Combined cannabis/methaqualone withdrawal treated with psychotropic analgesic nitrous oxide

This article reports the first single-blind study using psychotropic analgesic nitrous oxide (PAN) for treating acute withdrawal states following the abuse of methaqualone combined and smoked with cannabis. Smoked methaqualone combined with cannabis is called "white pipe" (WP). South Africa is the only country in the world where WP is a major form of substance abuse. This article demonstrates in 101 consecutively treated patients given placebo (100% oxygen) followed by PAN that this therapy produced a measurable therapeutic effect (more than 50% improvement) in 87 patients. This study confirms that WP is a form of substance abuse confined mainly to young adult male subjects.     

Trends in adolescent alcohol and other drug use: findings from three sentinel sites in South Africa (1997-2001)

This paper aims to provide surveillance information about the extent and consequences of alcohol and other drug (AOD) use by adolescents for three sentinel sites in South Africa (Cape Town, Durban and Gauteng province). From 1997 to 2001, data were gathered from multiple sources, including specialist treatment centres, trauma units, school students, rave party attenders, and arrestees. Since the start of surveillance, an increasing proportion of South African adolescents are using AODs. Surveys point to high levels of alcohol misuse among high school students, with alcohol being the most common substance of abuse. Cannabis is the most frequently reported illicit drug of abuse among adolescents. This is reflected in the large proportion of adolescents receiving treatment for cannabis, cannabis-positive arrestees, and cannabis-positive trauma patients. Cannabis smoked together with methaqualone is the second most common primary drug of abuse in Cape Town. Arrestee data highlights the potentially negative effect of adolescent methaqualone use. Cocaine and heroin are emerging as problem drugs of abuse among adolescents in large metropolitan centres. Ecstasy (MDMA) use occurs mainly among adolescents who attend rave parties and clubs. The study points to the need for AOD intervention programmes that target young people and the need for continued monitoring of adolescent AOD use in the future.     

Lower negative symptom scores among cannabis-dependent patients with schizophrenia-spectrum disorders: preliminary evidence from an African American first-episode sample

Substance use disorders, especially cannabis abuse and dependence, are common comorbid diagnoses among patients in the early course of schizophrenia. Some prior research suggests that individuals with schizophrenia and related disorders and comorbid substance abuse may have fewer negative symptoms than those without substance abuse. This pilot study examined the association between cannabis dependence and negative symptoms in a relatively homogenous sample of 18 African American first-episode, first-hospitalization patients. Those with cannabis dependence had significantly lower Positive and Negative Syndrome Scale (PANSS) negative subscale scores compared to those without cannabis dependence (p<0.012). The two groups did not differ on PANSS positive and general psychopathology subscale scores. Additional research is needed on the correlates of substance abuse among first-episode patients, including socially disadvantaged African American patients.     

Cannabis and schizophrenia: demographic and clinical correlates

The high prevalence of psychoactive substance abuse or dependence among schizophrenic patients has now been well established. Mueser et al. stressed the need to assess the abuse of specific classes of substances and analyse the data accordingly. The objective of this study was to compare the socio-demographic correlates and the clinical features in a group of schizophrenic patients with a lifetime cannabis abuse or dependence according to the DSM III-R with a group of schizophrenic patients who had never presented any abuse or dependence. SUBJECTS AND METHODS: The study included 124 subjects with diagnoses of schizophrenia or schizoaffective disorders according to the DSM III-R. Inclusion criteria for participation in the study were age 18 years or older and willingness to provide consent to participate in the study. The inpatients were evaluated when their condition was stabilised. Assessment tools were the psychoactive substance use disorder section of the Composite International Diagnostic Interview (CIDI), the Positive and Negative Syndrome Scale (PANSS), the Global Assessment of Functioning Scale (GAF). Subjects with cannabis abuse or dependence during their lifetime were compared with subjects without abuse or dependence, using chi(2) test for categorical variables and analyses of covariance (ANCOVA) for quantitative variables. RESULTS: Forty-nine subjects (42,6%) presented lifetime abuse or dependence on one or more substances. Since 19 patients with alcohol, stimulant, sedative or opiate abuse or dependence were excluded, the study finally included 96 subjects including a first group of schizophrenic patients with cannabis abuse (n=6) or dependence (n=24) and a second group without any psychoactive substance abuse (n=66). Thirteen (11.3%) patients presented cannabis abuse or dependence within the 6 months prior to the assessment. The mean SD age of onset of cannabis abuse or dependence was 19.6 +/- 3.0 years. Cannabis abuse/dependence preceded the first psychiatric treatment in 70% of the subjects (n=21). 83.3% of the schizophrenic patients with cannabis abuse or dependence were male (n=25) compared to 62.1% in the group without substance abuse (n=41) (chi(2)=4.32, df=1, p=0.04). Schizophrenic patients with cannabis abuse were significantly younger (mean age: 28.9 +/- 6.3 vs 37.0 +/- 12.7, ANCOVA, F=7.2, df=1,96 p=0.009). There was no significant difference between the two groups for marital status, (chi(2)=5.34, df=2, p=0.07), level of education, (chi(2)=0.93, df=2, p=0.62) professional status, (chi(2)=8.7, df=5, p=0.11), on PANSS total score (ANCOVA, F=0.42, df=1,93, p=0.52), GAF score (ANCOVA, F=0.06, df=1,92, p=0.80), mean number of hospitalizations (ANCOVA, F=3.25, df=1,85, p=0.08), mean age of first psychiatric contact (ANCOVA, F=0.74, df=1,93, p=0.39), and neuroleptic dosages (ANCOVA, F=0.03, df=1,90, p=0.87). In contrast, the total duration of hospitalization was significantly longer for the group with cannabis abuse. Patients with cannabis abuse were more likely to have an history of suicide attempts than subjects without substance abuse (chi(2)=11.52, df=1, p=0.0007). DISCUSSION: The prevalence rates for substance abuse and the socio-demographic characteristics of the population of our study are consistent with findings of previous studies. Male gender and age were significantly related to history of cannabis abuse or dependence. Cannabis abuse frequently preceded the onset of psychiatric treatment. However, both schizophrenia and substance abuse tend to develop gradually, with no clear demarcation for the onset of schizophrenia. The absence of any link between the scores for the subscales of the PANSS and cannabis abuse, both in our study and in some retrospective previous studies, is not suggestive of cannabis abuse as a self-medication of positive or negative symptoms of schizophrenia. Self-medication could concern other symptoms, such as cognitive deficits. In addition, the hypothesis of self-medication has especially been suggested in cocaine abuse or dependence. Some limitations to this study can be discussed. First, although the recruitment was systematic and done in a public mental health service, the patients of our study are not necessarily representative of all schizophrenic patients. Secondly, as in any retrospective study, the prevalence of lifetime substance abuse may have been under-estimated. Urinary toxicology tests may have been able to improve the sensitivity of the diagnosis of recent substance abuse, but structured interviews are more appropriate for the diagnosis of lifetime substance abuse in schizophrenic patients than urinary toxicology tests. CONCLUSION: The socio-demographic characteristics of cannabis abuse or dependence in schizophrenia are similar to those found in general population. Cannabis using schizophrenic patients were more likely to be younger and male than non users. The duration of hospitalization was significantly longer for the group with cannabis abuse. Prevalence of suicide attempts in schizophrenia is closely correlated to cannabis abuse.     

Opioid abuse and hospitalization rates in patients with schizophrenia

Background: Substance abuse worsens the course of schizophrenia, but it is not known whether or not there are differences between specific substances concerning their association with the hospitalizations of patients with schizophrenia. Aims: The primary aims of this study were to examine the possible associations between amphetamine, cannabis, and opioid abuse, and the risk of hospitalizations among patients with schizophrenia. Methods: The study population consisted of 146 patients with ICD-defined schizophrenia from two different geographical sites in Finland, and it included both inpatients and outpatients. Data were collected retrospectively from the patients’ medical files. Substance abuse was defined as either harmful use or dependence according to ICD-10. Results: The cumulative prevalence of substance abuse was 10.9% (16/146) for cannabis, 8.9% (13/146) for amphetamine, and 4.1% (6/146) for opioids. Among patients with schizophrenia and abuse of any substance, the number of hospitalizations was about 1.5-fold when compared to those without substance abuse. The incidence rate ratio for hospitalizations was 2.9 (95% CI 2.47–3.63) for opioids, 2.0 (1.71–2.41) for amphetamine, and 1.6 (1.33–1.84) for cannabis, when compared with no abuse of each substance. The risk of hospitalizations was significantly higher for opioids when compared with amphetamine (p < 0.001) or cannabis (p < 0.001). Conclusions: Harmful use or dependence of opioids among patients with schizophrenia is associated with significantly higher risk of hospitalizations than either harmful use or dependence of amphetamine or cannabis.     

Cognitive compromise in bipolar disorder with chronic cannabis use: cause or consequence?

This article briefly reviews the neuropsychological deficits associated with bipolar disorder and examines how substance abuse, in particular chronic cannabis use, may contribute to these. The focus of the article is cannabis, owing to its popularity in patients with bipolar disorder, although many studies focus on its use in conjunction with other substances. The findings are contextualized within bipolar disorder, examining functional outcome.     

Motivational interviewing for cannabis users with psychotic disorders

BACKGROUND: People suffering from psychiatric disorders abuse alcohol or illicit substances twice as frequently as the general population. This problem is even more frequent in the early phase of psychotic disorders where prevalence of substance abuse ranges, according to various studies, from 35 to 65% during first psychotic episode. Cannabis is currently the most frequently used substance, and although its impact is often minimised, many data suggest it constitutes a risk for psychosis at three levels: (a) possible toxic psychosis in healthy individuals, (b) relapse of positive symptoms in schizophrenia and (c) raises the risk of schizophrenia when used early during adolescence. Despite a persistent controversy regarding some of these findings, they have constituted a sufficient body of evidence to support the development of specific interventions for psychotic patients. Various authors have described the fundamental elements of such dual diagnosis treatments, and some intervention programs have recently been developed. However, their relative complexity and the long duration of such interventions are often not well adapted to patients with limited motivation and low level of insight. Moreover, many obstacles arise that complicate their application to early psychotic disorders: minimisation of deleterious effect of cannabis by young people, distrust linked to psychotic symptoms, cognitive disturbances, stigmatisation of psychiatry, and use of cannabis as a means to socialise with peers. It is therefore important to adapt interventions to the specific needs of such patients and particularly to adopt a realistic attitude, aiming at increasing motivation to change habits and minimising associated risks rather than total abstinence. Our objective is to develop a pragmatic, non-judgemental approach, based on motivational interviewing techniques that is adapted to early psychosis with comorbid cannabis abuse, aimed at reducing the risks associated with abuse. In this article, we describe the basic principles and various stages of a brief motivational intervention developed for the treatment of cannabis abusers, going through the early phase of a psychotic disorder. The conceptualisation of the intervention was based on an extensive literature review and our experience in the treatment of such patients, as well as in the treatment of alcohol abuse through motivational interview. METHODS: Our intervention uses motivational interviewing techniques (empathic, non-judgemental approach, aimed at developing insight regarding potential consequences of cannabis abuse through the exploration of both its positive and negative aspects) and can be adapted to the patient's stage of motivation for change. Its basic principles are: (a) to address questions related to psychosis and cannabis simultaneously; (b) to take into account cognitive dysfunction related to illness and treatment; (c) to adapt techniques of reflective listening; and (d) to structure the interview through frequent summaries and by considering successively the positive and negative aspects of cannabis. The intervention is composed of four sessions: (1) creation of an alliance and evaluation of the level of cannabis abuse; (2) development of motivation to change by increasing contradictions between patient's affirmations; (3) definition of objectives according to the level of motivation to change; and (4) adaptation of the subsequent intervention according to the degree of motivation to change. RESULTS: A pilot study showed that this intervention can be implemented in the target population. It revealed that it facilitated the establishment of a trustful relationship, in the frame of which ambivalence regarding cannabis abuse could be explored. The fact that the therapist makes the first step, shows empathy and tries to understand patient's motivations to use cannabis, leads patients to expose their ambivalence with less reluctance and to become more aware of the possible links between cannabis and psychotic disorders. CONCLUSION: This method is particularly well adapted to patients who are in a precontemplative stage. Additional studies are needed in order to evaluate its efficacy in terms of decrease in the risks related to cannabis abuse.     

Comorbidity of substance abuse and other psychiatric disorders in acute general psychiatric admissions: a study from Lebanon

This is the first published study from an Arab Near Eastern country to examine the comorbidity of substance abuse with other psychiatric disorders. All inpatients with substance abuse/dependence (present or past) admitted to the psychiatry unit at St. George Hospital (Lebanon) between 1979 and 1992 (N = 222) constituted the study sample. Of these, 64.9% were found to have comorbid psychiatric disorders with specific relations between individual substances and psychiatric diagnoses identified such as cocaine and bipolar disorder (42.1%), and cannabis and schizophrenia (44.8%). Patients with no axis I disorder were predominantly heroin users, most of them having antisocial personality disorder. Polydrug abuse was found among 44.9% of patients, and most of the benzodiazepine abusers belonged to this category. The pattern of comorbidity of psychiatric and substance use disorders in this Near East inpatient population compares well with findings from the Western hemisphere: cultural factors (including war) do not seem to have much of an effect on the different forms of dual diagnoses. This adds weight to the already existing literature on the need for careful psychiatric assessment in the treatment of substance abuse.     

Which temperamental characteristics are associated with substance use in subjects with psychotic and mood disorders?

The aim of this study was to assess the associations between substance use disorders and temperamental characteristics in subjects with non-affective psychotic disorders or mood disorders. Consecutively hospitalized patients were interviewed with a structured diagnostic interview to define DSM-IV diagnoses, including those of substance use. Temperamental characteristics were measured using the Sensation-Seeking Scale (SSS), the Barratt Impulsivity Scale (BIS) and the Physical Anhedonia Scale. Inpatients (n=103) with non-affective psychotic disorders (n=45) or mood disorders (n=58) were included. Among these patients, 25.2% presented with a lifetime (LT) history of alcohol abuse/dependence and 23.3% presented with a LT history of cannabis abuse/dependence. A LT history of alcohol misuse was independently associated with higher scores at the 'experience seeking' and 'disinhibition' subscales of the SSS. A LT history of cannabis misuse was independently associated with higher scores on the 'disinhibition' subscale of the SSS and on the 'non-planning activity' subscale of the BIS. These results suggest that sensation-seeking and impulsivity are temperamental characteristics that may favor substance use in patients with psychotic or mood disorders, independently from categorical diagnoses.     

Effect of comorbid substance use on neuropsychological performance in subjects with psychotic or mood disorders

Objective - Patients presenting with psychotic or mood disorders present with neuropsychological deficits such as executive and memory disturbance. Deficits of these functions have also been reported in patients presenting with alcohol use or substance use disorders. A large percentage of patients with non-affective psychotic or mood disorders present with a comorbid substance use disorder. These subjects are often a priori excluded from most neuropsychological studies. However, using such an exclusion criterion may induce a selection bias linked to the high prevalence of this dual diagnosis. It is therefore necessary to further explore the impact of substance abuse on neuropsychological performance in subjects with psychotic or mood disorders. Method - Patients consecutively hospitalized for a non-affective psychotic disorder or a mood disorder were included. A standardised method was used to collect information on addictive behaviour, clinical and social characteristics. DSM IV diagnoses, including those of substance use, were made using a structured diagnostic interview and all other available clinical and historical information collected during the hospital stay. Memory performance was tested using the Batterie d'Efficience Mnésique 84 (Battery of memory efficiency 84 items, BEM 84). Executive abilities were explored using the Wisconsin Card Sorting Test (WCST) and the Stroop test. ANCOVAs with cannabis use disorder or alcohol use disorder as main factor were used to examine associations with neuropsychological test scores. Results - We have included 77 patients fulfilling the diagnostic criteria for non-affective psychotic disorders (schizophrenia, schizoaffective disorder, delusional disorder, other psychotic disorder, n=35) or mood disorders (n=42). Among these patients, 27.3% presented with a lifetime history of alcohol abuse/dependence (current prevalence: 14.3%) and 23.4% presented with a lifetime history of cannabis abuse/dependence (current prevalence: 11.7%). We have assessed the specific impact of alcohol and cannabis use on neuropsychological performance. No significant differences on memory and executive performance were found between patients presenting with and without a lifetime history of alcohol abuse/dependence. These results were not modified after adjustement for potential confounding factors (age, gender, educational level, age at onset, diagnosis, current versus past addictive behaviour). Patients with a lifetime history of cannabis abuse/dependence had significantly higher (i.e. better performance) general BEM 84 score (F=3.89, df=1, p=0.05), higher complex figure delayed recall scores (F=6.62, df=1, p=0.01) and higher recognition scores (F=3.9, df=1, p=0.05) than patients presenting without a lifetime history of cannabis use. After adjustment on covariables (age, gender, educational level, age at onset, diagnosis, current versus past addictive behaviour), the differences on memory performance between the two groups were no longer significant, the differences found before adjustment were mainly explained by the confounding effect of age. Patients presenting with a lifetime history of cannabis abuse/dependence had significantly lower interference scores on the Stroop test than subjects without cannabis use (F=5.67, df=1, p=0.02). This finding was not modified after adjustment for confounding factors. Information on substance use was collected by interviewing the patient and was completed by using all other available source of information, but no urine testing was performed. Thus, substance use could have been underestimated or unrecognized in some patients. We did not distinguish patients who presented with substance abuse from those who presented with dependence because there were few of the latter. Distinguishing these two populations would be of interest because dependence may have a more deleterious effect than abuse in neuropsychological performances. Finally, we did not included normal control subjects so we can not assess if our cohort present with memory and executive deficits compared to normal subjects. Conclusion - Comorbid alcohol or cannabis abuse/dependence has limited effects on memory and executive abilities in subjects with psychotic or mood disorder. The only significant difference between subjects with and without a dual diagnosis was that subjects with cannabis use disorder performed poorly on the Stroop test. No other significant difference in executive and memory performance was found after adjustment for confounding factors. Since there is a high prevalence of a comorbid substance use disorder in subjects with psychotic or mood disorder, the exclusion of these patients in neuropsychological studies may not be systematically justified.     

Cannabis and schizophrenia: results of a follow-up study

A total of 39 schizophrenic patients with a history of current cannabis abuse at index admission was compared with a control group of schizophrenics without substance abuse matched for age, gender, and year of admission. At follow-up after 68.7 ± 28.3 months, 27/ 39 cases and 26/39 controls could be investigated. 8/27 cases (30%) had continued cannabis abuse, 6/27 (22%) had become alcohol abusers. Only one patient of the control group had started abusing alcohol. Patients with previous cannabis abuse had significantly more rehospitalizations, tended to worse psychosocial functioning, and scored significantly higher on the psychopathological syndromes “thought disturbance” (BPRS) and “hostility” (AMDP). These results confirm the major impact of cannabis abuse on the long-term outcome of schizophrenic patients. Received: 16 December 1997 / Accepted: 19 November 1998     

Histories of substance abuse in patients with postpsychotic depressions

Forty-six schizophrenic or schizoaffective patients with operationally defined episodes of postpsychotic depression were assessed for previous histories of substance abuse. Thirty-five percent had histories of previous cannabis (marijuana) abuse. Additionally, 13% had also abused cocaine, 13% amphetamines, 11% hallucinogens, 4% sedatives, and 2% opiates. Patients with histories of substance abuse were younger and showed higher index ratings on a subscale of endogenous depressive features. These findings are considered in the context of a possible self-medication hypothesis of substance abuse. A history of substance abuse did not appear to be a contraindication to a therapeutic trial of adjunctive imipramine (Ciba Geigy Corp., Summit, NJ) for postpsychotic depression.     

Lifetime positive symptoms in patients with schizophrenia and cannabis abuse are partially explained by co-morbid addiction

Recent prospective findings have shown that cannabis use by young people could be a risk factor for psychotic symptoms in adulthood, but the long-term impact of cannabis abuse on the clinical features of declared schizophrenia remains to be explored. We assessed the independent influence of cannabis abuse on the clinical symptoms of schizophrenia, after controlling for frequently co-occurring addictive disorders. Patients with schizophrenia, and with (N=66), or without (N=139) cannabis abuse, were compared for lifetime positive and negative symptoms, taking into account presence of any other addictive disorders. The incidence of the abuse of drugs other than cannabis was nearly five times greater amongst patients with both schizophrenia and cannabis abuse. When the analyses were limited to subjects with no other abuse, less avolution and fewer apathy symptoms were still detected in patients with schizophrenia and cannabis abuse than in those with no abuse (p=0.0001). In contrast, between-group differences for positive symptoms were abolished when multiple substance abuses were taken into account. The strong association between cannabis abuse and fewer negative symptoms in schizophrenia was thus replicated in this sample, but once co-morbid addictive disorders had been controlled no influence of cannabis abuse on hallucinations was detected. Distinguishing the effects of co-occurring addictive disorder(s) in patients with schizophrenia and cannabis dependence may thus be important when attempting to analyse the impact of cannabis abuse.     

Substance abuse in patients with schizophrenia

The comorbidity of schizophrenia and substance abuse has attracted increasing attention in the past years, with multiple potential links, including genetic vulnerability, neurobiological aspects, side effects of medications, and psychosocial factors being under discussion. The link between the use of substances and the development of psychoses is demonstrated by the high prevalence of substance abuse in schizophrenia. Apart from alcohol misuse, substances commonly abused in this patient group include nicotine, cocaine, and cannabis. In particular, heavy cannabis abuse has been reported to be a stressor eliciting relapse in schizophrenic patients. In general, substance use in psychosis is associated with poorer outcomes, including increased psychotic symptoms and poorer treatment compliance. Since both disorders have been observed to be closely interdependent, a particular treatment for schizophrenic patients with comorbidity of substance abuse is needed in order to provide more effective care. In this article, we discuss various potential modes of interaction and interdependence, and the possibility of embarking on new therapeutic paths for treating this particular population.     

The vulnerability to alcohol and substance abuse in individuals diagnosed with schizophrenia

Individuals with schizophrenia are at increased risk for developing substance abuse disorders. Here, we consider factors that might elevate their risk for substance abuse. The tendency among schizophrenic individuals to overvalue drug-like rewards and to devalue the potential negative consequences of substance abuse may be a contributing factor to their substance abuse risk. This bias, which may partly reflect the convergence of glutamatergic and dopaminergic input to the limbic striatum, also may contribute to disadvantageous decision-making and other impulsive behavior. This propensity to seek drug-like rewards is augmented by alterations in nicotinic cholinergic, GABAergic, glutamatergic, and cannabinnoid receptor function associated with schizophrenia that increase the abuse liability of low doses of nicotine, ethanol, and perhaps cannabis, and augment the dysphoric effects of higher doses of ethanol and cannabis. The distortions in reward processing and altered response to substances of abuse also increase the likelihood that individuals with schizophrenia will self-medicate their subjective distress with abused substances. The focus on distinctions between motivation and reward with respect to substance abuse risk by schizophrenic patients suggests a need for a reconsideration of the construct of "negative symptoms" for this dually-diagnosed patient group.     

Epistatic interactions involving DRD2, DRD4, and COMT polymorphisms and risk of substance abuse in women with binge-purge eating disturbances

Substance abuse is common in individuals with bulimia-spectrum (binge-purge) eating disturbances, a co-occurrence that has been attributed to shared neurobiological substrates--notably alterations in dopaminergic activity. We examined the implications of variations of selected, dopamine-relevant polymorphisms (DRD2 Taq1A, DRD4 7R, and COMT) for risk of substance abuse in women with binge-purge eating syndromes. We genotyped 183 women (66.1% showing full-threshold BN and 33.9% showing sub-syndromic variants), and assessed lifetime presence of alcohol, cannabis, cocaine, and stimulant abuse or dependence using structured interviews. Tests for main and interaction effects of various allele combinations revealed that individuals who carried high function COMT and low-function DRD4 7R alleles (a combination expected to be associated with higher risk) did indeed show more lifetime substance abuse and, specifically, more cannabis abuse. Our findings suggest that a gene combination that, in theory, codes for low levels of dopaminergic neurotransmission coincides with sensitivity to substance abuse in a sample displaying binge-purge eating-disorder variants.     

Diagnostic and demographic correlates of substance abuse in schizophrenia and major affective disorder.

The relationship between history of specific types of substance abuse (alcohol, stimulants, cannabis, hallucinogens, narcotics) and demographic and diagnostic variables was evaluated in a large (n = 263) sample of schizophrenic, schizoaffective, major depression and bipolar disorder patients. Prevalence rates were also compared with rates observed in a previous study (1983-1986) conducted using the same methods. Demographic characteristics (gender, age, race, educational level) were strong predictors of type of substance abuse. Patients with a history of cocaine abuse had fewer prior hospitalizations, suggesting that less impaired psychiatric patients may be more prone to illicit substance abuse. Diagnoses were not related to most types of substance abuse, although there was a trend for bipolar patients to have a history of alcohol abuse. The results demonstrate the importance of matching groups on demographic characteristics when exploring diagnostic differences in preference to abuse specific types of substances.     

Cannabis induces different cognitive changes in schizophrenic patients and in healthy controls

It is known that 60 to 80% of schizophrenic patients show deficits in cognition. There may be an increase in these deficits as a result of additional regular use of cannabis. The aim of the study was to evaluate the effect of chronic cannabis consumption on the cognitive functions of schizophrenic patients and healthy control subjects after a minimum abstinence time of 28 days. The study sample consisted of 39 schizophrenics (19 cannabis-abusers and 20 non-abusers) and 39 healthy controls (18 cannabis-abusers, 21 non-abusers). In a 2x2-factorial design (Diagnostic Groups [healthy controls, schizophrenic patients]xCannabis abuse [without, with]) with diagnostic group and cannabis consumption considered between-subject factors) we tested the hypothesis that dually diagnosed patients (i.e. suffering both from schizophrenia and cannabis abuse) perform worse in neuropsychological tests than schizophrenic patients without cannabis abuse. On the whole, schizophrenic patients performed worse than healthy control subjects. Surprisingly, rather than deteriorating neuropsychological performance, regular cannabis abuse prior to the first psychotic episode improved cognition in some tests. This was even more pronounced when regular consumption started before the age of 17. On the other hand, cannabis use deteriorated test performance in healthy controls, especially in cases when regular consumption started before the age of 17. To sum up, regular cannabis abuse has a different effect on cognitive function in schizophrenic patients and healthy controls.     

Postdischarge cannabis use and its relationship to cocaine, alcohol, and heroin use: a prospective study

OBJECTIVE: Research on the effects of cannabis on the brain and behavior has been surprisingly scarce. In humans, laboratory studies document toxicity and psychoactive effects of cannabinoids. However, among substance abuse patients, only a few studies have prospectively examined the relationship of cannabis use to remission or relapse of use of other substances. Because cannabis is a widely used substance, the authors examined whether cannabis use during follow-up after discharge from inpatient treatment affected cocaine, alcohol, and/or heroin use. METHOD: Two hundred fifty patients 18 years old or older from an inpatient psychiatric/substance abuse setting participated in a Psychiatric Research Interview for Substance and Mental Disorders. All patients were diagnosed according to DSM-IV as having current alcohol, cocaine, and/or heroin dependence. Sustained remission was defined as at least 26 weeks without use following hospital discharge. Data were analyzed with Cox proportional hazards models. RESULTS: About one-third of the patients (N=73) used cannabis after hospital discharge. Postdischarge cannabis use substantially and significantly increased the hazard of first use of any substance and strongly reduced the likelihood of stable remission from use of any substance. Examination of specific substances indicated that cannabis use affected first use of alcohol, stable remission, and subsequent relapse of alcohol use as well as first use of cocaine and stable remission but was unrelated to heroin outcomes. CONCLUSIONS: Potential negative clinical implications of cannabis use should be considered when treating dependence on other substances and planning aftercare. Clinical and laboratory research is needed to provide understanding of the mechanisms of cannabinoids in relapse to alcohol and cocaine use.     

Cannabis abuse is not a risk factor for treatment outcome in methadone maintenance treatment: a 1-year prospective study in an Israeli clinic

OBJECTIVE: We addressed the following questions. What are the current and lifetime prevalence of cannabis abuse in an Israeli methadone maintenance treatment (MMT) clinic? Does cannabis abuse change over time during MMT? Is cannabis abuse related to treatment outcome measures such as retention rate and the abuse of drugs? Is the abuse of cannabis related to psychopathology, HIV/HCV risk-taking and infectious diseases? Do cannabis abusers (CAs) have a different psychosocial and demographic profile than nonabusers (NCAs)? Is cannabis abuse part of a polydrug abuse tendency or a distinct substance of abuse? METHOD: Overlapping samples of either the entire clinic population (n = 283) or all the patients who had completed 1 year of MMT treatment (n = 196 of which 20 were re-entering) underwent random and twice-weekly observed urine analysis for various drugs of abuse, responded to self-report questionnaires (SCL-90-R; HIV/HCV risk-taking behaviours; n = 164), interviews (ASI, n = 176; SCID, n = 151) and hepatitis C and HIV testing (n = 149). RESULTS: Lifetime abuse prevalence was found in 75% and current abuse at MMT intake in 25%. Abuse did not increase significantly over a 1-year period. Cannabis abusers were found to be more often polydrug abusers than NCAs. Cannabis abusers did not suffer from more psychological distress, infectious diseases, and did not engage in more HCV/HIV risk-taking behaviour, nor did they leave treatment earlier than NCAs. CONCLUSIONS: Cannabis abuse MMT patients should be treated as polydrug abusers, although no specific influences of cannabis abuse on psychological and medical conditions of MMT patients have been observed. Treatment policy should take these results into consideration.