Clozapine for comorbid substance use disorder and schizophrenia: do patients with schizophrenia have a reward-deficiency syndrome that can be ameliorated by clozapine?

A randomized trial of clozapine vs. other antipsychotics for cannabis use disorder in patients with schizophrenia

OBJECTIVE

Cannabis use disorder is the most common co-occurring drug use disorder in people with schizophrenia and is associated with poor outcomes. We launched a randomized controlled trial to assess the impact of clozapine compared with treatment as usual on cannabis use in patients with schizophrenia and co-occurring cannabis use disorder.

METHODS

Thirty-one patients with schizophrenia and co-occurring cannabis use disorder were randomly assigned to switch to clozapine or to stay on their current antipsychotic and were then followed weekly for 12 weeks. Blinded raters assessed participants weekly with the Timeline Follow-back for substance use and the expanded Brief Psychiatric Rating Scale for symptoms. Longitudinal random effects models were used to investigate the time-varying differences in cannabis use and other outcomes between the treatment as usual and clozapine groups.

RESULTS

The two groups differed in average intensity of cannabis use by approximately 4.5 joints/week, with lesser use in the clozapine group (t = -1.77; df = 28.5; p=.086; effect size ~ 0.6). Symptoms and functioning were not different between the two groups.

CONCLUSIONS

Clozapine may reduce cannabis use among patients with schizophrenia and co-occurring cannabis use disorder. Further controlled trials are warranted.

Treating comorbid substance use disorders in schizophrenia

AIM

To review the literature on pharmacological and psychosocial treatment approaches for people with schizophrenia and comorbid substance use disorder(s) (SUD).

METHOD

Selective literature review.

RESULTS

Despite the high prevalence of comorbid SUD among people with schizophrenia, there is a considerable paucity of rigorously conducted randomized controlled treatment trials. While there is some evidence for clozapine, and for the adjunctive use of agents such as naltrexone for comorbid alcohol dependence, the available literature largely comprises case studies, case series, open label studies and retrospective surveys. In terms of psychosocial approaches, there is reasonable consensus that integrated approaches are most appropriate. Regarding specific aspects of care, motivational interviewing, cognitive behavioural therapy and contingency management have an emerging supportive literature, as do family interventions. However, there is no 'one size fits all', and a flexible approach with the ability to apply specific components of care to particular individuals, is required. Group-based therapies and longer-term residential services have an important role for some patients, but further research is required to delineate more clearly which patients will benefit from these strategies.

CONCLUSIONS

While there is growing (albeit limited) evidence that integrated and well articulated interventions that encompass pharmacological and psychosocial parameters can be beneficial for people with schizophrenia and comorbid SUD, there remains a considerable gap in the literature available to inform evidence-based practice.

Neuromodulation of decision-making in the addictive brain

Noninvasive brain stimulation of the dorsolateral prefrontal cortex with repetitive transcranial magnetic stimulation and transcranial direct current stimulation can modify decision-making behaviors in healthy subjects. The same type of noninvasive brain stimulation can suppress drug craving in substance user patients, who often display impaired decision-making behaviors. We discuss the implications of these studies for the cognitive neurosciences and their translational applications to the treatment of addictions. We propose a neurocognitive model that can account for our findings and suggests a promising therapeutic role of brain stimulation in the treatment of substance abuse and addictive behavior disorders.

Role of caloric homeostasis and reward in alcohol intake in Syrian golden hamsters

The Syrian golden hamster drinks alcohol readily, but only achieves moderate blood alcohol levels, and does not go through withdrawal from alcohol. Because the hamster is a model of caloric homeostasis, both caloric content and reward value may contribute to the hamster's alcohol consumption. The current study examines alcohol consumption in the hamster when a caloric or non-caloric sweet solution is concurrently available and caloric intake in the hamster before, during, and after exposure to either: alcohol, sucrose or saccharin. In Experiments 1 and 2, hamsters were given access to alcohol (15% v/v) and water; once alcohol consumption steadied, a bottle containing an ascending concentration of sucrose (99-614 mM) or saccharin (2-10 mM), or water was added. In Experiment 3, hamsters were given access to alcohol (15% v/v), sucrose (614 mM), saccharin (4 mM), or a second water bottle for 14 days. After the second bottle was removed, measurements continued for 14days. Sucrose exposure suppressed alcohol consumption at concentrations lower in calories than the alcohol solution. Saccharin exposure failed to suppress alcohol consumption. Exposure to sucrose and alcohol but not saccharin decreased food intake. Decreased alcohol consumption in response to a caloric sweetener and decreased food intake during alcohol exposure support that alcohol consumption by the hamster is mediated by caloric content. However, suppression of alcohol intake by a sucrose solution of lower caloric content and the equivalent intake of individual alcohol, sucrose and saccharin solutions support a role for reward value in alcohol consumption.

Deep brain stimulation of the nucleus accumbens reduces alcohol intake in alcohol-preferring rats

Object

The authors tested the hypothesis that deep brain stimulation (DBS) in the nucleus accumbens (NAcc) decreases alcohol intake in alcohol-preferring (P) rats after each animal has established a stable, large alcohol intake and after P rats with an established intake have been deprived of alcohol for 4–6 weeks.

Methods

Bipolar stimulating electrodes were bilaterally placed in the NAcc using stereotactic coordinates. In the first study, P rats (9 animals) were allowed to establish a stable pattern of alcohol intake (about 5–7 g/day) over approximately 2 weeks, and the acute effects of DBS in the NAcc (140–150 Hz, 60-μsec pulse width, and 200-μA current intensity) on alcohol intake and alcohol preference were studied. Each animal acted as its own control and received 1 hour of DBS followed by 1 hour of sham-DBS or vice versa on each of 2 sequential days. The order of testing (sham-DBS vs DBS) was randomized. In the second study, each animal was allowed to establish a stable alcohol intake and then the animal was deprived of alcohol for 4–6 weeks. Animals received DBS (6 rats) or sham-DBS (5 rats) in the NAcc for 24 hours starting when alcohol was reintroduced to each animal.

Results

Deep brain stimulation in the NAcc, as compared with a period of sham-DBS treatment in the same animals, acutely decreased alcohol preference. Furthermore, alcohol consumption and preference were significantly reduced in the DBS group compared with the sham treatment group during the first 24 hours that alcohol was made available after a period of forced abstinence.

Conclusions

The NAcc plays a key role in the rewarding and subsequent addictive properties of drugs of abuse in general and of alcohol in particular. Deep brain stimulation in the NAcc reduced alcohol consumption in P rats both acutely and after a period of alcohol deprivation. Therefore, DBS in the NAcc coupled with other neurophysiological measurements may be a useful tool in determining the role of the NAcc in the mesocorticolimbic reward circuit. Deep brain stimulation in the NAcc may also be an effective treatment for reducing alcohol consumption in patients who abuse alcohol and have not responded to other forms of therapy.

Clozapine chronically suppresses alcohol drinking in Syrian golden hamsters

Alcohol use disorder is common in patients with schizophrenia and is associated with poor clinical outcomes. Preliminary reports from our group and others suggest that the atypical antipsychotic clozapine may decrease alcohol use in these patients. We have previously shown that clozapine suppresses alcohol consumption for 9 days in Syrian golden hamsters. Here, we assessed the effects of clozapine on alcohol consumption in hamsters over a 27-day period, using a continuous access, 2-bottle (15% alcohol vs. water) protocol. Clozapine (4, 8, or 12 mg/kg/day, injected subcutaneously [s.c.]) dose-dependently suppressed alcohol drinking, while increasing food and water intake. There was no tolerance within individual groups to the effect of clozapine on alcohol drinking over time. In a separate experiment, the effects of clozapine on sucrose and water drinking and food intake over a 9-day period were assessed. Clozapine (4, 8, or 12 mg/kg/day s.c.) failed to suppress sucrose (0.09 M), food, or water consumption at any time-point tested. In a related study, assessment of blood alcohol levels in hamsters indicated that blood alcohol levels were maintained within a narrow and moderate range (7-13 mg/dL), levels noted by others to produce physiologic effects in rodents. The ability of clozapine to suppress alcohol drinking in the hamster over an extended period of time without suppressing sucrose, water, or food consumption is consistent with preliminary reports indicating that clozapine limits frequent alcohol use, even producing abstinence in many patients with schizophrenia.

Management of schizophrenia with substance use disorders

Around 50% of patients with schizophrenia develop a co-occurring substance use disorder involving alcohol or illicit substances at some time during their lives. The comorbid substance abuse will markedly affect the course of illness of schizophrenia. In this article, the authors review the epidemiology, theories of causation, effect on the course of illness, and treatment of co-occurring schizophrenia and substance use disorder.

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.

Comorbid psychiatric and substance abuse disorders: recent treatment research

Psychiatric comorbidity is defined as the co-occurrence of a psychiatric disorder in a patient with a substance use disorder. Psychiatric disorders in substance abuse patients can antedate the substance use disorder or be a consequence of the substance abuse. There is emerging evidence that drug use in adolescence may alter the onset of certain psychiatric disorders in vulnerable individuals. Patients with concurrent comorbid disorders present special challenges for the substance abuse treatment system in terms of diagnosis and management because each disorder has the capability of exacerbating the other. This manuscript is a summary of an ISAM symposium that featured three speakers who discussed the following topics: 1. Etiology and treatment of comorbid psychiatric and substance use disorders in adolescents; 2. Treatment of ADHD and substance use disorders in adults; 3. Effects of substance abuse on the onset, severity, and treatment of schizophrenia. Recommendations for further research will be presented.

Activation instead of blocking mesolimbic dopaminergic reward circuitry is a preferred modality in the long term treatment of reward deficiency syndrome (RDS): a commentary

Background and hypothesis

Based on neurochemical and genetic evidence, we suggest that both prevention and treatment of multiple addictions, such as dependence to alcohol, nicotine and glucose, should involve a biphasic approach. Thus, acute treatment should consist of preferential blocking of postsynaptic Nucleus Accumbens (NAc) dopamine receptors (D1-D5), whereas long term activation of the mesolimbic dopaminergic system should involve activation and/or release of Dopamine (DA) at the NAc site. Failure to do so will result in abnormal mood, behavior and potential suicide ideation. Individuals possessing a paucity of serotonergic and/or dopaminergic receptors, and an increased rate of synaptic DA catabolism due to high catabolic genotype of the COMT gene, are predisposed to self-medicating any substance or behavior that will activate DA release, including alcohol, opiates, psychostimulants, nicotine, gambling, sex, and even excessive internet gaming. Acute utilization of these substances and/or stimulatory behaviors induces a feeling of well being. Unfortunately, sustained and prolonged abuse leads to a toxic" pseudo feeling" of well being resulting in tolerance and disease or discomfort. Thus, a reduced number of DA receptors, due to carrying the DRD2 A1 allelic genotype, results in excessive craving behavior; whereas a normal or sufficient amount of DA receptors results in low craving behavior. In terms of preventing substance abuse, one goal would be to induce a proliferation of DA D2 receptors in genetically prone individuals. While in vivo experiments using a typical D2 receptor agonist induce down regulation, experiments in vitro have shown that constant stimulation of the DA receptor system via a known D2 agonist results in significant proliferation of D2 receptors in spite of genetic antecedents. In essence, D2 receptor stimulation signals negative feedback mechanisms in the mesolimbic system to induce mRNA expression causing proliferation of D2 receptors.

Proposal and conclusion

The authors propose that D2 receptor stimulation can be accomplished via the use of Synapatmine™, a natural but therapeutic nutraceutical formulation that potentially induces DA release, causing the same induction of D2-directed mRNA and thus proliferation of D2 receptors in the human. This proliferation of D2 receptors in turn will induce the attenuation of craving behavior. In fact as mentioned earlier, this model has been proven in research showing DNA-directed compensatory overexpression (a form of gene therapy) of the DRD2 receptors, resulting in a significant reduction in alcohol craving behavior in alcohol preferring rodents. Utilizing natural dopaminergic repletion therapy to promote long term dopaminergic activation will ultimately lead to a common, safe and effective modality to treat Reward Deficiency Syndrome (RDS) behaviors including Substance Use Disorders (SUD), Attention Deficit Hyperactivity Disorder (ADHD), Obesity and other reward deficient aberrant behaviors. This concept is further supported by the more comprehensive understanding of the role of dopamine in the NAc as a "wanting" messenger in the meso-limbic DA system.

Negative symptoms are associated with less alcohol use, craving, and "high" in alcohol dependent patients with schizophrenia

BACKGROUND

Alcohol use disorders (AUDs) frequently co-occur with and exacerbate schizophrenia, yet the specific relationships between schizophrenia symptoms and alcohol use remain unclear.

METHODS

PANSS scores were correlated with measures of alcohol and other substance use in patients with schizophrenia-spectrum disorders and AUDs entering a trial of monitored naltrexone treatment. Data were analyzed from the first 80 participants; 55% had schizophrenia and 45% had schizoaffective disorder. All had AUDs; 95% had alcohol dependence and 5% alcohol abuse; 34% also had cannabis abuse/dependence and 31% cocaine abuse/dependence.

RESULTS

PANSS Negative scores were inversely correlated with Addiction Severity Index alcohol composite scores, alcohol craving, quality of alcohol "high" (euphoria), and with frequency of cannabis use. An exploratory analysis indicated that the negative symptoms that may most strongly correlate with less alcohol use, craving and/or euphoria were passive/apathetic social withdrawal, blunted affect, difficulty in abstract thinking, and stereotyped thinking. Higher PANSS Composite scores, indicating the predominance of positive over negative PANSS symptoms, correlated with more alcohol craving and cannabis use. Higher PANSS General scores were associated with more alcohol craving.

CONCLUSIONS

These findings extend previous reports of the association of negative schizophrenia symptoms with less alcohol and substance use to patients with AUDs and indicate that this relationship also includes less alcohol craving and less alcohol euphoria. The findings may also provide some initial evidence that specific negative symptoms may be keys to these relationships.

Quetiapine decreases alcohol consumption, craving, and psychiatric symptoms in dually diagnosed alcoholics

AIMS

Patients with dual diagnosis are often excluded from clinical trials although more than half of all individuals with Bipolar Disorder have a substance abuse problem at some point in their lifetime, representing a high-risk clinical population. The purpose of this study was to investigate the safety and efficacy of quetiapine in the treatment of alcohol dependence comorbid with disorders characterized by high levels of mood and behavioral instability.

METHODS

Twenty-eight subjects, after a detoxification period, were orally treated with flexible doses of quetiapine for 16 weeks. At each assessment patients were evaluated through the Obsessive Compulsive Drinking Scale (OCDS), the Visual Analogue Scale (VAS) for craving, the Clinical Institute Withdrawal Assessment for Alcohol (CIWA-Ar), the Brief Psychiatric Rating Scale (BPRS), the Hamilton Depression Rating Scale (HDRS), the Young Mania Rating Scale (YMRS), and the Clinical Global Impression (CGI) scale.

RESULTS

Forty-three percent of patients remained totally alcohol free, 32% patients relapsed, with an average of 15.4 drinking days in the period of the study (112 days) and 25% dropped-out. Significant reductions from baseline to exit were observed in the OCDS, VAS, BPRS, HDRS, and number of drinking days per week. Changes in alcohol craving correlated with psychiatric symptoms as to BPRS and HDRS, with the highest level of correlation evidenced for the HDRS items of insomnia.

DISCUSSION

In this open-label study, quetiapine decreased alcohol consumption, craving for alcohol, and psychiatric symptoms intensity, maintaining a good level of tolerance. A strength of this study is that the use of quetiapine was not adjunctive with other pharmacological and non-pharmacological treatment. Double-blind placebo-controlled studies are required with a larger study population to confirm these data. In the meantime, for a select group of psychiatric patients, quetiapine may offer some advantages in preventing relapse.

Effect of olanzapine and risperidone on subjective well-being and craving for cannabis in patients with schizophrenia or related disorders: a double-blind randomized controlled trial

OBJECTIVE

To examine whether subjective well-being and craving for cannabis were different in patients with schizophrenia or related disorders treated with either olanzapine or risperidone.

METHOD

A 6-week, double-blind, randomized trial of olanzapine and risperidone was carried out in 128 young adults with recent onset schizophrenia or related disorders. Primary efficacy measures were the mean baseline-to-endpoint change in total scores on the Subjective Well-Being under Neuroleptics scale, the Obsessive-Compulsive Drug Use Scale, the Drug Desire Questionnaire, and the cannabis use self-report. An analysis of covariance was used to test between-group differences.

RESULTS

Estimated D(2) receptor occupancy did not differ between olanzapine (n = 63) and risperidone (n = 65). Similar improvements in subjective well-being were found in both groups. In the comorbid cannabis-using group (n = 41, 32%), a similar decrease in craving for cannabis was found in both treatment conditions.

CONCLUSIONS

Both olanzapine and risperidone were associated with improved subjective well-being. No evidence was found for a differential effect of olanzapine or risperidone on subjective experience or on craving for cannabis in dosages leading to comparable dopamine D(2) occupancy.

CLINICAL TRIAL REGISTRATION NUMBER

ISRCTN46365995.

Time to rehospitalization of clozapine versus risperidone in the naturalistic treatment of comorbid alcohol use disorder and schizophrenia

Clozapine is known to be effective in treating schizophrenia patients with comorbid alcohol use disorders (AUD). However, few prospective studies have examined the effect of clozapine on community survival of the patient, which is one of the most important indicators of success for patients with schizophrenia. In this prospective, naturalistic, observational, community-survival-analysis study, we compared the effect of clozapine and risperidone on two-year psychiatric hospitalization rate and time to hospitalization in the treatment of patients with schizophrenia and comorbid AUD. We found that the clozapine treated patients were readmitted to hospital significantly later (mean survival=526.5 days, n=25 patients) than the risperidone treated patients (mean survival=420.4 days, n=36 patients). The survival curve for the clozapine-treated patients was significantly different from that of the risperidone treated patients (log-rank test, df=1, p=.045). At the end of the two-year study period, 75% of the risperidone treated patients had been admitted to the hospital, compared to only 48% of the clozapine treated patients. These findings suggest that clozapine should be considered for the treatment of schizophrenia patients with comorbid AUD. However, due to the limitations of this study, further studies will be required to confirm these findings.

The effectiveness of antipsychotic medications in patients who use or avoid illicit substances: results from the CATIE study

OBJECTIVE

This double-blind study compared a second generation (atypical) antipsychotic drugs compared to a representative older agent for patients with schizophrenia who use or avoid illicit substances.

METHODS

Schizophrenic subjects were recruited at 57 U.S. sites and randomly assigned to olanzapine, perphenazine, quetiapine, risperidone or ziprasidone for up to 18 months. The primary aim of this analysis was to delineate differences between the overall effectiveness of these five treatments among patients who used or did not use illicit substances.

RESULTS

There were no significant differences between treatment groups in time to all-cause treatment discontinuation among patients who use illicit drugs (median 3.3 to 6.8 months). Among non-users time to treatment discontinuation was significantly longer for patients treated with olanzapine (median 13.0 months) than perphenazine ( 5.9 months), risperidone (5.6 months), or quetiapine (5.0 months); time to discontinuation for ziprasidone (4.3 months) was even shorter, although the latter difference was not significant. The difference between risperidone and quetiapine, although small, was significant. All remaining differences were non-significant. Similar results were found for discontinuation due to inefficacy. There were no differences between illicit users and non-users in symptom reduction and global improvement, after adjustment for differential duration of treatment. Differences in discontinuation results were attenuated by non-compliance, but the trends persisted after controlling for treatment compliance.

CONCLUSIONS

Among patients with chronic schizophrenia who avoid use of illicit drugs, olanzapine was more effective than other antipsychotics as reflected by longer time to all-cause discontinuation, but illicit substance abuse attenuated this advantage, reinforcing the need for concurrent substance abuse treatment.

Prefrontal cortex modulation using transcranial DC stimulation reduces alcohol craving: a double-blind, sham-controlled study

BACKGROUND

Functional neuroimaging studies have shown that specific brain areas are associated with alcohol craving including the dorsolateral prefrontal cortex (DLPFC). We tested whether modulation of DLPFC using transcranial direct current stimulation (tDCS) could alter alcohol craving in patients with alcohol dependence while being exposed to alcohol cues.

METHODS

We performed a randomized sham-controlled study in which 13 subjects received sham and active bilateral tDCS delivered to DLPFC (anodal left/cathodal right and anodal right/cathodal left). For sham stimulation, the electrodes were placed at the same positions as in active stimulation; however, the stimulator was turned off after 30s of stimulation. Subjects were presented videos depicting alcohol consumption to increase alcohol craving.

RESULTS

Our results showed that both anodal left/cathodal right and anodal right/cathodal left significantly decreased alcohol craving compared to sham stimulation (p<0.0001). In addition, we found that following treatment, craving could not be further increased by alcohol cues.

CONCLUSIONS

Our findings showed that tDCS treatment to DLPFC can reduce alcohol craving. These findings extend the results of previous studies using noninvasive brain stimulation to reduce craving in humans. Given the relatively rapid suppressive effect of tDCS and the highly fluctuating nature of alcohol craving, this technique may prove to be a valuable treatment strategy within the clinical setting.

Effectiveness of atypical antipsychotics for substance use in schizophrenia patients

OBJECTIVE

This study examined the influence of medication class (atypical antipsychotic, typical antipsychotic and no medication) and compliance on substance use outcomes for schizophrenia patients in the community.

METHOD

N=362 adults with schizophrenia-spectrum disorder were followed for 3 years in a naturalistic study with structured interviews at 6-month intervals. Multivariable time-series analysis was performed using propensity-score adjustment for selection to medication class.

RESULTS

Participants who were compliant with atypical antipsychotic medications for 90 days or more during each 6-month period were significantly less likely to use substances during the next 6-month period than patients who were compliant with typical antipsychotics or those who were not prescribed either type of medication for at least 90 days.

CONCLUSION

Atypical antipsychotics may offer an advantage in reducing substance use among schizophrenia patients. For patients to benefit from atypical antipsychotics, treatment should focus on enhancing compliance and integrating substance use treatment.

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.

Combination of Olanzapine With Opioid-Agonists in the Treatment of Heroin-Addicted Patients Affected by Comorbid Schizophrenia Spectrum Disorders

The objective of this study was to evaluate the efficacy of olanzapine (OLA) in heroin-dependent patients affected by comorbid schizophrenia spectrum disorders (SSD). Sixty-one patients who met the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for heroin dependence and the criteria for SSD (schizophrenia and schizotypal and schizoaffective-bipolar disorders) were treated in a 12-week prospective observational trial of substitution treatment in combination with OLA or typical antipsychotic haloperidol. Patients were included into 2 subgroups, in relationship with treatment, for the evaluation of the end points at week 12: group 1, SSD treated with OLA (35 patients); group 2, SSD treated with haloperidol (26 patients). Efficacy measures were retention in treatment, Symptoms Checklist-90 score changes, negative urinalyses results, and craving reduction. The rate of patients who remained in treatment at week 12 in group 1 SSD, treated with OLA, was significantly higher (32[91.4%]) than that of group 2 SSD (13 [50%]), treated with the typical antipsychotic (P < 0.001). The decrease in Symptoms Checklist-90 total scores from baseline, as expression of an improvement in comorbid psychopathology in the patients who completed the treatment, was significantly more consistent in group 1 than in group 2 patients (P < 0.01). Among the patients who remained in treatment, 64.4% achieved early full substance abuse remission, whereas 35.6% achieved partial substance abuse remission, with a significant difference between 1 (78.13%) and 2 (46.1%) treatment subgroups (P = 0.04). Although obtained by an observational-open clinical study with multiple limitations, our findings suggest that OLA may be able to increase retention and negative urinalyses rates during opioid agonist maintenance treatment in the patients with SSD and to improve psychopathology symptoms and tolerability in these dually diagnosed heroin addicts. Preliminary accurate diagnostic assessment and appropriate psychoactive medication in addicted patients affected by schizophrenia and schizotypal and schizoaffective-bipolar disorders seem to obtain less adverse effects and a more successful outcome of drug dependence treatment.

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.

Gene \Narcotic Attenuation Program attenuates substance use disorder, a clinical subtype of reward deficiency syndrome

This study evaluated the effects of a putative activator of brain reward circuitry on outcomes in a 1-y prospective comprehensive outpatient clinical program. As part of the Gene Narcotic Attenuation Program, Haveos (Synaptamine)(TM) was administered for the treatment of substance use disorder. Seventy-six patients (45 males and 31 females; mean age, 33 y [standard deviation, 7.0]) who had been given a diagnosis of serious substance use disorder were recruited. After exclusion of 15 patients who dropped out before the end of the study, self-reported craving decreased from program entrance to 12 wk (visual analog scale whereby 0 represents no craving and 5, the strongest craving) for 61 compliant patients (mean decrease, 2.85, 95% confidence interval [CI], 2.65, 3.05); this improvement was significant (P<.001). Building up to relapse scores (each of 5 individual items and summary value) showed similar improvement after 1 y of treatment; the mean decrease in scores was significant for stress (t=3.3; P=.002), depression (t=4.0; P<.001), anger (t=4.4; P<.001), anxiety (t=4.5, P<.001), drug craving (t=5.4, P<.001), and summary building up to relapse (t=4.1; P<.001). Also, recovery score measures of energy level (t=8.4; P<.001) and ability to refrain from drug-seeking behavior (t=7.4; P<.001) showed significant mean increases from entry to 1 y. During the study, the alcoholic dropout rate was only 7% (4 of 57), which was significantly (Fisher's exact test, P<.001) lower than the 73% (11 of 15) dropout rate reported for psychostimulant users. Although these results are significant, any interpretation must await the performance of rigorous double-blind studies.

Pharmacotherapy for schizophrenia and co-occurring substance use disorders

Substance use disorder (SUD) occurs commonly in patients with schizophrenia and is associated with a poor outcome. Despite this common co-morbid occurrence (and its negative impact on the course of schizophrenia), there have been very few studies assessing pharmacological strategies for optimal treatment of these patients. A number of theories have been advanced to help explain the high rate of substance use disorder in patients with schizophrenia. Our group has suggested that the brain reward circuit dysfunction model, which may incorporate aspects of all of these models, may help direct research aimed at developing new pharmacological treatments for patients with schizophrenia and co-occurring SUD. Although typical antipsychotic medications appear to be of limited value in these patients, emerging, but preliminary, data suggest that the atypical antipsychotics, particularly clozapine, may be particularly helpful. The role of adjunctive medications, such as those medications that have recently been shown to be useful for the treatment of alcoholism, may have a role in the treatment of these patients, although only naltrexone has, thusfar, been carefully tested in these comorbid patients. Further studies are indicated to assess the role of novel pharmacologic treatment strategies for these patients. Ultimately, any medication given to these patients will need to be prescribed within psychosocial treatment programs aimed at assisting these patients in limiting and ultimately ceasing substance use.

Antipsychotic drug treatment of schizophrenic patients with substance abuse disorders

BACKGROUND/AIM

In recent years, there has been a growing interest in developing adequate treatments for patients with a diagnosis of schizophrenia and a comorbid substance use disorder (SUD). In the present paper we aim to critically review published reports on the use of conventional and second-generation antipsychotics in the treatment of patients with schizophrenia and comorbid SUD, to provide clinicians with a clearer view of the pharmacological treatment of this highly prevalent dual diagnosis based upon the evidence arising from the scientific literature.

METHODS

A search of the relevant literature from Medline, PsycLIT and EMBASE databases, included in the Science Citation Index, and available up to November 2006 was conducted using the terms: 'schizophrenia', 'substance use disorder' and 'antipsychotics'.

RESULTS

While research on the use of conventional antipsychotics has remained limited, the majority of studies suggest the effectiveness of second-generation antipsychotics, particularly clozapine, for patients with schizophrenia and a comorbid substance use disorder.

CONCLUSION

In the absence of randomized controlled trials that could provide more reliable information, clinical decisions may need to rely on indirect data provided by the increasing number of case reports, open trials and retrospective studies showing a decrease in cigarette smoking, alcohol, cocaine or cannabis use and an improvement of overall psychiatric symptoms.

Food intake and reward mechanisms in patients with schizophrenia: implications for metabolic disturbances and treatment with second-generation antipsychotic agents

Obesity is highly prevalent among patients with schizophrenia and is associated with detrimental health consequences. Although excessive consumption of fast food and pharmacotherapy with such second-generation antipsychotic agents (SGAs) as clozapine and olanzapine has been implicated in the schizophrenia/obesity comorbidity, the pathophysiology of this link remains unclear. Here, we propose a mechanism based on brain reward function, a relevant etiologic factor in both schizophrenia and overeating. A comprehensive literature search on neurobiology of schizophrenia and of eating behavior was performed. The collected articles were critically reviewed and relevant data were extracted and summarized within four key areas: (1) energy homeostasis, (2) food reward and hedonics, (3) reward function in schizophrenia, and (4) metabolic effects of the SGAs. A mesolimbic hyperdopaminergic state may render motivational/incentive reward system insensitive to low salience/palatability food. This, together with poor cognitive control from hypofunctional prefrontal cortex and enhanced hedonic impact of food, owing to exaggerated opioidergic drive (clinically manifested as pain insensitivity), may underlie unhealthy eating habits in patients with schizophrenia. Treatment with SGAs purportedly improves dopamine-mediated reward aspects, but at the cost of increased appetite and worsened or at least not improved opiodergic capacity. These effects can further deteriorate eating patterns. Pathophysiological and therapeutic implications of these insights need further validation via prospective clinical trials and neuroimaging studies.

Effects of olanzapine on aggressiveness in heroin dependent patients

This study compared the anti-aggressiveness effects of the atypical anti-psychotic olanzapine with that of selective serotonin reuptake inhibitors (SSRI) and benzodiazepines (BZD) among patients with heroin dependence submitted to opioid-agonists substitution treatment. Sixty-seven (67) patients who met the DSM-IV criteria for heroin dependence and showed aggressive personality traits, not affected by comorbid schizophrenia or bipolar disorder, accepted to participate in a 12-week prospective, observational trial. Patients were included into two subgroups in relationship with treatment, for the evaluation of the endpoints at week 12: group 1: substitution treatment in combination with OLA (32 patients); group 2: substitution treatment in combination with fluoxetine/paroxetine and clonazepam (35 patients). Efficacy measures were Buss Durkee Hostility Inventory (BDHI), Symptoms Check List-90 (SCL 90) anger--hostility scores, incidence rates of aggressive incidents and attacks. The rates of patients who remained in treatment at week 12 in group 1, treated with OLA, and group 2, treated with SSRI and BDZ, were not significantly different (17 = 53.1% vs 16 = 45.7%). BDHI total, direct aggressiveness, verbal aggressiveness scores, SCL 90 aggressiveness scores and aggressive incidents rates showed a significantly more consistent decrease from baseline in group 1 than in group 2 subjects, in the patients who completed the treatment (p < 0.001; p < 0.01; p < 0.05; p < 0.01; p < 0.001). Among the completers, 69.3% achieved early full substance abuse remission, while 30.7% achieved partial substance abuse remission, with no significant difference between 1 and 2 treatment subgroups. Although obtained by an observational--open clinical study, with multiple limitations, our findings suggest that OLA may be useful as an adjunctive agent in reducing aggressive/hostile behaviour in heroin addicted individuals during maintenance substitution treatment. Otherwise, atypical anti-psychotic OLA seems to be unable to improve the outcome in terms of addictive behavior and relapse risk in the addicted patients not affected by overt psychotic disorders.

Comorbid substance-use in schizophrenia: relation to positive and negative symptoms

As substance use disorders (SUD) are common in schizophrenia patients, we tested the hypothesis that comorbid patients (SUD[+]) have more positive vs. negative symptoms than non-comorbid (SUD[-]) patients. From reports identified by literature-searching we compared Positive and Negative Syndrome Scale (PANSS) ratings in schizophrenia patients with and without SUD using meta-analytic methods. Among 9 comparisons (N=725 subjects), SUD[+] patients were more often men, and abused alcohol>cannabis>cocaine. SUD[+] patients had very significantly higher PANSS-positive, and lower PANSS-negative scores. Comorbid SUD in schizophrenia patients was associated with male sex and higher PANSS positive to lower negative scores. Cause-effect relationships remain to be clarified.

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.

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 effect of olanzapine on craving and alcohol consumption

Previous studies have indicated that olanzapine decreases craving after a priming dose of alcohol, that craving after a priming dose of alcohol is greater among individuals with the seven-repeat allele of the DRD4 variable number of tandem repeats (VNTR) polymorphism, and that the effect of olanzapine (a D2/D4 antagonist) is more pronounced among individuals with this allele. The present study tested the hypothesis that olanzapine may be differentially effective at reducing cue-elicited craving and differentially effective as a treatment for alcohol dependence over the course of a 12-week, randomized, placebo-controlled trial among individuals with and without the seven-repeat allele. Participants who met DSM IV criteria for alcohol dependence were randomly assigned to receive olanzapine (5 mg) or a placebo over the course of the trial. After 2 weeks of treatment, participants completed a cue reactivity assessment. The results suggested that participants who were homozygous or heterozygous for the seven (or longer)-repeat allele of the DRD4 VNTR responded to olanzapine with reductions in cue-elicited craving as well as reductions in alcohol consumption over the course of the 12-week trial, whereas individuals with the shorter alleles did not respond favorably to olanzapine.

Guidelines for the use of clozapine in individuals with developmental disabilities

Clozapine is the most effective antipsychotic medication currently in use, but there has been a paucity of well-controlled research on its efficacy with people with developmental disabilities. We present a set of guidelines to ensure proper utilization of clozapine in individuals with developmental disabilities, because it can offer them therapeutic advantages similar to those observed in people with schizophrenia. We provide recommendations regarding the use of clozapine that are based on three main sources: literature and published professional practice guidelines regarding the use of clozapine in individuals who do not have developmental disabilities, the limited literature on the use of clozapine in individuals who have developmental disabilities, and our own clinical experience. The first part of the guidelines contains an overview of necessary practical knowledge regarding side effects, dose and blood level considerations, and interactions with other medications, diet and tobacco smoking. In the second part, we offer procedures for selecting individuals for clozapine therapy based on proper indications and contraindications for treatment. We also include requirements regarding informed consent, dosage and special laboratory and clinical monitoring.

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.

Cocaine abuse in schizophrenic patients treated with olanzapine versus haloperidol

Comorbid cocaine abuse adversely affects clinical outcomes in schizophrenia. Using a prospective, randomized, parallel group design (N = 24), we tested the hypothesis that patients with schizophrenia treated with olanzapine have reduced cocaine craving and abuse compared with those treated with haloperidol. In addition, we examined whether this differential effect correlated with reductions in extrapyramidal symptoms, positive and negative symptoms, and/or depression. There were no significant differences overall in proportions of positive drug screens between treatment groups; no differences in positive, negative, or depressive symptoms; and few differences between treatment conditions in extrapyramidal symptoms. However, craving for cocaine was rated significantly lower by patients treated with haloperidol compared with patients treated with olanzapine. Important study limitations include a small sample size and high attrition rates. Larger controlled studies are necessary to determine optimal antipsychotic therapy for patients with schizophrenia and comorbid cocaine abuse.

New medication strategies for comorbid substance use and bipolar affective disorders

Comorbidity of substance abuse disorders (SUD) with bipolar disorders (BPD) is a serious treatment problem. Childhood BPD can be further complicated by comorbidity with attention-deficit/hyperactivity disorder (ADHD) and later SUD during adolescence. The aim of this article is to review the literature on pharmacotherapies for these patients. Developing the ideal pharmacotherapy for BPD and SUD can be informed by the role of gamma-aminobutyric acid (GABA) in the neurobiology of SUD. This ideal pharmacotherapy would have several key characteristics. These characteristics include treating the BPD, relieving withdrawal symptoms, and preventing relapse to SUD. The ideal medication should have low abuse liability, require infrequent dosing, be well tolerated, and have few side effects. A medication approaching this ideal is the GABA enhancer valproate. Adding atypical antipsychotic agents might not improve valproate's efficacy, but combining GABA medications with selective serotonin reuptake inhibitors holds promise for SUD with depression. Pemoline might be the best option for minimizing the risk of SUD complicating comorbid ADHD with BPD.

Olanzapine attenuates cue-elicited craving for tobacco

RATIONALE

Recent biological conceptualizations of craving and addiction have implicated mesolimbic dopamine activity as a central feature of the process of addiction. Imaging, and pharmacological studies have supported a role for dopaminergic structures in cue-elicited craving for tobacco.

OBJECTIVE

If mesolimbic dopamine activity is associated with cue-elicited craving for tobacco, a dopamine antagonist should attenuate cue-elicited craving for tobacco. Thus, the aim of the present study was to determine whether an atypical antipsychotic (olanzapine, 5 mg) decreased cue-elicited craving for tobacco.

METHOD

Participants were randomly assigned to 5 days of pretreatment with olanzapine (5 mg; n=31) or were randomly assigned to 5 days of a matching placebo (n=28). Approximately 8 h after the last dose, participants were exposed to a control cue (pencil) followed by exposure to smoking cues. Participants subsequently smoked either nicotine cigarettes or de-nicotinized cigarettes.

RESULTS

Olanzapine attenuated cue-elicited craving for tobacco but did not moderate the subjective effects of smoking.

DISCUSSION

This study represents one of the first investigations of the effect of atypical antipsychotics on cue-elicited craving for tobacco. The results suggest that medications with similar profiles may reduce cue-elicited craving, which in turn, may partially explain recent observations that atypical antipsychotics may reduce substance use.

The neural circuitry of reward and its relevance to psychiatric disorders

Scientific interest in how the brain processes reward has burgeoned during the past 50 years since the discovery that rats will do tasks such as pressing a lever to obtain electrical stimulation of the brain. This interest was additionally encouraged by the observation of an association between reward and dopamine activity in the mesocorticolimbic system. In this article, we will discuss the complex nature of reward processing and recent animal studies and human functional neuroimaging studies to elucidate the current understanding of the neural substrates of reward processing and its components. Lastly, we will review recent theoretical and empirical work investigating the role of brain reward circuitry in several psychiatric disorders, including substance use disorders, schizophrenia, pathologic gambling, major depressive disorder, and attention-deficit/hyperactivity disorder.

Clozapine reduces alcohol drinking in Syrian golden hamsters

Alcohol abuse contributes substantially to the overall morbidity of schizophrenia. While typical antipsychotic medications do not limit alcohol use in patients with schizophrenia, emerging data suggest that the atypical antipsychotic clozapine does. To further elucidate the effects of these antipsychotics on alcohol use, we initiated a study in alcohol-preferring rodents. Syrian golden hamsters were given free-choice, unlimited access to alcohol. Nine days of treatment (s.c. injection) with clozapine (2-4 mg/kg/day), but not haloperidol (0.2-0.4 mg/kg/day), reduced alcohol drinking. Clozapine reduced alcohol drinking by 88% (from 11.3+/-1.7 to 1.4+/-0.2 g/kg/day) while increasing both water and food intake. Alcohol drinking gradually (during 24 days) returned toward baseline in the clozapine-treated animals when vehicle was substituted for clozapine. Further increasing the doses of haloperidol (0.6-1.0 mg/kg/day) had no effect on alcohol drinking; moreover, very low doses of haloperidol (0.025-0.1 mg/kg/day) tested in separate groups of hamsters also had no effect on alcohol drinking. This study demonstrates that clozapine, but not haloperidol, can effectively and reversibly decrease alcohol consumption in alcohol-preferring hamsters. The results are compatible with the observations that clozapine, but not haloperidol, limits alcohol use in patients with schizophrenia. These data further suggest that clozapine may serve as a prototype for developing novel treatments for alcohol abuse.

Reduced dopamine D4 receptor mRNA expression in lymphocytes of long-term abstinent alcohol and heroin addicts

AIM

It has been repeatedly suggested that dopamine receptor expression in peripheral blood lymphocytes reflects, to some extent, brain status. The aim of the present study was to investigate dopamine receptor expression in peripheral blood lymphocytes of long-term abstinent alcohol and heroin addicts against the background of the hypothesis, that a persisting dysfunction of the dopaminergic system contributes a biological cause to the chronic character of addiction.

DESIGN

Dopamine D3 and D4 receptor mRNA expression in peripheral blood lymphocytes was measured by real-time polymerase chain reaction (PCR) in 19 alcohol addicts, abstinent for 6.2 +/- 4.7 months (mean +/- SD), and 20 heroin addicts, abstinent for 6.7 +/- 3.7 months (mean +/- SD), and compared to a control group of 29 age- and sex-matched individuals with no life-time history of substance abuse.

FINDINGS

One-way anova showed significant differences in D4 mRNA expression between the groups (P = 0.005): both groups of addicts showed an approximately 50% reduction in D4 receptor mRNA expression in peripheral blood lymphocytes (PBL) compared to controls. No differences were found for D3 mRNA expression between the groups.

CONCLUSION

The results of the present study indicate a withdrawal-persisting dopaminergic imbalance in abstinent addicts as measured by a suggested peripheral marker.

Pharmacological Treatment of Alcohol Abuse/Dependence With Psychiatric Comorbidity

This article represents the proceedings of a symposium at the 2003 annual meeting RSA in Fort Lauderdale, FL. It was organized and cochaired by Charlene E. Le Fauve and Carrie L. Randall. The presentations were (1) Introduction, by Charlene E. Le Fauve and Raye Z. Litten; (2) Treatment of co-occurring alcohol use and anxiety disorders, by Carrie L. Randall and Sarah W. Book; (3) Pharmacological treatment of alcohol dependent patients with comorbid depression, by Darlene H. Moak; (4) Efficacy of valproate in bipolar alcoholics: a double blind, placebo-controlled study, by Ihsan M. Salloum, Jack R. Cornelius, Dennis C. Daley, Levent Kirisci, Johnathan Himmelhoch, and Michael E. Thase; (5) Alcoholism and schizophrenia: effects of antipsychotics, by Alan I. Green, Robert E. Drake, Suzannah V. Zimmet, Rael D. Strous, Melinda Salomon, and Mark Brenner; and (6) Conclusions, by Charlene E. Le Fauve; discussant, Raye Z. Litten. Alcohol-dependent individuals have exceptionally high rates of co-occurring psychiatric disorders. Although this population is more likely to seek alcoholism treatment than noncomorbid alcoholics, the prognosis for treatment is often poor, particularly among patients with more severe psychiatric illnesses. Development of effective interventions to treat this population is in the early stages of research. Although the interaction between the psychiatric condition and alcoholism is complex, progress has been made. The NIAAA has supported a number of state-of-the-art pharmacological and behavioral trials in a variety of comorbid psychiatric disorders. Some of these trials have been completed and are presented here. The symposium presented some new research findings from clinical studies with the aim of facilitating the development of treatments that improve alcohol and psychiatric outcomes among individuals with alcohol-use disorders and co-occurring psychiatric disorders. The panel focused on social anxiety disorder, depression, bipolar disorder, and schizophrenia.

First episode schizophrenia-related psychosis and substance use disorders: acute response to olanzapine and haloperidol

BACKGROUND

Co-occurring substance use disorders, mostly involving alcohol, cannabis or cocaine, occur commonly in patients with schizophrenia and are associated with increased morbidity and mortality. Available but limited data suggest that substance use disorders (especially cannabis use disorders) may also be common in first-episode patients and appear linked to a poor outcome in these patients. Strategies to curtail substance use form an important dimension of the treatment program for both first-episode and chronic patients. We report on rates of co-occurring substance use disorders in patients within their first episode of schizophrenia-related psychosis from a multicenter, international treatment trial of olanzapine vs. haloperidol.

METHODS

The study involved 262 patients (of 263 who were randomized and who returned for a post-randomization evaluation) within their first episode of psychosis (schizophrenia, schizoaffective disorder or schizophreniform disorder) recruited from 14 academic medical centers in North America and Western Europe. Patients with a history of substance dependence within 1 month prior to entry were excluded.

RESULTS

Of this sample, 97 (37%) had a lifetime diagnosis of substance use disorder (SUD); of these 74 (28% of the total) had a lifetime cannabis use disorder (CUD) and 54 (21%) had a lifetime diagnosis of alcohol use disorder (AUD). Patients with SUD were more likely to be men. Those with CUD had a lower age of onset than those without. Patients with SUD had more positive symptoms and fewer negative symptoms than those without SUD, and they had a longer duration of untreated psychosis. The 12-week response data indicated that 27% of patients with SUD were responders compared to 35% of those without SUD. Patients with AUD were less likely to respond to olanzapine than those without AUD.

DISCUSSION

These data suggest that first-episode patients are quite likely to have comorbid substance use disorders, and that the presence of these disorders may negatively influence response to antipsychotic medications, both typical and atypical antipsychotics, over the first 12 weeks of treatment.

Evolving U.S. service model for patients with severe mental illness and co-occurring substance use disorder

Co-occurring severe mental illness and substance use disorder has been recognized as a common problem in the U.S. since the early 1980s (1-3). For these individuals with co-occurring disorders, research demonstrates the effectiveness of various forms of combining, blending, or integrating mental health and substance abuse treatments (4). The evolving U.S. service model for integrated dual disorders treatment emphasizes several key elements: implementation, leadership, training, engagement, assessment, counseling for all patients, ancillary treatments for those with multiple needs, secondary treatments for patients who are nonresponders, and quality assurance regarding process and outcomes.

Relationship of clinical symptoms and substance use in schizophrenia patients on conventional versus atypical antipsychotics

A large body of research documents the high prevalence and devastating consequences of substance abuse among individuals diagnosed with schizophrenia. One prominent theory of the high rate of comorbidity between these disorders is that substance abuse in schizophrenia is an attempt to self-medicate psychiatric symptoms including negative symptoms and depression as well as side effects including extrapyramidal reactions (EPR). Consistent with this notion, novel antipsychotic medications, which have been shown to reduce negative and depressive symptoms while exhibiting a lower propensity to cause EPR, have been associated with reduced substance abuse in patients with schizophrenia. To further explore the self-medication hypothesis as it relates to the mechanism by which atypical antipsychotics reduce substance abuse, we compared schizophrenia patients with a history of substance abuse medicated with either conventional (n = 35) or atypical (n = 35) antipsychotics. Patients with schizophrenia who did not have a history of substance abuse who were on conventional (n = 23) vs. atypical antipsychotics (n = 29) were also examined. Assessments included the Positive and Negative Symptom Scale, Hamilton Rating Scale for Depression, Simpson-Angus, and Abnormal Involuntary Movement Scale. Compared with conventional medications, atypical antipsychotic drugs were associated with reduced levels of substance use (primarily alcohol). Interestingly, however, in substance-abusing patients there were no significant differences between patients on conventional vs. atypical agents with respect to positive or negative symptoms, depression, or EPR. These data suggest that theories related to self-medication of symptoms and side effects do not appear to account for the difference in rates of substance use found in schizophrenia patients on atypical vs. conventional antipsychotic medications.

Pharmacotherapy for schizophrenia and co-occurring substance use disorders

Research on the optimal pharmacotherapy for people with schizophrenia and co-occurring substance use disorders remains in its infancy. This report reviews existing data and provides an update on recent research. The confluence of findings is consistent with a model of a reward dysfunction inherent in the neuropathology of schizophrenia, leading to a heightened vulnerability of people with schizophrenia to substance use disorders. Studies indicate that patients with dual disorders have difficulty tolerating conventional antipsychotics, have higher rates of medication nonadherence, and have greater impulsivity and sensation seeking. Limited evidence suggests that clozapine treatment may be associated with reduced substance abuse, with weaker evidence suggesting that other novel antipsychotics may have similar, but potentially less potent, effects. Controlled trials to test the effects of these medications are underway. A number of recent studies indicate that bupropion can facilitate reduced tobacco smoking among patients with schizophrenia. The preferential use of novel antipsychotics, a lower threshold for prescription of clozapine, the use of bupropion for smoking cessation, careful monitoring of compliance, and possible use of other medications for substance use disorders when indicated are recommended in pharmacologic management for people with co-occurring substance use disorders and schizophrenia.