Relationships between symptoms of schizophrenia and substance abuse

Are Patients with Schizophrenia Reliably Reporting their Cannabis Use? An African Cross-sectional Study

BACKGROUND

Most studies of the prevalence of cannabis use among patients with schizophrenia used a self-report as declared by the patient himself. We hypothesize that patients with schizophrenia did not tell the truth and might underreport their use for many reasons to be discussed later. Indeed, the under-report of cannabis use among these patients can affect the effectiveness of their treatment.

AIMS

To assess the degree of agreement between the prevalence values obtained from patients' reports and the results of the toxicological tests.

METHODS

A cross-sectional study was carried out on 403 patients with schizophrenia. A sociodemographic, psychiatric history and illicit drug use profile was performed for each patient. We assessed the patients with the Positive and Negative Syndrome Scale (PANSS), Calgary Depression score (CDSS), Barratt Impulsiveness Score (BIS-10) and Medication Adherence Rating Scale (MARS). The consumption of cannabis used was confirmed with MINI International Neuropsychiatric Interview (MINI-DSM IV) and using toxicological analysis.

RESULTS

Among the 403 patients who consented to give their urine samples, 49.1% (198/403) tested positive for cannabis, and 41.41% (82/198) underreported their use. The sensitivity and specificity of the questionnaire were 0.58 and 0.74. Based on the comparison between sociodemographic and psychiatric history data of patients who self-report and underreport their cannabis use, no significant difference was observed except for the duration of cannabis use and the score on the medication adherence scale. Moreover, it was found that impulsivity, PANSS score, CDSS score, and the type of schizophrenia are not involved in predicting the underreporting of cannabis use.

CONCLUSION

The rate of patients who under-report cannabis use is important. Therefore, toxicological analysis is becoming relevant for identifying drug use among schizophrenic patients and in the addictive comorbidity research field.

Comorbidity Profiles of Psychotic Patients in Emergency Psychiatry

Objectives: Individuals with psychotic symptoms presenting to emergency psychiatry often have comorbid symptoms, such as substance misuse, depression, and anxiety. Many will also have symptoms linked to previous traumatic experiences such as impulsivity, often found in comorbid personality disorders. Although various studies have looked at specific comorbid symptoms, little is known regarding how these symptoms co-exist in individuals with psychotic symptoms and their link with social functioning. The primary objective of the present study was to identify comorbidity profiles among individuals seeking emergency room services for psychotic symptoms. The secondary objective was to investigate the relationship between comorbid symptoms and social functioning deficits in this same population. Methods: Data from 546 individuals seeking psychiatric help for psychotic symptoms was collected within the Signature Project (large data bank) in a psychiatric emergency. Participants answered brief measures of symptoms of alcohol/substance misuse (AUDIT, DAST), depression (PHQ-9), anxiety (STAI-6), childhood trauma (CEVQ), impulsivity (UPPS) and social functioning deficits (WHODAS). For this study, symptom measures and social functioning at baseline were used. Results: Cluster analyses conducted using three different methods revealed a consensus of five classes of comorbid presentations. Class 1 (n = 90) grouped people who had a high score for childhood trauma, with fairly high scores for anxiety and depression. Class 2 (n = 176) included people with mostly psychotic symptoms with little comorbid presentation across other measures. Class 3 (n = 81) grouped people with the highest anxiety and depression scores as well as high drug use and impulsivity. Individuals in Class 4 (n = 87) had the highest scores on alcohol and substance abuse, as well as high impulsivity. Class 5 (n = 112) grouped people with very low anxiety and depression scores but average trauma, alcohol, and substance misuse scores. Linear regressions revealed an association between social functioning, and depression, anxiety, and childhood trauma. Conclusions: Comorbid presentations of individuals with psychosis are frequent and diverse. Depression and anxiety, in particular, worsen social functioning deficits in people with psychotic symptoms. Given their impact on functioning, psychiatric treatments should address these comorbidities during hospitalization, as well as when followed in the community.

Alcohol Use Disorder and Schizophrenia or Schizoaffective Disorder

Schizophrenia and schizoaffective disorder are schizophrenia spectrum disorders that cause significant disability. Among individuals who have schizophrenia or schizoaffective disorder, alcohol use disorder (AUD) is common, and it contributes to worse outcomes than for those who do not have co-occurring substance use disorder. Common neurobiological mechanisms, including dysfunction in brain reward circuitry, may explain the high rates of co-occurrence of schizophrenia and AUD or other substance use disorders. Optimal treatment combines pharmacologic intervention and other therapeutic modalities to address both the psychotic disorder and AUD. Further research on the etiology of these co-occurring disorders and on treatment of affected individuals is needed.

Schizophrenia is associated with increased risk of subsequent substance abuse diagnosis: A nation-wide population-based register study

AIMS

We aimed to investigate whether or not a diagnosis of schizophrenia increases the risk of a substance abuse diagnosis.

DESIGN

Prospective cohort study using a longitudinal study design.

SETTING AND PARTICIPANTS

Individuals born in Denmark from 1955 to 1999 and registered in the Danish registers between 1 January 1968 and 1 July 2013.

MEASUREMENTS

We investigated the associations between schizophrenia and ICD diagnoses of substance abuse, both established through various Danish registers. The Cox regression model was used and adjusted for calendar year, gender, urbanicity, co-abuse, other psychiatric diagnoses, parents' substance abuse and psychiatric history, parents' immigration and parents' socio-economic position. Individuals diagnosed with substance abuse less than a year after diagnosis of schizophrenia were classified as not diagnosed with schizophrenia.

FINDINGS

The cohort consisted of 3 133 968 individuals. During follow-up (103 212 328 person-years at risk), a total of 14 007 individuals developed schizophrenia, with 2885 subsequently diagnosed with substance abuse. A diagnosis of schizophrenia was positively associated with the risk of developing substance abuse [hazard ratio (HR) = 3.69, 95% confidence interval (CI) = 3.56-3.83]. Additionally, adjusting for a co-abuse markedly affected the associations, making schizophrenia primarily associated with an increased risk of abuse of cannabis, alcohol, stimulants and other substances (adjusted HR = 2.48, 95% CI = 2.34-2.64 for cannabis; HR = 1.94, 95% CI = 1.87-2.02 for alcohol; HR = 1.77, 95% CI = 1.61-1.95 for stimulants; HR = 1.36, 95% CI = 1.20-1.54 for other substances). The association was still significant 10-15 years subsequent a diagnosis of schizophrenia (HR = 2.50, 95% CI = 2.26-2.76).

CONCLUSIONS

In Denmark a diagnosis of schizophrenia is significantly associated with increased risk of subsequent diagnosis of substance abuse.

Alcohol use in schizophrenia: prevalence, patterns, correlates and clinical outcomes in Goa, India

Aims and method

To explore the patterns of alcohol consumption and its impact on clinical outcomes in schizophrenia in low- and middle-income countries. We performed a cross-sectional survey of 315 patients with schizophrenia and calculated the prevalence of alcohol consumption and alcohol use disorder. The patients' sociodemographic profiles and clinical outcomes, including Brief Psychiatric Rating Scale (BPRS) scores, were compared between abstainers and drinkers using the χ2- andt-tests.

Results

The 1-year prevalence of drinking, hazardous drinking and alcohol dependence was 16.8% (95% CI 12.9–21.4), 5.7% (95% CI 3.4–8.9) and 2.5% (95% CI 1.1–4.9), respectively. Male gender, single or post-marital status, higher education and being economically active were significantly associated with alcohol consumption. Alcohol drinkers were significantly more likely to be on combination psychotropics compared with abstainers. The mean total BPRS score was significantly lower in alcohol drinkers compared with abstainers. Drinking alcohol was associated with fewer deficit symptoms.

Clinical implications

Cultural settings have a significant impact on the prevalence of alcohol use disorder in schizophrenia.

A Study of the Impact of Cannabis on Doses of Discharge Antipsychotic Medication in Individuals with Schizophrenia or Schizoaffective Disorder

Patients with schizophrenia or schizoaffective disorder have a high prevalence of comorbid cannabis use disorder (CUD). CUD has been associated with poorer outcomes in patients. We compared doses of antipsychotic medications at the time of discharge from hospital among inpatients with schizophrenia or schizoaffective disorder with or without concurrent cannabis use. We reviewed the medical records of patients (N = 8157) with schizophrenia or schizoaffective disorder discharged from the hospital between 2008 and 2012. The patients were divided into two groups; those with urine drug tests positive for cannabis and those negative for cannabis. Doses of antipsychotic medications were converted to chlorpromazine equivalents. Bivariate analyses were done with Student's t test for continuous variables and χ ² test for categorical variables. Linear regression was carried out to adjust for potential confounders. Unadjusted analysis revealed that the cannabis positive group was discharged on lower doses of antipsychotic medication compared with the cannabis negative group (geometric mean chlorpromazine equivalent doses 431.22 ± 2.20 vs 485.18 ± 2.21; P < 0.001). However, the difference in geometric mean chlorpromazine equivalent doses between the two groups was no longer significant after adjusting for sex, age, race, and length of stay (geometric mean difference 0.99; 95 % CI 0.92-1.10). Though limited by lack of information on duration, amount and severity of cannabis use, as well as inability to control for other non-antipsychotic medications, our study suggests that cannabis use did not significantly impact on doses of antipsychotics required during the periods of acute exacerbation in patients with schizophrenia or schizoaffective disorder.

Course of cannabis use and clinical outcome in patients with non-affective psychosis: a 3-year follow-up study

BACKGROUND

Prospective studies on the relationship between course of cannabis use and clinical outcome in patients with non-affective psychotic disorders are inconclusive. The current study examined whether (1) persistent, recently started, discontinued and non-cannabis-using patients with a psychotic disorder differed with regard to illness outcome at 3-year follow-up, and (2) whether timing of cannabis discontinuation was associated with course of clinical outcome.

METHOD

This 3-year follow-up study was part of a multi-center study in the Netherlands and Belgium (Genetic Risk and Outcome of Psychosis; GROUP). We used mixed-model analyses to investigate the association between pattern of cannabis use and symptoms, global functioning and psychotic relapse.

RESULTS

In our sample of 678 patients, we found persistent users to have more positive and general symptoms, worse global functioning and more psychotic relapses compared with non-users and discontinued users [Positive and Negative Syndrome Scale (PANSS) positive, p < 0.001; PANSS general, p < 0.001; Global Assessment of Functioning (GAF) symptoms, p = 0.017; GAF disability, p < 0.001; relapses, p = 0.038]. Patients who started using cannabis after study onset were characterized by worse functioning at baseline and showed an increase in general symptoms (including depression and anxiety) at the 3-year follow-up (p = 0.005). Timing of cannabis discontinuation was not associated with clinical outcome.

CONCLUSIONS

These findings suggest that cannabis use in patients with a psychotic disorder has a long-lasting negative effect on illness outcome, particularly when persistent. Treatment should focus on discouraging cannabis use.

Cognitive Enhancement Therapy Improves Frontolimbic Regulation of Emotion in Alcohol and/or Cannabis Misusing Schizophrenia: A Preliminary Study

Individuals with schizophrenia who misuse substances are burdened with impairments in emotion regulation. Cognitive enhancement therapy (CET) may address these problems by enhancing prefrontal brain function. A small sample of outpatients with schizophrenia and alcohol and/or cannabis substance use problems participating in an 18-month randomized trial of CET (n = 10) or usual care (n = 4) completed posttreatment functional neuroimaging using an emotion regulation task. General linear models explored CET effects on brain activity in emotional neurocircuitry. Individuals treated with CET had significantly greater activation in broad regions of the prefrontal cortex, limbic, and striatal systems implicated in emotion regulation compared to usual care. Differential activation favoring CET in prefrontal regions and the insula mediated behavioral improvements in emotional processing. Our data lend preliminary support of CET effects on neuroplasticity in frontolimbic and striatal circuitries, which mediate emotion regulation in people with schizophrenia and comorbid substance misuse problems.

Pharmacotherapy of Co-Occurring Schizophrenia and Substance Use Disorders

Substance use disorders, common in patients with schizophrenia, can lead to poor outcomes. Here we review the literature on the use of antipsychotics in patients with co-occurring schizophrenia and substance use disorder as well as evidence for the use of adjunctive pharmacological treatments targeting substance use in these patients. We also discuss a neurobiological formulation suggesting that the cooccurrence of these disorders may be related to a dysfunction in the dopamine mediated brain reward circuitry. Typical antipsychotics do not appear to decrease substance use in this population. Randomized, controlled trials provide some support for use of the atypical antipsychotic clozapine for co-occurring cannabis use disorder, naltrexone and disulfiram for alcohol use disorder, and also nicotine replacement therapy, sustained-release bupropion and varenicline for tobacco use disorder. Nonetheless, data regarding treatment in patients with these co-occurring disorders are still limited, and many studies reported to date have been either underpowered or did not include a control condition. Further research is needed to evaluate optimal pharmacotherapeutic strategies for this population.

The impact of alcohol on clinical outcomes in established psychosis: a longitudinal study

BACKGROUND AND AIMS

Alcohol use disorders are common among people with psychosis and are associated with poorer prognoses. In psychosis patients, there are inconsistent findings regarding the link between alcohol disorders and clinical symptomatic outcomes. This study examined the relationships between alcohol consumption and specific clinical outcomes, including affective symptoms, in psychosis.

METHODS

Participants were recruited from secondary care services in the United Kingdom. Two hundred and ten participants whose substance use met inclusion for an alcohol disorder were compared with other substance users (n = 117) on baseline demographic, clinical and substance use variables. The alcohol subgroup was assessed at three time-points, with repeated measures of psychopathology and alcohol use over a 2-year period. Generalized estimating equations (GEE) models were used to examine whether change in alcohol use was associated with change in clinical outcomes. We controlled for a wide range of potential confounds, including other substance use.

RESULTS

A small but specific effect was evident for change in the quantity of alcohol consumed on change in depression (adjusted coefficient for 10 total units over 90 days: 0.0015, P = 0.047). Alcohol consumption was not associated with subsequent severity of psychotic symptoms (adjusted coefficient for Positive and Negative Syndrome Scale general for 10 average daily units 0.2492, P = 0.420) or severity of anxiety symptoms (adjusted coefficient for 10 average daily units 0.0534, P = 0.473).

CONCLUSIONS

For people with psychosis, the most detrimental effect of alcohol consumption appears to be its effect on mood. Some of this effect seems to be reversible, with drinking reduction associated with subsequent mood improvement.

Prevalence of pathological internet use among adolescents in Europe: demographic and social factors

AIMS

To investigate the prevalence of pathological internet use (PIU) and maladaptive internet use (MIU) among adolescents in 11 European countries in relation to demographic, social factors and internet accessibility.

DESIGN

Cross-sectional survey.

SETTING

The 7th Framework European Union (EU) funded project, Saving and Empowering Young Lives in Europe (SEYLE), is a randomized controlled trial (RCT) evaluating interventions for risk behaviours among adolescents in Austria, Estonia, France, Germany, Hungary, Ireland, Israel, Italy, Romania, Slovenia and Spain, with Sweden serving as the coordinating centre.

PARTICIPANTS

A total of 11 956 adolescents (female/male: 6731/5225; mean age: 14.9 ± 0.89) recruited from randomly selected schools within the 11 study sites.

MEASUREMENTS

Internet users were classified by gender into three categories: adaptive, maladaptive and pathological, based on their score in the Young Diagnostic Questionnaire for Internet Addiction (YDQ).

FINDINGS

The overall prevalence of PIU was 4.4%; it was higher among males than females (5.2% versus 3.8%) and differed between countries (χ(2)  = 309.98; d.f. = 20; P < 0.001). PIU correlated significantly with mean hours online and male gender. The highest-ranked online activities were watching videos, frequenting chatrooms and social networking; significantly higher rates of playing single-user games were found in males and social networking in females. Living in metropolitan areas was associated with PIU. Students not living with a biological parent, low parental involvement and parental unemployment showed the highest relative risks of both MIU and PIU.

CONCLUSIONS

Across a range of countries in Europe, using the Young Diagnostic Questionnaire for Internet Addiction yields a prevalence of 'pathological internet use' of 4.4% among adolescents, but varies by country and gender; adolescents lacking emotional and psychological support are at highest risk.

The relationship between medication-related problems and behavioural health condition among patients served by a health care for the homeless centre

Objectives

To evaluate the association between behavioural health conditions and the presence of a medication-related problem (MRP) and the association between the type of MRP and the presence of a dual diagnosis.

Methods

We used an existing database from a behavioural health clinic for homeless persons. Logistic regression was used to assess the relationship between the type of behavioural health condition and MRP presence, and whether the type of MRP varied with the presence of a dual diagnosis.

Key findings

A total of 426 patients were eligible. The majority were black (61%) and women (53%). Patients were 44.7 ± 10.2 years old, taking 3.4 ± 2.4 medications and had 2.3 ± 0.9 behavioural health conditions. The majority (53%) had a dual diagnosis, 44% had depression, 30% had a bipolar disorder, 26% had a personality disorder and 12% had an anxiety disorder. Bipolar [odds ratio (OR) 4.0, 95% confidence interval (CI) 1.8–8.9] and anxiety disorders (OR 3.1, CI 1.0–9.2) and a dual diagnosis (OR 2.1, CI 1.2–3.8) were independently associated with the presence of an MRP. Patients with a dual diagnosis were more likely to have ineffective drug therapy (OR 1.7, CI 1.1–2.8) and less likely to have an adverse effect (OR 0.5, CI 0.3–0.9).

Conclusions

Patients with bipolar or anxiety disorders and/or a dual diagnosis may benefit from a pharmacist intervention to address MRPs. Pharmacists can make recommendations to improve the effectiveness of patients' medication therapy and help to resolve adverse effects.

Effect of cannabis use on the course of schizophrenia in male patients: a prospective cohort study

BACKGROUND

Findings on the impact of cannabis use on the course of schizophrenia are inconsistent and not conclusive.

AIMS

To study the effect of cannabis use on the course of schizophrenia taking into account the effects of the quantity of cannabis use and important confounders.

METHODS

Prospective cohort study with assessments of symptoms, confounders and hospitalizations at baseline, 6 month and 12 month follow up.

RESULTS

In a representative cohort of 145 male patients with schizophrenia, 68 (46.9%) used cannabis. Mean age at onset of schizophrenia in cannabis using patients was significantly lower than in non-cannabis using patients. No other cross-sectional demographic or clinical differences were observed between users and non-users. In a series of longitudinal analyses, cannabis use was not associated with differences in psychopathology, but relapse in terms of the number of hospitalizations was significantly higher in cannabis using patients compared to non-cannabis using patients.

CONCLUSIONS

Patients with schizophrenia using cannabis are more frequently hospitalized than non-cannabis using patients but do not differ with respect to psychopathology. Possible explanations for these findings are discussed.

The Effectiveness of Supported Employment in People With Dual Disorders

OBJECTIVE: This study compared the effectiveness of the Individual Placement and Support (IPS) model of supported employment to control vocational rehabilitation programs for improving the competitive work outcomes of people with a severe mental illness and co-occurring substance use disorder. METHODS: A secondary data analysis was conducted drawing from four randomized controlled trials comparing IPS supported employment to conventional vocational rehabilitation programs for severe mental illness, and focusing on the 106 clients with a recent (past 6 months) substance use disorder. Competitive work outcomes were tracked across an 18-month follow-up period. Analyses compared the IPS and comparison vocational programs on cumulative work over the 18 months, including attainment of work, hours and weeks worked, job tenure, wages earned, and days to first job. RESULTS: In the total study group, clients who participated in IPS had better competitive work outcomes than those who participated in a comparison program, with cumulative employment rates of 60% vs. 24%, respectively. Among clients who obtained work during the study period, those receiving IPS obtained their first job significantly more quickly and were more likely to work 20 or more hours per week at some point during the 18-month follow-up. CONCLUSIONS: The IPS model of supported employment is more effective than alternative vocational rehabilitation models at improving the competitive work outcomes of clients with a dual disorder.

Variable individual sensitivity to cannabis in patients with schizophrenia

There is now compelling evidence that cannabis consumption might precipitate psychosis onset. The objective of the present study was to assess the role of individual sensitivity to the psychotogenic effect of cannabis in male patients with schizophrenia. The lifetime diagnosis, disease and substance-use history were determined using a standardized interview in 190 patients with schizophrenia. Of patients with lifetime cannabis use (n=121), 44 were characterized as Cannabis-sensitive (CS) patients if the onset of psychotic symptoms occurred within 1 month following the initiation of cannabis consumption, or following a marked rise of cannabis consumption, or marked aggravation of psychotic symptoms each time the subject used cannabis. Age at onset of psychosis was not different in patients with lifetime cannabis use compared to non-users. By contrast, the first psychotic episode occurred 2.6 yr earlier in CS compared to Non-cannabis-sensitive (NCS) patients (p=0.006). Moreover, a specific excess of family history of psychotic disorder was found in CS patients, but not of any other psychiatric disorder, as well as an earlier age at exposure to cannabis (16.7+/-2.5 yr, p=0.03). Sensitivity to psychotogenic effects of cannabis in schizophrenia patients could be related to both genetic vulnerability to schizophrenia and the influence of cannabis on brain maturation and could modulate the influence of cannabis on the onset of schizophrenia.

Reasons for cannabis use in men with and without psychosis

Psychoses are relatively low prevalence disorders that have a disproportionately negative impact on individuals and society. Cannabis use is one factor that can exacerbate the negative consequences associated with psychotic disorders. Relatively few studies have examined the effects or reasons for using cannabis self-reported by individuals with psychosis. The present study is the first known to compare directly such factors in individuals with and without psychosis, within a single study. At baseline and follow-up participants with psychosis most commonly reported using cannabis for positive mood alteration (36% and 42%), coping with negative affect (27% and 29%) and for social activity reasons (38% and 29%). The control group most commonly reported using cannabis for relaxation (34% and 43%) and social activity reasons (49% and 51%). Participants with psychosis were less likely to report relaxation as the most important effect after use (27%) or expect it at follow-up (49%) compared to the control group (53% and 70%). In both groups, addiction and positive affect enhancement were the composite variable scores correlated most consistently with concurrent amount and frequency of use.

Pharmacological treatment of schizophrenia and co-occurring substance use disorders

Substance abuse among individuals with schizophrenia is common and is often associated with poor clinical outcomes. Comprehensive, integrated pharmacological and psychosocial treatments have been shown to improve these outcomes. While a growing number of studies suggest that second-generation antipsychotic medications may have beneficial effects on the treatment of co-occurring substance use disorders, this review suggests that the literature is still in its infancy. Few existing well controlled trials support greater efficacy of second-generation antipsychotics compared with first-generation antipsychotics or any particular second-generation antipsychotic. This article focuses on and reviews studies involving US FDA-approved medications for co-occurring substance abuse problems among individuals with schizophrenia.Comprehensive treatment for individuals with schizophrenia and co-occurring substance use disorders must include specialized, integrated psychosocial intervention. Most approaches use some combination of cognitive-behavioural therapy, motivational enhancement therapy and assertive case management. The research on antipsychotic and other pharmacological treatments is also reviewed, as well as psychosocial treatments for individuals with schizophrenia and co-occurring substance use disorders, and clinical recommendations to optimize care for this population are offered.

Reasons for cannabis use: patients with schizophrenia versus matched healthy controls

OBJECTIVE

The aim of the present study was to compare self-reported reasons for cannabis use in patients with schizophrenia with those of matched healthy controls.

METHODS

Thirty-six stable outpatients with schizophrenia treated with atypical antipsychotics and 36 matched controls were included. They completed a questionnaire exploring 15 common reasons for use, established in other studies. results: Overall, patients more frequently agreed with the proposed reasons for use than controls. More specifically, patients with schizophrenia more often stated that they consumed cannabis to fight boredom and to ease social contacts.

CONCLUSIONS

Stable schizophrenia outpatients treated with atypicals do not use cannabis in order to reduce side-effects of medication or symptoms of their disorder. Rather, they used cannabis to overcome a feeling of social exclusion. Therefore, enhancing social participation of cannabis-using patients might be an effective strategy for reducing consumption.

Substance abuse and schizophrenia: pharmacotherapeutic intervention

Substance use disorder is common in patients with schizophrenia and dramatically worsens their outcome. The typical antipsychotic medications, introduced more than 50 years ago, are effective for the treatment of psychosis but may have only limited efficacy in patients with these co-occurring disorders because patients continue to use substances while taking them. In preliminary studies, however, several of the atypical antipsychotic medications have shown promise for reducing alcohol and drug use in patients with schizophrenia. A neurobiological formulation is discussed, suggesting that the use of substances in patients with schizophrenia may be based on a dysfunction within the dopamine-mediated brain reward circuitry and that clozapine, in particular, may potentially ameliorate this dysfunction and lessen the desire for substance use. Medications for the treatment of alcohol use disorders, such as disulfiram, naltrexone, and acamprosate, as well as other adjunctive medications, may also be useful. Further studies are required to establish a solid evidence base of best practices for the use of medications in these patients.

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.

Reasons for increased substance use in psychosis

Around half of all patients with schizophrenia are thought to abuse drugs or alcohol and there is good evidence to suggest that they have poorer outcomes than their non substance using counterparts. However, despite more than twenty years of research there is still no consensus on the aetiology of increased rates of substance use in people with psychosis. There is a clear need to understand the reasons for such high rates of substance use if treatments designed to help patients abstain from substance use are to be successful. This paper provides an update of the literature examining the reasons for substance use by people with psychosis, and includes a comprehensive review of the self report literature. The main theories as to why people with psychosis use substances are presented. There is evidence to suggest that cannabis may have a causal role in the development of psychopathology but not for other substances. The self report literature provides support for an 'alleviation of dysphoria' model of substance use but there is little empirical support for the self medication hypothesis, or for common factor models and bidirectional models of comorbidity. It is likely that there are multiple risk factors involved in substance use in psychosis and more work to develop and test multiple risk factor models is required.

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.

Long-acting injectable risperidone compared with zuclopenthixol in the treatment of schizophrenia with substance abuse comorbidity

OBJECTIVE

This study aimed to compare the efficacy of long-acting risperidone and zuclopenthixol in subjects with schizophrenia and substance abuse.

METHOD

A total of 115 subjects with schizophrenia and substance use disorders were enrolled for an open, randomized, controlled, 6-month follow-up study. Fifty-seven subjects were selected for treatment with long-acting injectable risperidone, while another 58 were treated with zuclopenthixol-depot.

RESULTS

Long-acting risperidone patients presented fewer positive urine tests (8.67 compared with 10.36, P = 0.005), showed improved scores on the Positive and Negative Syndrome Scale, and showed better compliance with the Substance Abuse Management program. The use of long-acting risperidone and less severe dependence explained the outcome at the end of the follow-up.

CONCLUSIONS

Long-acting injectable risperidone was more effective than zuclopenthixol-depot in improving substance abuse and schizophrenia symptoms in subjects with dual diagnosis.

Comorbid substance use and age at onset of schizophrenia

BACKGROUND

Substance use may be a risk factor for the onset of schizophrenia.

AIMS

To examine the association between substance use and age at onset in substance use and age at onset in a UK, inner-city sample of people with recent-onset schizophrenia.

METHOD

The study sample consisted of 152 people recruited to the West London First-Episode Schizophrenia Study. Self-reported data on drug and alcohol use, as well as information on age at onset of psychosis, were collected. Mental state, cognition (IQ, memory and executive function) and social function were also assessed.

RESULTS

In total, 60% of the participants were smokers, 27% reported a history of problems with alcohol use, 35% reported current substance use (not including alcohol), and 68% reported lifetime substance use (cannabis and psychostimulants were most commonly used). Cannabis use and gender had independent effects on age at onset of psychosis, after adjusting for alcohol misuse and use of other drugs.

CONCLUSIONS

The strong association between self-reported cannabis use and earlier onset of psychosis provides further evidence that schizophrenia may be precipitated by cannabis use and/or that the early onset of symptoms is a risk factor for cannabis use.

Treatment of substance use disorders in schizophrenia: a unifying neurobiological mechanism?

Substance use disorders (SUDs) are highly prevalent and are associated with poor outcomes among individuals with schizophrenia. Integrating treatments for both disorders improves outcomes. Numerous individual pharmacologic and psychosocial treatments have shown effectiveness at reducing substance use in individuals with a primary diagnosis of schizophrenia and co-occurring substance use disorders. Of these treatments, medications such as certain atypical antipsychotics and naltrexone, and psychosocial treatments such as contingency management, seem to be particularly promising. The development and evaluation of psychopharmacologic and psychosocial treatments for SUDs in schizophrenia would benefit from a better understanding of the neurobiological mechanisms underlying the effectiveness of such treatments. Several theories have been put forth to explain the heightened risk for SUDs in schizophrenia. Of these, brain reward circuitry dysfunction, hypothesized to be etiologically important in SUDs, may be an especially salient target for treatments aimed at the reduction of substance use in patients with schizophrenia. We review current pharmacologic and psychosocial treatments for SUDs in schizophrenia, and theoretical mechanisms underlying the increased risk for SUDs in this population. We propose that effective treatments may in part work through the modulation of brain reward circuitry dysfunction.

Comparisons between psychosis samples with different patterns of substance use recruited for clinical and epidemiological studies

Despite high rates of comorbid substance use disorders and smoking among people with psychotic disorders, previous studies have not examined differences in socio-demographic, clinical or disability characteristics between psychosis sub-groups with different patterns of substance use. This study compared the characteristics of five groups of people with psychosis and varying patterns of substance use (n=1152), including groups entering treatment studies for substance use or smoking, epidemiological samples of substance users and smokers, and people without such problems. Data were drawn from several recent Australian studies using comparable structured interviews and scales. There were moderate group differences in illness and symptom profiles, with substance users tending to have higher depression and reality distortion scores. Unexpectedly, personal disability was considerably lower among those seeking treatment for their substance use compared with the epidemiological groups, raising concerns about the appropriateness of traditional recruitment approaches in treatment studies and highlighting the need for more assertive treatment engagement and referral strategies in routine clinical settings. As a consequence of uncertainty about links between substance use and everyday functioning, it is suggested that health messages to young people may need to strike a better balance between the potential harms and benefits associated with substance use in pursuing broader harm minimization goals.

Delta-9-tetrahydrocannabinol effects in schizophrenia: implications for cognition, psychosis, and addiction

BACKGROUND

Recent advances in the neurobiology of cannabinoids have renewed interest in the association between cannabis and psychotic disorders.

METHODS

In a 3-day, double-blind, randomized, placebo-controlled study, the behavioral, cognitive, motor, and endocrine effects of 0 mg, 2.5 mg, and 5 mg intravenous Delta-9-tetrahydrocannabinol (Delta-9-THC) were characterized in 13 stable, antipsychotic-treated schizophrenia patients. These data were compared with effects in healthy subjects reported elsewhere.

RESULTS

Delta-9-tetrahydrocannabinol transiently increased 1) learning and recall deficits; 2) positive, negative, and general schizophrenia symptoms; 3) perceptual alterations; 4) akathisia, rigidity, and dyskinesia; 5) deficits in vigilance; and 6) plasma prolactin and cortisol. Schizophrenia patients were more vulnerable to Delta-9-THC effects on recall relative to control subjects. There were no serious short- or long-term adverse events associated with study participation.

CONCLUSIONS

Delta-9-tetrahydrocannabinol is associated with transient exacerbation in core psychotic and cognitive deficits in schizophrenia. These data do not provide a reason to explain why schizophrenia patients use or misuse cannabis. Furthermore, Delta-9-THC might differentially affect schizophrenia patients relative to control subjects. Finally, the enhanced sensitivity to the cognitive effects of Delta-9-THC warrants further study into whether brain cannabinoid receptor dysfunction contributes to the pathophysiology of the cognitive deficits associated with schizophrenia.

Substance Use Among Persons with Serious Mental Illness in Eastern Ontario

One hundred and eighty persons with serious mental illness (SMI) in eastern Ontario, receiving services from assertive community treatment teams in Brockville and Kingston were interviewed about substance use. Data were compared to survey findings for the Ontario population. Tobacco use was higher among both men and women in the SMI sample, but use of alcohol and drugs in the past 12 months was lower than population data. The frequency of alcohol use was significantly greater than drug use among the SMI sample.

A comparative study on schizophrenic patients with dual diagnosis

As indicated in the literature, substance abuse is a significant yet complex variable in schizophrenic disorder. We evaluated hospital charts of 86 schizophrenic patients with comorbid substance use disorder and of 56 patients suffering from schizophrenia-only. We surmised that among the former group there will be a substantial proportion of patients abusing opiates and that there will be differences between schizophrenic patients abusing different drugs. Both hypotheses could be confirmed. Among our dual patients, 18 patients with alcohol, 18 patients with cannabis, and 50 patients with "hard drugs" (opiates, cocaine) use disorder were identified and several significant differences were found between the individual groups of patients in respect to basic sociodemographic and clinical variables; in particular, schizophrenic patients with alcohol use disorder (and patients suffering from schizophrenia-only) were older and better socially adjusted than schizophrenic patients with "illegal" drug use disorder. The particularities of schizophrenic patients suffering from different kinds of substance use disorder should be considered when creating individualized therapeutic programs.

Substance abuse in schizophrenia: a review of the literature and a study of correlates in Sweden

The purpose of the current study is twofold: (a) to provide an overall synthesis of recent research on substance abuse in schizophrenia and (b) to present findings in a Swedish patient sample. Studies conducted since 1990 have found a wide range of abuse prevalence rates, with male gender and younger age as primary correlates. Less certainty exists regarding substance abuse as an independent risk factor for schizophrenia and its further impact on illness course. In a sample of 87 patients attending a psychiatric clinic in Malmö, lifetime prevalence of substance abuse was 48.3%, with abuse debut primarily preceding first contact for psychotic symptoms. Significant correlates of abuse were male gender, family history of substance abuse, and increased rates of hospitalization and criminality, with poorer outcome found in previous as well as current abusers. Alcohol abuse, either solely or in combination with other substances, was the main type of substance abuse. Although the specific factors (social, behavioural, genetic) that predispose schizophrenic patients to substance abuse remain unclear, the predominantly male profile of abusers might suggest a link between substance abuse and the poorer clinical outcome frequently observed, especially in male schizophrenic patients.

Social functioning, psychopathology, and medication side effects in relation to substance use and abuse in schizophrenia

OBJECTIVE

To identify correlates of self-reported substance use and problems associated with that use in people with schizophrenia.

METHODS

A sample of 404 patients with schizophrenia, schizoaffective disorder, or schizophreniform disorder and longitudinal assessments of substance use were examined. Three groups were formed according to consistency of substance use over time: No/Low Alcohol, Alcohol Only, and Drug Use (with or without alcohol use). Similar groups were formed regarding problems associated with alcohol use. Groups were compared on demographics, psychiatric history, psychopathology, medication side effects, and social functioning.

RESULTS

Substance users were more likely to be young, male, and to have lower levels of education. Substance users generally had fewer negative symptoms, more social contacts, and better social-leisure functioning. However, substance users, especially drug users, also were rated as having more interpersonal and family problems, had an earlier age at first psychiatric hospitalization, and were more likely to have been recently hospitalized. Patients reporting problems with alcohol use reported more frequent alcohol and drug use, greater severity of akathisia, and problems in interpersonal, family, and self-efficacy domains.

CONCLUSIONS

Many of the same variables that correlate with substance use disorder also correlated with moderate substance use in this sample of people with schizophrenia. Although moderate users of alcohol and drugs may have better social functioning in some areas, they also are likely to have substantial problems in interpersonal relationships, especially those involving family members.

Chronically mentally ill patients with and without substance use disorders: a pilot study

The study was designed to assess characteristics of chronic mentally ill patients with and without a substance use disorder. Study patients (n=48) had either psychiatric illness alone (they received conventional psychiatric rehabilitation) or dual diagnoses (they received mental illness and substance abuse services). All patients were administered the Brief Symptom Inventory (BSI), the Client Satisfaction Questionnaire, the Perceived Social Support Scales, and the Composite International Diagnostic Interview. Higher proportions of dually diagnosed patients had schizophrenia, had higher scores on the BSI, and were less satisfied with treatment.

Addiction and schizophrenia

Epidemiologic studies in the general population and those based on the clinical assessment of schizophrenic populations have revealed a high degree of overlap between schizophrenia and addictive disorders. The abuse of psychoactive substances (including alcohol) throughout life is so frequent (50%) that the possibility of a specific link inevitably arises. Various hypotheses have been suggested to explain the high co-morbidity between schizophrenia and addiction: 1) The social-environmental hypothesis has been developed but studies have provided poor evidence to validate it. 2) The possible shared biological vulnerability between schizophrenia and addictions led researchers to explore common genetic determinants and study the involvement of the dopaminergic and opioid systems in the aetiology of both schizophrenia and the abuse of and dependence on psychoactive drugs. 3) Finally, the theory of self-medication suggests that schizophrenics may be attempting to counter the deficit linked to their disorders by using the substances they take or their dependency-type behaviour to cope with their emotional problems. The clinical profile of schizophrenic addicts does seem to display some distinctive features, such as the high level of depressive co-morbidity, very high nicotine and alcohol dependence, with a very poor prognosis. These patients are difficult to manage; the possibility of pharmacologic interactions between the substances they are taking and neuroleptic medication calls for prudence, and their compliance is also poor. Addictive disorders in schizophrenics are currently a topic of active research intended to lead to identifying specific treatments. The early identification of addictive disorders in schizophrenics should make it possible to limit their development and improve the prognosis.

Cost-effectiveness of mental health services for persons with a dual diagnosis: a literature review and the CCMHCP. The Cost-Effectiveness of Community Mental Health Care for Single and Dually Diagnosed Project

People suffering from comorbid mental illness and substance abuse disorders (the dually diagnosed) are thought to constitute large portions of clients treated as outpatients by public-sector community-based mental health providers. These providers dispense units of ambulatory mental health services and treatments incrementally to maintain clients in the community and out of psychiatric hospitals. Community maintenance is one step, albeit critical, toward quitting drugs and eventual abstinence. Thus, there is a need for information that compares the effectiveness and cost of such services on dually diagnosed clients to identify appropriate low-cost high-yield treatment and service options and packages. This article provides a review of the literature on the effectiveness of ambulatory mental health services and recent emergent reports of cost-effectiveness of programs for the dually diagnosed, paying special attention to the gray areas and gaps. This article also describes a new project; an inexpensive add-on to an existing community mental health center. The project will be examining over 4 years of data to compare influence and cost of different ambulatory mental health services and treatments delivered to a matched pair group of clients with dual disorders and those with only mental illness. The intention of this project is not only to address gray areas and gaps in the literature, but also to inform a more rational deployment of mental health services.

Toward a rational pharmacotherapy of comorbid substance abuse in schizophrenic patients

The prevalence of substance abuse is elevated among schizophrenic patients. When free of illicit substances and sober, substance-abusing schizophrenic patients may have a better prognosis than other frequently hospitalized schizophrenic patients. However, the cost of substance abuse is great in terms of rehospitalization, homelessness, risk of other medical illness, disruption of social and vocational function, exacerbation of symptoms, suicide, and increased health care expenses. Important recent developments in medications for reducing substance abuse in nonschizophrenic populations make it timely to consider factors that might contribute to substance abuse among schizophrenic patients. This review will focus on substances most frequently abused by schizophrenic patients: nicotine, alcohol, cannabis, and psychostimulants. It concentrates on two conceptual foci: "self-medication hypotheses" and "comorbid addiction vulnerability hypotheses". The relationship between these hypotheses and possible pharmacotherapeutic approaches for substance-abusing schizophrenic patients will be considered.

A review of comorbidity: major mental illness and problematic substance use

OBJECTIVE

The aim of this paper is to critically review the literature on major mental illness and problematic substance use in order to provide clinicians and policy-makers with evidence to support proposed directions for management of the above.

METHOD

The available literature was accessed using computerised databases and manual searching.

RESULTS

The predominantly North American-based literature is largely descriptive. Those studies which attempt empirical evaluation are limited by methodological weaknesses which include small sample sizes, short follow-up periods, inadequate measurement of substance use, lack of experimental design, and treatment drift over time. However, there is consensus among most studies regarding prevalence rates and treatment.

CONCLUSIONS

Problematic substance use is the most common comorbid condition among people with a major mental illness and is associated with poorer patient outcomes. There is evidence to suggest that the integration of mental health and drug and alcohol services will result in improved detection, assessment and management of comorbidity. Integration refers to the provision of comprehensive services by a single service with staff who are competent in both mental health and drug and alcohol skills. A tolerant, non-confrontational approach to substance use is most appropriate for people with a major mental illness. Treatment programs need to recognise the longitudinal nature of substance abuse and dependence. More research needs to be conducted in this field in order to establish guidelines for effective management.

Complications of severe mental illness related to alcohol and drug use disorders

In this chapter we review research on the relationships between substance use disorder and 11 domains of adjustment for people with severe mental illness. Studies are divided into correlational research and prospective, longitudinal research, with greater weight given to those in the latter category. The weight of the evidence indicates that substance abuse severely complicates severe mental illness in the following domains: relapse of psychiatric illness, hospitalization, disruptive behavior, familial problems, residential instability, decreased functional status, HIV infection, and medication noncompliance. We discuss the limits of causal inference in these studies and the possible mechanisms that relate substance abuse to various complications.