SANS nonabusers scored higher, with a significant difference on the alogia subscale. The results suggest that the consumption of cannabis by schizophrenic patients could attenuate negative symptoms, which would support the self-medication hypothesis of cannabis abuse.

Authors
- Gruber AJ, Pope HG Jr, Brown ME
Title
- Do patients use marijuana as an antidepressant?
Language
- Eng
Date
- 1996
Issue
- 1062-6417
Source
- Depression
Pages
- 77-80
Country
- UNITED STATES
Abstract
- Several lines of evidence suggest that cannabis may have antidepressant effects. However, methodologic limitations in available studies make the results difficult to interpret. We review this literature and present five cases in which the evidence seems particularly clear that marijuana produced a direct antidepressant effect. If true, these observations argue that many patients may use marijuana to "self-treat" depressive symptoms.
Research Institute
- Biological Psychiatry Laboratory, McLean Hospital, Belmont, Massachusetts 02178, USA.
References
- 34
Source
- Depression 1996;4(2):77-80