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.

Proceedings and data from The Schizophrenia Summit: a critical appraisal to improve the management of Schizophrenia

In mid-February 2008, a panel of 10 nationally recognized schizophrenia research experts was assembled in a Schizophrenia Summit to focus on controversies that exist in treating patients with schizophrenia. The current literature related to the diagnosis and etiopathology of schizophrenia was evaluated regarding the identification of a prodromal phase, brain changes, cognitive impairments, genetic factors, and use of neuroimaging in patients with schizophrenia. Further, consideration was given to evidence supporting the neuroprotective benefits of atypical antipsychotic medications, the benefits of treating patients during the prodromal period, the use of combination antipsychotic medications, the need to improve cognitive function, and the management of substance abuse. Summit faculty member opinion is compared with field survey results, and recommendations are made for future research.

Hyperactivity and hyperconnectivity of the default network in schizophrenia and in first-degree relatives of persons with schizophrenia

We examined the status of the neural network mediating the default mode of brain function, which typically exhibits greater activation during rest than during task, in patients in the early phase of schizophrenia and in young first-degree relatives of persons with schizophrenia. During functional MRI, patients, relatives, and controls alternated between rest and performance of working memory (WM) tasks. As expected, controls exhibited task-related suppression of activation in the default network, including medial prefrontal cortex (MPFC) and posterior cingulate cortex/precuneus. Patients and relatives exhibited significantly reduced task-related suppression in MPFC, and these reductions remained after controlling for performance. Increased task-related MPFC suppression correlated with better WM performance in patients and relatives and with less psychopathology in all 3 groups. For WM task performance, patients and relatives had greater activation in right dorsolateral prefrontal cortex (DLPFC) than controls. During rest and task, patients and relatives exhibited abnormally high functional connectivity within the default network. The magnitudes of default network connectivity during rest and task correlated with psychopathology in the patients. Further, during both rest and task, patients exhibited reduced anticorrelations between MPFC and DLPFC, a region that was hyperactivated by patients and relatives during WM performance. Among patients, the magnitude of MPFC task suppression negatively correlated with default connectivity, suggesting an association between the hyperactivation and hyperconnectivity in schizophrenia. Hyperactivation (reduced task-related suppression) of default regions and hyperconnectivity of the default network may contribute to disturbances of thought in schizophrenia and risk for the illness.

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.

Clozapine-induced myocarditis: role of catecholamines in a murine model

Clozapine, an atypical antipsychotic, is very effective in the treatment of resistant schizophrenia. However, cardiotoxicity of clozapine, particularly in young patients, has raised concerns about its safety. Increased catecholamines have been postulated to trigger an inflammatory response resulting in myocarditis, dilated cardiomyopathy, and death, although this has not yet been thoroughly studied. Here, we used the mouse to study whether clozapine administration could cause adverse myocarditis associated with an increase in catecholamines. Male Balb/C mice, age ~6 weeks, were administered 5, 10 or 25 mg/kg clozapine daily for 7 and 14 days; one group was administered 25 mg/kg clozapine plus 2 mg/kg propranolol for 14 days. Saline-treated mice served as controls. Heart sections were stained with hematoxylin and eosin for histopathological examination. Plasma catecholamines were measured with HPLC. Myocardial TNF-alpha concentrations were determined by ELISA. Histopathology of clozapine-treated mice showed a significant dose-related increase in myocardial inflammation that correlated with plasma catecholamine levels and release of TNF-alpha. Propranolol significantly attenuated these effects. A hypercatecholaminergic state induced by clozapine could explain the occurrence of myocarditis in some patients. Our data suggest that a beta-adrenergic blocking agent may be effective in reducing the incidence and severity of clozapine-induced myocarditis.

Developing and testing adaptive treatment strategies using substance-induced psychosis as an example

Decisions concerning treatment changes pervade the management of chronic psychiatric disorders that resist definitive cure, yet empirical evidence for the comparative clinical effectiveness of treatment strategies remains underdeveloped. In this paper we exploit the example of psychosis following substance use to illustrate some new developments in clinical trials design that can provide the most solid evidence base for defining successful strategies. The intent is to explore the strengths and limitations of the methodological approach through a meaningful clinical example, with an emphasis on concepts and issues. Both methodology and clinical science are overviewed.

Longer time to antipsychotic treatment discontinuation for any cause is associated with better functional outcomes for patients with schizophrenia, schizophreniform disorder, or schizoaffective disorder

OBJECTIVE

Time to all-cause treatment discontinuation is considered a composite proxy measure of treatment efficacy, safety, and tolerability. Longer time to discontinuation of antipsychotic medication for any cause has been shown to be associated with greater symptom improvements in the treatment of schizophrenia. This study examines whether longer time to all-cause medication discontinuation is also linked to better functional outcomes.

METHOD

Using pooled data from 4 randomized, double-blind antipsychotic trials of 24- to 28-weeks' duration, this study examined the association between time to all-cause treatment discontinuation and functional outcomes, as assessed by a disease-specific, clinician-rated measure (Quality of Life Scale [QLS]) and a generic, patient-reported measure (Medical Outcomes Study Short Form 36 [SF-36]). Patients in these trials had a DSM-IV diagnosis of schizophrenia, schizophreniform disorder, or schizoaffective disorder. This post hoc analysis used Pearson partial correlations to assess relationships between time to treatment discontinuation and changes in functional scores, adjusting for baseline scores. Repeated measures analyses were also conducted to compare post-baseline functional outcome change over time between completers and noncompleters.

RESULTS

Longer time to all-cause treatment discontinuation was found to be significantly associated with greater improvements in all assessed functional domains (p < .05). Patients who completed their respective trials (46.8%, 761/1627) experienced significantly greater improvement in functional outcome measures (in 4 QLS domains and SF-36 mental health component summary score; all, p < .001) compared to patients who discontinued for any cause. In addition, greater symptom improvement was significantly associated with greater functional improvements in assessed domains.

CONCLUSIONS

Findings from this post hoc analysis illustrate the importance of longer treatment duration with antipsychotics for improving functional outcomes in the treatment of patients with schizophrenia.

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.

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.

Clozapine use and relapses of substance use disorder among patients with co-occurring schizophrenia and substance use disorders

BACKGROUND

Previous correlational research with schizophrenic patients has suggested that the second-generation antipsychotic medication clozapine helps to induce remissions of substance use disorder in patients with co-occurring psychosis and substance abuse. This research, however, could be biased by selection factors. Studying patients who are currently in substance abuse remission could control for level of motivation to stop using substances and other methodological confounds.

METHODS

To test whether clozapine was associated with prevention of substance abuse relapses, we examined patients with schizophrenia or schizoaffective disorder who were in their first 6-month remission of substance use disorder during a prospective 10-year follow-up study. All patients received yearly multimodal assessments of substance use. Antipsychotic medications were prescribed by community doctors as part of usual clinical care.

RESULTS

Patients using clozapine at the first 6-month period of substance abuse remission (n = 25) were much less likely to relapse over the next year compared with those on other antipsychotic medications (n = 70): 8.0% vs 40.0%, chi(2) = 8.73 (df = 1), P = .003. Although medication assignment was not randomized, several potential confounders were similar between the groups.

CONCLUSION

Clozapine should be considered for the treatment of patients with schizophrenia and co-occurring substance use disorder to prevent relapses to substance abuse.

Enhancing validity in co-occurring disorders treatment research

Despite the high prevalence of co-occurring mental health and substance-use disorders, there has been a relative lack of treatment research with this population, and the existing research often has limited validity. This article explores some of the barriers to the conduct of research on promising interventions for substance-abuse treatment for people with co-occurring disorders, using the concepts of external and ecological validity to make recommendations for future investigation. The central recommendation is to move rapidly from efficacy studies to more credible and valid effectiveness studies, in order to facilitate the adoption of evidence-based interventions in routine practice settings.

Treatment of schizophrenia and comorbid substance abuse: pharmacologic approaches

Co-occurring substance use disorder is common among patients with schizophrenia, and its presence greatly worsens the course of schizophrenia. A number of theories have been introduced to explain the increased rate of substance use disorder in these patients. These theories include the notion that substance use could trigger psychotic symptoms in vulnerable individuals and the idea that the substances are used to self-medicate symptoms of schizophrenia. Our group and others have advanced a neurobiological hypothesis to explain this comorbidity-that a mesocorticolimbic brain reward circuit underlies the substance use disorder in patients with schizophrenia. Treatment of substance use disorder in these patients is best done with integrated treatment programs that combine psychosocial interventions with pharmacotherapy. Recent data suggest that the atypical antipsychotic clozapine and perhaps other atypical agents may lessen substance use in patients with schizophrenia. My colleagues and I have proposed that clozapine's effect in these patients may be related to its ability to decrease the brain reward circuit dysfunction. Research is continuing on the use of atypical antipsychotics in patients with schizophrenia and comorbid substance abuse. The adjunctive use of naltrexone or other agents also may be helpful. Further research on the optimal pharmacologic approach to patients with dual diagnosis is needed.

Olanzapine and haloperidol in first episode psychosis: two-year data

Few studies have assessed the comparative efficacy and safety of atypical and typical antipsychotic medications in patients within their first episode of psychosis. This study examined the effectiveness of the atypical antipsychotic olanzapine and the typical antipsychotic haloperidol in patients experiencing their first episode of a schizophrenia-related psychotic disorder over a 2-year treatment period. Two hundred and sixty-three patients were randomized to olanzapine or haloperidol in a doubleblind, multisite, international 2-year study. Clinical symptoms and side effects were assessed at baseline and longitudinally following randomization for the duration of the study. Olanzapine and haloperidol treatment were both associated with substantial and comparable reductions in symptom severity (the primary outcome measure) over the course of the study. However, the treatment groups differed on two secondary efficacy measures. Patients were less likely to discontinue treatment with olanzapine than with haloperidol: mean time (in days) in the study was significantly greater for those treated with olanzapine compared to haloperidol (322.09 vs. 230.38, p<0.0085). Moreover, remission rates were greater in patients treated with olanzapine as compared to those treated with haloperidol (57.25% vs. 43.94%, p<0.036). While extrapyramidal side effects were greater in those treated with haloperidol, weight gain, cholesterol level and liver function values were greater in patients treated with olanzapine. The data from this study suggest some clinical benefits for olanzapine as compared to haloperidol in first episode patients, which must be weighed against those adverse effects that are more likely with olanzapine.

Comorbid schizophrenia and substance abuse

At some point during their lives, many patients with schizophrenia abuse substances. The co-occurrence of substance use leads to poorer long- and short-term outcomes in schizophrenia and complicates the treatment of both conditions. The primary substances of abuse among schizophrenia patients are alcohol, cannabis, cocaine, and nicotine. This presentation describes the prevalence, outcomes, and basis for this comorbidity. A brief discussion about the neurobiology of schizophrenia explains how schizophrenia may create a biologic predisposition to substance abuse by altering the brain reward system. The efficacy of possible treatments for comorbid schizophrenia and substance abuse are weighed, including typical and atypical antipsychotics and psychosocial interventions, and a list of possible adjunctive agents is provided.

Predictors of antipsychotic medication adherence in patients recovering from a first psychotic episode

BACKGROUND

Many patients recovering from a first psychotic episode will discontinue medication against medical advice, even before a 1-year treatment course is completed. Factors associated with treatment adherence in patients with chronic schizophrenia include beliefs about severity of illness and need for treatment, treatment with typical versus atypical antipsychotic and medication side effects.

METHOD

In this 2-year prospective study of 254 patients recovering from a first episode of schizophrenia, schizophreniform, or schizoaffective disorder we examined the relationship between antipsychotic medication non-adherence and patient beliefs about: need for treatment, antipsychotic medication benefits, and negative aspects of antipsychotic medication treatment. We also examined the relationship between medication non-adherence and treatment with either haloperidol or olanzapine, and objective measures of symptom response and side effects.

RESULTS

The likelihood of becoming medication non-adherent for 1 week or longer was greater in subjects whose belief in need for treatment was less (HR=1.75, 95% CI 1.16, 2.65, p=0.0077) or who believed medications were of low benefit (HR=2.88, 95 CI 1.79-4.65, p<0.0001). Subjects randomized to haloperidol were more likely to become medication non-adherent for >or=1 week than subjects randomized to olanzapine (HR-1.51, 95% CI 1.01, 2.27, p=0.045).

CONCLUSION

Beliefs about need for treatment and the benefits of antipsychotic medication may be intervention targets to improve likelihood of long-term medication adherence in patients recovering from a first episode of schizophrenia, schizoaffective, or schizophreniform disorder.

Course and predictors of weight gain in people with first-episode psychosis treated with olanzapine or haloperidol

BACKGROUND

Substantial weight gain is common with many atypical antipsychotics.

AIMS

To evaluate the extent, time course and predictors of weight gain and its effect on study retention among people with first-episode psychosis treated with olanzapine or haloperidol.

METHOD

Survival analysis assessed time to potentially clinically significant weight gain (> or =7%) and the effect of weight gain on study retention. Weight gain during the 2-year study was summarised using last-observation-carried-forward (LOCF), observed cases and study completion approaches.

RESULTS

After 2 years of treatment, LOCF mean weight gain was 10.2 kg (s.d.=10.1) for olanzapine (n=131) and 4.0 kg (s.d.=7.3) for haloperidol (n=132); observed cases mean weight gain was 15.4 kg (s.d.=10.0) for olanzapine and 7.5 kg (s.d.=9.2) for haloperidol. Change in body mass index was significantly predicted only by treatment group (P < 0.0001).

CONCLUSIONS

Olanzapine was associated with significantly greater weight gain than haloperidol, with both leading to greater weight gain than previously described.

Schizophrenia and comorbid substance use disorder: effects of antipsychotics

The rate of comorbid substance use disorder in patients with schizophrenia is 3 times higher than that in the general population. Men with schizophrenia appear to be particularly vulnerable to substance use disorders. Substances commonly abused in patients with schizophrenia include alcohol, cannabis, and cocaine. Although the basis of comorbidity is unclear, a number of theories have been proposed, including the possibility of a deficiency in the dopamine-mediated mesocorticolimbic brain reward circuit. Data suggest that substance abuse may complicate and worsen the course of schizophrenia. Early intervention with appropriate pharmacotherapy may prove beneficial and potentially improve the long-term course of the disorder. Conventional antipsychotics have not been overly useful in this patient population, but some atypical antipsychotics have been shown to reduce the use of alcohol, cannabis, cocaine, and tobacco in patients with schizophrenia. Further research is required, but early evidence suggests that at least some atypical antipsychotics may prove to be therapeutically effective in the treatment of patients with schizophrenia and comorbid substance use disorder.

Quality of life during treatment with haloperidol or olanzapine in the year following a first psychotic episode

OBJECTIVES

Schizophrenia causes significant impairments of quality of life. As treatment approaches have advanced, more attention has been given to re-integrating patients into their psychosocial environments, rather than simply monitoring psychotic symptoms. The development of the second-generation antipsychotics raised hope that these medications would provide better quality of life improvement than conventional antipsychotics. This improvement is particularly relevant early in the course of schizophrenia.

METHODS

To address these considerations, improvements in measures of general health and social function (determined using the SF-36) were assessed in 195 patients with first-episode schizophrenia for up to one year following randomization to either olanzapine or haloperidol in a double blind clinical trial. We hypothesized that olanzapine would demonstrate better improvement on these measures than haloperidol. In order to test this hypothesis, we used a repeated measure model with SF-36 scores as the outcome, and treatment group, time, time2, time-by-treatment group interaction, and time2-by-treatment group interaction as fixed effects.

RESULTS

Both treatments demonstrated similar changes on the SF-36. Independent of treatment, patients demonstrated significant improvements in most of the SF-36 subscales, which approached normative scores by the end of one year of treatment. Forty-six of 100 olanzapine-treated patients and 37 of 95 haloperidol-treated patients completed the one year of this study (p<.4).

CONCLUSIONS

These results suggest an important initial treatment goal for patients with new onset schizophrenic disorders, namely that they can expect to recover significant quality of life and social function at least initially in treatment.

Improving the care of individuals with schizophrenia and substance use disorders: consensus recommendations

National attention continues to focus on the need to improve care for individuals with co-occurring mental illnesses and substance use disorders, as emphasized in the 2003 President's New Freedom Commission Report on Mental Health and recent publications from the Substance Abuse and Mental Health Services Administration (SAMHSA). These reports document the need for best practice recommendations that can be translated into routine clinical care. Although efforts are underway to synthesize literature in this area, few focused recommendations are available that include expert opinion and evidence-based findings on the management of specific co-occurring disorders, such as schizophrenia and addiction. In response to the need for user-friendly recommendations on the treatment of schizophrenia and addiction, a consensus conference of experts from academic institutions and state mental health systems was organized to 1) frame the problem from clinical and systems-level perspectives; 2) identify effective and problematic psychosocial, pharmacological, and systems practices; and 3) develop a summary publication with recommendations for improving current practice. The results of the consensus meeting served as the foundation for this publication, which presents a broad set of recommendations for clinicians who treat individuals with schizophrenia. "Integrated treatment" is the new standard for evidence-based treatment for this population and recommendations are given to help clinicians implement such integrated treatment. Specific recommendations are provided concerning screening for substance use disorders in patients with schizophrenia, assessing motivation for change, managing medical conditions that commonly occur in patients with dual diagnoses (e.g., cardiovascular disease, liver complications, lung cancer, HIV, and hepatitis B or C infections) and selecting the most appropriate medications for such patients to maximize safety and minimize drug interactions, use of evidence-based psychosocial interventions for patients with dual diagnoses (e.g., Dual Recovery Therapy, modified cognitive-behavioral therapy, modified motivational enhancement therapy, and the Substance Abuse Management Module), and key pharmacotherapy principles for treating schizophrenia, substance use disorders, and comorbid anxiety, depression, and sleep problems in this population. Finally the article reviews programmatic and systemic changes needed to overcome treatment barriers and promote the best outcomes for this patient population. An algorithm summarizing the consensus recommendations is provided in an appendix.

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.