Pharmacological treatment of schizophrenia and co-occurring substance use disorders

Comparative Effectiveness of Adjunctive Psychotropic Medications in Patients With Schizophrenia

IMPORTANCE

People with schizophrenia are commonly treated with psychotropic medications in addition to antipsychotics, but there is little evidence about the comparative effectiveness of these adjunctive treatment strategies.

OBJECTIVE

To study the comparative real-world effectiveness of adjunctive psychotropic treatments for patients with schizophrenia.

DESIGN, SETTING, AND PARTICIPANTS

This comparative effectiveness study used US national Medicaid data from January 1, 2001, to December 31, 2010, to examine the outcomes of initiating treatment with an antidepressant, a benzodiazepine, a mood stabilizer, or another antipsychotic among adult outpatients (aged 18-64 years) diagnosed with schizophrenia who were stably treated with a single antipsychotic. Data analysis was performed from January 1, 2017, to June 30, 2018. Multinomial logistic regression models were used to estimate propensity scores to balance covariates across the 4 medication groups. Weighted Cox proportional hazards regression models were used to compare treatment outcomes during 365 days on an intention-to-treat basis.

MAIN OUTCOMES AND MEASURES

Risk of hospitalization for a mental disorder (primary), emergency department (ED) visits for a mental disorder, and all-cause mortality.

RESULTS

The study cohort included 81 921 adult outpatients diagnosed with schizophrenia (mean [SD] age, 40.7 [12.4] years; 37 515 women [45.8%]) who were stably treated with a single antipsychotic and then initiated use of an antidepressant (n = 31 117), a benzodiazepine (n = 11 941), a mood stabilizer (n = 12 849), or another antipsychotic (n = 26 014) (reference treatment). Compared with initiating use of another antipsychotic, initiating use of an antidepressant was associated with a lower risk (hazard ratio [HR], 0.84; 95% CI, 0.80-0.88) of psychiatric hospitalization, whereas initiating use of a benzodiazepine was associated with a higher risk (HR, 1.08; 95% CI, 1.02-1.15); the risk associated with initiating use of a mood stabilizer (HR, 0.98; 95% CI, 0.94-1.03) was not significantly different from initiating use of another antipsychotic. A similar pattern of associations was observed in psychiatric ED visits for initiating use of an antidepressant (HR, 0.92; 95% CI, 0.88-0.96), a benzodiazepine (HR, 1.12; 95% CI, 1.07-1.19), and a mood stabilizer (HR, 0.99; 95% CI, 0.94-1.04). Initiating use of a mood stabilizer was associated with an increased risk of mortality (HR, 1.31; 95% CI, 1.04-1.66).

CONCLUSIONS AND RELEVANCE

In the treatment of schizophrenia, initiating adjunctive treatment with an antidepressant was associated with reduced risk of psychiatric hospitalization and ED visits compared with initiating use of alternative psychotropic medications. Associations of benzodiazepines and mood stabilizers with poorer outcomes warrant clinical caution and further investigation.

Efficacy, acceptability and tolerability of antipsychotics in patients with schizophrenia and comorbid substance use. A systematic review and meta-analysis

Patients with schizophrenia and substance related comorbidity or substance induced psychotic disorder are difficult to treat. Although the prevalence of a comorbid substance use is approximately 40% in schizophrenia, such patients are usually excluded from clinical trials. We therefore performed a random-effects meta-analysis of all randomized controlled antipsychotic drug trials in this patient subgroup. We searched multiple databases up to May, 2018. The primary outcome was the reduction of substance user; secondary outcomes were craving, mean reduction of substance use, overall change in schizophrenia symptoms, positive and negative symptoms, response, dropouts, quality of life, social functioning, weight gain, sedation, prolactin, extrapyramidal side effects and use of antiparkinsonian medication. We identified 27 references from 19 RCTs published from 1999 to March 2017 including 1742 participants. The most frequent types of substance abuse were cannabis (8 studies) and cocaine (6 studies) use/dependence. Clozapine was superior to other antipsychotics for reduction of substance use and risperidone to olanzapine for craving. Olanzapine, clozapine and risperidone showed superiority for symptom reduction compared to some other drugs. When reported, results of side-effects followed known patterns. The evidence-base is considerable (19 RCTs), however, firm conclusions cannot be drawn due to small sample sizes of individual studies and insufficient reporting.

Revisiting the 'self-medication' hypothesis in light of the new data linking low striatal dopamine to comorbid addictive behavior

Persons with schizophrenia are at a high risk, almost 4.6 times more likely, of having drug abuse problems than persons without psychiatric illness. Among the influential proposals to explain such a high comorbidity rate, the 'self-medication hypothesis' proposed that persons with schizophrenia take to drugs in an effort to cope with the illness and medication side effects. In support of the self-medication hypothesis, data from our earlier clinical study confirmed the strong association between neuroleptic dysphoria and negative subjective responses and comorbid drug abuse. Though dopamine has been consistently suspected as one of the major culprits for the development of neuroleptic dysphoria, it is only recently our neuroimaging studies correlated the emergence of neuroleptic dysphoria to the low level of striatal dopamine functioning. Similarly, more evidence has recently emerged linking low striatal dopamine with the development of vulnerability for drug addictive states in schizophrenia. The convergence of evidence from both the dysphoria and comorbidity research, implicating the role of low striatal dopamine in both conditions, has led us to propose that the person with schizophrenia who develops dysphoria and comorbid addictive disorder is likely to be one and the same.

Predictors of response to second generation antipsychotics in drug naïve patients with schizophrenia: a 1 year follow-up study in Shanghai

Response and remission are of great importance to patients with first-episode schizophrenia. Although previous researches have revealed characteristics related to medication response, there is rarely data over remission-related factors. We presume that factors correlated to response may also influence remission in 1 year treatment for first-episode schizophrenia. 398 drug-naïve patients met the criteria of schizophrenia using ICD-10 criteria were recruited from Shanghai Mental Health Center and treated with one of three second generation antipsychotics (risperidone, olanzapine or quetiapine). Patients were followed up for 1 year and assessed at 2 weeks, and then 2, 3, 6, 8 and 12 months. Severity of symptom was evaluated using the Chinese version of the Positive and Negative Syndrome Scale (PANSS). Response was defined as a reduction of 50% or more PANSS scores. The 8-item criteria of remission (proposed by the Remission of Schizophrenia Working Group) were used. Logistic regression analysis revealed that shorter duration of untreated psychosis (DUP), longer treatment time, higher baseline PANSS positive score and higher PANSS general pathological scores predicted response, and acute prodromal phase was the independent factor for remission. These results indicate baseline characters that related to response and those related to remission may be different for patients with schizophrenia.

Opiate dependence in schizophrenia: case presentation and literature review

In the past decade opioid pain reliever misuse among the U.S. population has increased to epidemic proportions. While the U.S. has only 4% of the world's population, Americans consume 86% of the world's opioids. In 2011, approximately 13 million people (5% of the U.S. population) reported nonmedical use of prescription opioids, which are now the second most commonly abused class of drug behind cannabis. There has been little in the way of formal study examining the association between mental illness and prescription opiate abuse, but preliminary evidence suggests a strong association. Neurobiological processes involved in psychosis and opiate abuse may partially explain this association. Despite compelling evidence of the growth in opiate misuse and the potential relationship with mental illness, patients with mental disorders and/or substance abuse are routinely excluded from randomized trials, making it impossible to better understand these phenomena. Treatment guidelines, especially regarding opioid agonists such as methadone and buprenorphine for people with mental illness, are woefully inadequate. We present the case of a young man with schizoaffective disorder who sustained an injury and developed chronic back pain. Opioids were prescribed and he quickly progressed to abusing increasing doses of opioids, which eventually led to daily heroin use. The young man struggled with repeated relapses, serious use-related consequences and suicide attempts. This case highlights the role of chronic pain and opioid prescribing, the segue from prescribed use to abuse and dependence, and the transition to heroin use. It demonstrates the difficulty patients may have in obtaining adequate treatment for co-occurring mental illness and substance abuse and how outcomes are improved when treatment is integrated to address both disorders. Comprehensive treatment must involve a combination of case management and medical management, including possible opioid replacement therapy.

Test-retest reliability of self-report measures in a dually diagnosed sample

Many individuals diagnosed with a substance use disorder are also diagnosed with another psychiatric disorder. Little is known regarding which treatments are efficacious for these dually diagnosed individuals (DDI). Characterizing the psychometric properties of assessments used with DDI samples is essential to efficacy studies with DDI. This study examined the internal consistency and test-retest reliability of self-report instruments among DDI. Most subscales demonstrated high test-retest reliability; one subscale demonstrated poor reliability. Internal consistency was similar to that of non-DDI samples. This exploratory study suggests that, while some instruments should be interpreted cautiously, DDI samples can be accurately assessed with self-report measures.

Antipsychotic treatment of adolescent dual diagnosis patients

BACKGROUND

A diagnosis of schizophrenia requires development of a pharmacotherapy regimen that balances many factors in the therapeutic decision-making process. Patient age and the presence or absence of comorbid chemical dependency represent two factors. Comorbid chemical dependency can have a profound impact on the successful treatment of schizophrenia, making patients with dual diagnoses of schizophrenia and chemical dependence a uniquely challenging population. There is little information regarding treatment of schizophrenia and chemical dependence in the pediatric population. Existing data from pediatric and adult populations may facilitate a well-guided and knowledgeable approach to treating pediatric dual diagnosis patients.

METHODS

A review of the literature for medication trials evaluating antipsychotic medication used to treat schizophrenia in childhood and adolescence as well as antipsychotic use in the treatment of the dual diagnoses of schizophrenia and chemical dependence was done. Databases for Ovid MEDLINE, PubMed, and PsycInfo were searched using the terms "addiction," "adolescence," "childhood," "dual diagnosis," "schizophrenia," and "substance abuse." Results were limited to English-language articles.

RESULTS

Seven articles were identified related to psychotic disorders and substance abuse in pediatric populations. Psychosis measurement instruments included the Brief Psychiatric Rating Scale, Positive and Negative Syndrome Scale, and Clinical Global Impression. Mean improvements were insignificant in most cases. Medication trials included clozapine, olanzapine, risperidone, and molindone. Trial safety concerns included metabolic effects, increased prolactin levels, and akathisia. One study with random assignment to olanzapine was discontinued early because of substantial weight gain without evidence of superior efficacy. Clozapine treatment was associated with more adverse drug events.

CONCLUSION

There is a great need for more research and use of available data to develop safe and effective treatment guidelines for childhood and adolescent dual diagnosis patients. When appropriate decisions are made regarding treatment of patients with comorbid schizophrenia and chemical dependence, both conditions may benefit with increased remission.

Is it time to consider comorbid substance abuse as a new indication for antipsychotic drug development?

Comorbid drug abuse in schizophrenia has been consistently reported as high, with estimates ranging between 10-70%. Comorbid addictive states in schizophrenia are possibly multifactorial, yet recent research assigns a significant neurobiological role in its genesis. Abnormalities in hippocampal/cortical function in schizophrenia which mediate reward and reinforcement behavior are identified as central to the development and maintenance of comorbid addictive states. Preliminary data suggest that the vulnerability of patients with schizophrenia to substance use disorders may be a primary disease symptom. The management of comorbid substance abuse in schizophrenia relies on the use of antipsychotic medications. Recent data raise the concern about whether first-generation antipsychotics in long-term use can conversely lead to enhancement of the abused substance's reinforcing properties. Some recent reports have assigned a favorable outcome to clozapine and second-generation antipsychotics, pointing to a possible differential role for various antipsychotics. In view of the high prevalence of comorbid drug abuse in schizophrenia, its impact on outcome of treatment and the recent emerging neurobiological information, it is my contention that comorbid drug abuse constitutes a dimension by itself and deserves to receive an indication in the development of new antipsychotics similar to negative symptoms or cognitive deficits.

Differences in craving for cannabis between schizophrenia patients using risperidone, olanzapine or clozapine

Substance abuse and psychotic disorders have a high rate of comorbidity. Both disorders are associated with changes in the dopaminergic transmission in the mesocorticolimbic pathways of the brain. Since antipsychotic medications interact with the dopamine receptors in these pathways, these medications could affect craving for substances. In the current study, the effect of clozapine (n = 27, mean dosage 350 mg), risperidone (n = 54, mean dosage 3.46 mg) and olanzapine (n = 60, mean dosage 13.78 mg) on subjective craving for cannabis was compared in 123 patients with cannabis dependence and psychotic disorder. Patients treated with risperidone reported significantly more craving compared with patients treated with clozapine (Z = -3.19, p = .001) or olanzapine (Z = -2.24, p = .025). No significant differences in craving between clozapine and olanzapine were found. These results are in concordance with findings in the literature on this subject and could be explained by differences in three dopamine mediated mechanisms of these compounds: 1) occupancy rate of dopamine D(2) receptors, 2) dissociation rate of dopamine D(2) receptors, 3) D(1)/D(2) occupancy ratio. Risperidone and clozapine show a maximal difference in D(2) receptor occupancy rate, dissociation rate and D(1)/D(2) ratio. Olanzapine is intermediate between risperidone and clozapine in these characteristics.

Treatment of substance abusing patients with comorbid psychiatric disorders

OBJECTIVE

To update clinicians on the latest in evidence-based treatments for substance use disorders (SUD) and non-substance use disorders among adults and suggest how these treatments can be combined into an evidence-based process that enhances treatment effectiveness in comorbid patients.

METHOD

Articles were extracted from Pubmed using the search terms "dual diagnosis," "comorbidity" and "co-occurring" and were reviewed for evidence of effectiveness for pharmacologic and psychotherapeutic treatments of comorbidity.

RESULTS

Twenty-four research reviews and 43 research trials were reviewed. The preponderance of the evidence suggests that antidepressants prescribed to improve substance-related symptoms among patients with mood and anxiety disorders are either not highly effective or involve risk due to high side-effect profiles or toxicity. Second generation antipsychotics are more effective for treatment of schizophrenia and comorbid substance abuse and current evidence suggests clozapine, olanzapine and risperidone are among the best. Clozapine appears to be the most effective of the antipsychotics for reducing alcohol, cocaine and cannabis abuse among patients with schizophrenia. Motivational interviewing has robust support as a highly effective psychotherapy for establishing a therapeutic alliance. This finding is critical since retention in treatment is essential for maintaining effectiveness. Highly structured therapy programs that integrate intensive outpatient treatments, case management services and behavioral therapies such as Contingency Management (CM) are most effective for treatment of severe comorbid conditions.

CONCLUSIONS

Creative combinations of psychotherapies, behavioral and pharmacological interventions offer the most effective treatment for comorbidity. Intensity of treatment must be increased for severe comorbid conditions such as the schizophrenia/cannabis dependence comorbidity due to the limitations of pharmacological treatments.