The effects of galantamine on psychopathology in chronic stable schizophrenia

Intranasal Peptide Therapeutics: A Promising Avenue for Overcoming the Challenges of Traditional CNS Drug Development

The central nervous system (CNS) has, among all organ systems in the human body, the highest failure rate of traditional small-molecule drug development, ranging from 80-100% depending on the area of disease research. This has led to widespread abandonment by the pharmaceutical industry of research and development for CNS disorders, despite increased diagnoses of neurodegenerative disorders and the continued lack of adequate treatment options for brain injuries, stroke, neurodevelopmental disorders, and neuropsychiatric illness. However, new approaches, concurrent with the development of sophisticated bioinformatic and genomic tools, are being used to explore peptide-based therapeutics to manipulate endogenous pathways and targets, including "undruggable" intracellular protein-protein interactions (PPIs). The development of peptide-based therapeutics was previously rejected due to systemic off-target effects and poor bioavailability arising from traditional oral and systemic delivery methods. However, targeted nose-to-brain, or intranasal (IN), approaches have begun to emerge that allow CNS-specific delivery of therapeutics via the trigeminal and olfactory nerve pathways, laying the foundation for improved alternatives to systemic drug delivery. Here we review a dozen promising IN peptide therapeutics in preclinical and clinical development for neurodegenerative (Alzheimer's, Parkinson's), neuropsychiatric (depression, PTSD, schizophrenia), and neurodevelopmental disorders (autism), with insulin, NAP (davunetide), IGF-1, PACAP, NPY, oxytocin, and GLP-1 agonists prominent among them.

Cognitive Deficit in Schizophrenia: From Etiology to Novel Treatments

Schizophrenia is a major mental illness characterized by positive and negative symptoms, and by cognitive deficit. Although cognitive impairment is disabling for patients, it has been largely neglected in the treatment of schizophrenia. There are several reasons for this lack of treatments for cognitive deficit, but the complexity of its etiology-in which neuroanatomic, biochemical and genetic factors concur-has contributed to the lack of effective treatments. In the last few years, there have been several attempts to develop novel drugs for the treatment of cognitive impairment in schizophrenia. Despite these efforts, little progress has been made. The latest findings point to the importance of developing personalized treatments for schizophrenia which enhance neuroplasticity, and of combining pharmacological treatments with non-pharmacological measures.

[An effect of cholinesterase blockade on negative symptoms in schizophrenia]

Abstruct.

OBJECTIVE

To assess the possibilities of influencing the severity of negative disorders in schizophrenic patients with cholinesterase blockade.

MATERIAL AND METHODS

The study included stable 26 patients (13 of them women), average age 40.4 (SD 11.7) with paranoid schizophrenia, episodic form according to ICD-10). All patients received antipsychotic therapy, which was not changed at least for 2 months. We used psychometric scales (Positive and Negative Syndrome Assessment Scale (PANSS), Global Functioning Scale (GAF), neurocognitive techniques (Brief Assessment of Cognition in Schizophrenia-BACS), projective psychological techniques (Rorschach test).

RESULTS AND CONCLUSION

The results of the study showed that augmentation of maintenance antipsychotic therapy with a cholinesterase blocker (ipidacrine at a dose of 20 mg per day) had positive impact on negative symptoms, decreasing the severity of emotional deficiency. The positive changes of cognitive impairment, measured with BACS, occurred regardless of changes in the severity of negative disorders, measured with PANSS. The Rorschach test showed an improvement in the conventional orientation of the patients' thinking. No exacerbation of psychotic symptoms was registered.

Treating disorders across the lifespan by modulating cholinergic signaling with galantamine

Advances in understanding the regulatory functions of the nervous system have revealed neural cholinergic signaling as a key regulator of cytokine responses and inflammation. Cholinergic drugs, including the centrally acting acetylcholinesterase inhibitor, galantamine, which are in clinical use for the treatment of Alzheimer's disease and other neurodegenerative and neuropsychiatric disorders, have been rediscovered as anti-inflammatory agents. Here, we provide a timely update on this active research and clinical developments. We summarize the involvement of cholinergic mechanisms and inflammation in the pathobiology of Alzheimer's disease, Parkinson's disease, and schizophrenia, and the effectiveness of galantamine treatment. We also highlight recent findings demonstrating the effects of galantamine in preclinical and clinical settings of numerous conditions and diseases across the lifespan that are characterized by immunological, neurological, and metabolic dysfunction.

The difference of social cognitive and neurocognitive performance between patients with schizophrenia at different stages and influencing factors

Objects

To explore the specific features of cognitive function in patients with schizophrenia at different stages and its influencing factors.

Methods

The MATRICS Consensus Cognitive Battery (MCCB) and the Brief Psychiatric Rating Scale (BPRS) were administered to 208 patients with schizophrenia, including 158 clinically stable schizophrenia (CSS) and 50 first-episode patients with schizophrenia (FES), and 40 healthy controls (HC). Propensity score matching (PSM) was used to match the CSS and FES.

Results

(1) The MCCB and it^,s sub-scale scores in patients with schizophrenia were lower than HC, but the score of emotion intelligence showed no significant difference between CSS and HC. (2) Before PSM, the cognitive scores of FES were significantly lower than CSS (except trail making A test, Hopkins verbal learning, category fluency). After PSM, patients with CSS still do better in performing trail making A test, emotional intelligence, continuous performances and MCCB total score. (3) BPRS total score, gender, group (FES vs CSS) and age were independent contributors to emotion intelligence, and BPRS total score had the biggest effect. (4) The effect of group (FES vs CSS) on MCCB total score and emotional intelligence was statistically significant.

Conclusions

There are significant cognitive deficits in patients with FES and CSS compared with HC. FES have greater cognitive impairments compared with CSS. Emotion intelligence of CSS may be even close to the level of HC. BPRS total score, gender, group (FES vs CSS) and age may be the independent contributors to social cognition. Group (FES vs CSS) may play an important effect on general cognition and social cognition.

Current perspectives in treating negative symptoms of schizophrenia: A narrative review (Review)

The negative symptoms of schizophrenia are an unmet treatment target as currently approved treatments mostly control positive symptoms. The persistence of these symptoms holds back the patient's reinstatement in society, making them incapable of fulfilling their social, professional, or family roles. There is overwhelming research evidence suggesting that the negative symptoms of schizophrenia are associated with poorer functioning and lower quality of life than positive symptoms, confirming the need for developing new treatments for this particular category of symptoms. This present review aims to review clinical trials addressing novel pharmacological approaches addressing primary negative symptoms of schizophrenia. We overview both monotherapies, first-generation and second-generation antipsychotics, and add-on therapies, including psychostimulants, anti-inflammatory drugs, antidepressants, molecules targeting glutamatergic, cholinergic or serotonergic systems and hormones. Our findings suggest that the primary negative symptoms of schizophrenia may be mitigated by adjunctive therapies, and we highlight the pharmacological agents that have proven superior efficacy. Novel compounds such as cariprazine and MIN-101, to date, show promising results, but large clinical trials are needed to test their efficacy and safety.

Computational Dissociation of Dopaminergic and Cholinergic Effects on Action Selection and Inhibitory Control

BACKGROUND

Patients with schizophrenia make more errors than healthy subjects in the antisaccade task. In this paradigm, participants are required to inhibit a reflexive saccade to a target and to select the correct action (a saccade in the opposite direction). While the precise origin of this deficit is not clear, it has been connected to aberrant dopaminergic and cholinergic neuromodulation.

METHODS

To study the impact of dopamine and acetylcholine on inhibitory control and action selection, we administered two selective drugs (levodopa 200 mg/galantamine 8 mg) to healthy volunteers (N = 100) performing the antisaccade task. The computational model SERIA (stochastic early reaction, inhibition, and late action) was employed to separate the contribution of inhibitory control and action selection to empirical reaction times and error rates.

RESULTS

Modeling suggested that levodopa improved action selection (at the cost of increased reaction times) but did not have a significant effect on inhibitory control. By contrast, according to our model, galantamine affected inhibitory control in a dose-dependent fashion, reducing inhibition failures at low doses and increasing them at higher levels. These effects were sufficiently specific that the computational analysis allowed for identifying the drug administered to an individual with 70% accuracy.

CONCLUSIONS

Our results do not support the hypothesis that elevated tonic dopamine strongly impairs inhibitory control. Rather, levodopa improved the ability to select correct actions. However, inhibitory control was modulated by cholinergic drugs. This approach may provide a starting point for future computational assays that differentiate neuromodulatory abnormalities in heterogeneous diseases like schizophrenia.

The past and future of novel, non-dopamine-2 receptor therapeutics for schizophrenia: A critical and comprehensive review

Since the discovery of chlorpromazine in the 1950's, antipsychotic drugs have been the cornerstone of treatment of schizophrenia, and all attenuate dopamine transmission at the dopamine-2 receptor. Drug development for schizophrenia since that time has led to improvements in side effects and tolerability, and limited improvements in efficacy, with the exception of clozapine. However, the reasons for clozapine's greater efficacy remain unclear, despite the great efforts and resources invested therewith. We performed a comprehensive review of the literature to determine the fate of previously tested, non-dopamine-2 receptor experimental treatments. Overall we included 250 studies in the review from the period 1970 to 2017 including treatments with glutamatergic, serotonergic, cholinergic, neuropeptidergic, hormone-based, dopaminergic, metabolic, vitamin/naturopathic, histaminergic, infection/inflammation-based, and miscellaneous mechanisms. Despite there being several promising targets, such as allosteric modulation of the NMDA and α7 nicotinic receptors, we cannot confidently state that any of the mechanistically novel experimental treatments covered in this review are definitely effective for the treatment of schizophrenia and ready for clinical use. We discuss potential reasons for the relative lack of progress in developing non-dopamine-2 receptor treatments for schizophrenia and provide recommendations for future efforts pursuing novel drug development for schizophrenia.

Cross Cultural Validation and Extension of the Clinical Assessment Interview for Negative Symptoms (CAINS) in the Chinese Context: Evidence from a Spectrum Perspective

The Clinical Assessment Interview for Negative Symptoms (CAINS) was designed in accordance with the recent theory and research in social affective neuroscience and to address the psychometric and conceptual limitations of other instruments assessing negative symptoms. The present study aimed to provide a large-scale validation of the CAINS in China and examine its applicability and validity evidence across the schizophrenia spectrum. Using confirmatory factor analysis, our results replicated the original findings in the US development samples that the CAINS possesses a stable 2-factor structure, namely "motivation/pleasure" and "expression". We also found significant correlations between the CAINS and other negative symptom measures. The CAINS demonstrated good discriminant validity in differentiating negative symptoms in people with schizophrenia, nonpsychotic first-degree relatives and people with social anhedonia. People with schizophrenia exhibited significantly higher CAINS subscale scores than first-degree relatives and healthy controls. In addition, first-degree relatives had higher "motivation/pleasure" scores than healthy controls. The "motivation/pleasure" subscale scores of individuals with social anhedonia were also significantly higher than healthy controls.

Kynurenic Acid in Schizophrenia: A Systematic Review and Meta-analysis

Kynurenic acid (KYNA) is an endogenous antagonist of N-methyl-D-aspartate and α7 nicotinic acetylcholine receptors that is derived from astrocytes as part of the kynurenine pathway of tryptophan degradation. Evidence suggests that abnormal KYNA levels are involved in the pathophysiology of schizophrenia. However, this has never been assessed through a meta-analysis. A literature search was conducted through Ovid using Embase, Medline, and PsycINFO databases (last search: December 2016) with the search terms: (kynuren* or KYNA) and (schizophreni* or psychosis). English language studies measuring KYNA levels using any method in patients with schizophrenia and healthy controls (HCs) were identified. Standardized mean differences (SMDs) were calculated to determine differences in KYNA levels between groups. Subgroup analyses were separately performed for nonoverlapping participant samples, KYNA measurement techniques, and KYNA sample source. The influences of patients' age, antipsychotic status (%medicated), and sex (%male) on study SMDs were assessed through a meta-regression. Thirteen studies were deemed eligible for inclusion in the meta-analysis. In the main analysis, KYNA levels were elevated in the patient group. Subgroup analyses demonstrated that KYNA levels were increased in nonoverlapping participant samples, and centrally (cerebrospinal fluid and brain tissue) but not peripherally. Patients' age, %medicated, and %male were each positively associated with study SMDs. Overall, KYNA levels are increased in patients with schizophrenia, specifically within the central nervous system. An improved understanding of KYNA in patients with schizophrenia may contribute to the development of novel diagnostic approaches and therapeutic strategies.

[Negative symptoms in schizophrenia: psychotherapeutic approaches]

Although negative symptoms are recognized as a central feature of schizophrenia, their definition as well as phenomenology have long been a vexing issue. During these last years, a major progress has been made with the delineation of two underlying subdomains of negative symptoms: diminished expression and anhedonia-avolition-apathy. As current guidelines are not always in accord on the efficacy of treatments on negative symptoms, it may be tempting to re-interpret the findings of clinical trials by looking at the effects of treatments on these two subdomains. This could concern both psychotropic treatments and psychotherapeutic interventions. Furthermore, neuroimaging as well as emotional response studies have permitted to better understand the mechanism which could be at the root of diminished expression and anhedonia in schizophrenia. On this basis, new psychotherapeutic methods have been devised which, by specifically targeting these two subdomains, are likely to be more efficient on negative symptoms. Further research is warranted to test their efficacy in randomized controlled trials.

Negative Symptoms in Schizophrenia: Where We have been and Where We are Heading

This review traces the history of negative symptom profiles in neuropsychiatry from their earliest emergence in the 19th century to the current psychiatric concepts and therapeutic approaches. Recent investigations performing exploratory and confirmatory factor analysis have suggested that negative symptoms are multidimensional, including evidence for at least two distinct negative symptom subdomains: diminished expression and amotivation. Preliminary studies have demonstrated the clinical validity of this distinction. Several potential pathophysiological validating factors based on brain imaging analysis of emotional experiences and expressions in individuals with schizophrenia are examined. Finally, the potential of different treatment strategies, including medications and various psychotherapeutic techniques, to most favorably treat each of these subdomains is discussed.

Pharmacological approaches to treating negative symptoms: a review of clinical trials

Clinical trials of pharmacological agents targeting negative symptoms in schizophrenia are reviewed. The focus is on trials that occurred in patients who were stable on an antipsychotic medication at entry to the trial. A small number of trials compared antipsychotics as monotherapy for negative symptoms. Although the data supporting amisulpride for negative symptoms is promising the trials have limitations and it is plausible that the advantages of amisulpride over placebo may result from effects on secondary negative symptoms. Among available agents, antidepressant medications may have effects in negative symptoms. Other promising agents include minocycline, glutamatergic agents, and alpha-7 nicotinic agents. More than 15 active trials are currently underway to evaluate new treatments for negative symptoms.

Targeting alpha-7 nicotinic neurotransmission in schizophrenia: a novel agonist strategy

Alpha7 nicotinic acetylcholine receptor (α7 nAChR) agonists may be valuable treatments for negative symptoms and cognitive impairment in schizophrenia. Unfortunately, chronic exposure to an agonist may reduce the receptor's sensitivity. Therefore, we combined CDP-choline, a dietary source of the direct agonist choline, with galantamine, a positive allosteric modulator (PAM) of nicotinic acetylcholine receptors, to improve the efficiency of transducing the choline signal and, possibly, preserve the receptor in a sensitive state. We conducted a single-site, double-blind randomized clinical trial comparing galantamine/CDP-choline to placebos in schizophrenia patients with negative symptoms who were receiving second generation antipsychotics. Forty-three subjects received galantamine and CDP-choline or matching placebos for 16weeks. The primary outcome measure was the 5-item Marder negative-symptoms factor of the Positive and Negative Syndrome Scale (PANSS). Cognition and functioning were also assessed. Trial completion was high; 79%. There was no significant treatment effect on negative symptoms, other PANSS symptom factors, or the MATRICS Cognitive Consensus Battery. There were significant treatment effects in overall functioning and a test of free verbal recall. Three subjects discontinued treatment in the active treatment group for gastro-intestinal adverse events (AE). The most common AE for galantamine/CDP-choline was abdominal pain; for placebo it was headache and sweating. Although there was no significant treatment effect on negative symptoms, the direction of effect mirrored the effects on a cognitive measure and overall functioning. Further study of α7 nAChR agonist/PAMs is warranted in larger studies that will have greater power.

Pharmacological treatment of schizophrenia: a critical review of the pharmacology and clinical effects of current and future therapeutic agents

Since the introduction of chlorpromazine and throughout the development of the new-generation antipsychotic drugs (APDs) beginning with clozapine, the D(2) receptor has been the target for the development of APDs. Pharmacologic actions to reduce neurotransmission through the D(2) receptor have been the only proven therapeutic mechanism for psychoses. A number of novel non-D(2) mechanisms of action of APDs have been explored over the past 40 years but none has definitively been proven effective. At the same time, the effectiveness of treatments and range of outcomes for patients are far from satisfactory. The relative success of antipsychotics in treating positive symptoms is limited by the fact that a substantial number of patients are refractory to current medications and by their lack of efficacy for negative and cognitive symptoms, which often determine the level of functional impairment. In addition, while the newer antipsychotics produce fewer motor side effects, safety and tolerability concerns about weight gain and endocrinopathies have emerged. Consequently, there is an urgent need for more effective and better-tolerated antipsychotic agents, and to identify new molecular targets and develop mechanistically novel compounds that can address the various symptom dimensions of schizophrenia. In recent years, a variety of new experimental pharmacological approaches have emerged, including compounds acting on targets other than the dopamine D(2) receptor. However, there is still an ongoing debate as to whether drugs selective for singe molecular targets (that is, 'magic bullets') or drugs selectively non-selective for several molecular targets (that is, 'magic shotguns', 'multifunctional drugs' or 'intramolecular polypharmacy') will lead to more effective new medications for schizophrenia. In this context, current and future drug development strategies can be seen to fall into three categories: (1) refinement of precedented mechanisms of action to provide drugs of comparable or superior efficacy and side-effect profiles to existing APDs; (2) development of novel (and presumably non-D(2)) mechanism APDs; (3) development of compounds to be used as adjuncts to APDs to augment efficacy by targeting specific symptom dimensions of schizophrenia and particularly those not responsive to traditional APD treatment. In addition, efforts are being made to determine if the products of susceptibility genes in schizophrenia, identified by genetic linkage and association studies, may be viable targets for drug development. Finally, a focus on early detection and early intervention aimed at halting or reversing progressive pathophysiological processes in schizophrenia has gained great influence. This has encouraged future drug development and therapeutic strategies that are neuroprotective. This article provides an update and critical review of the pharmacology and clinical profiles of current APDs and drugs acting on novel targets with potential to be therapeutic agents in the future.

Dipyridamole monotherapy in schizophrenia: pilot of a novel treatment approach by modulation of purinergic signaling

BACKGROUND

Emerging data indicate the neuromodulator adenosine may play a role in the therapeutics of schizophrenia. Adenosine A(2A) receptor stimulation exerts a functional antagonism at postsynaptic D(2) receptors. Data from animal models relevant to schizophrenia support a therapeutic effect of modulating adenosinergic transmission in the ventral striatum. One previous clinical trial showed superiority of adjunctive dipyridamole, an adenosine reuptake inhibitor, compared to placebo in ameliorating positive symptoms in schizophrenia patients.

OBJECTIVES

The aim of this study was to examine the effects of dipyridamole monotherapy of 200 mg/day on positive and negative symptoms, with the goal of determining dosing for future adjunctive studies in schizophrenia.

METHODS

Twenty symptomatic schizophrenia participants were randomized to a 6-week double-blind trial comparing olanzapine (20 mg/day) to dipyridamole monotherapy (200 mg/day). Thirteen participants completed the treatment phase (eight on dipyridamole; five on olanzapine).

RESULTS

The olanzapine group showed a trend (p = 0.08) for superiority on BPRS total scores (mean ± SD: total BPRS score decreasing from 36.8 ± 2.3 at week 1, to 33.2 ± 5.5 at the end of the study). The mean total BPRS scores decreased from 36.4 ± 5.3 to 34.0 ± 7.7 in the dipyridamole group.

CONCLUSIONS

Although these pilot data do not support a significant antipsychotic effect of dipyridamole monotherapy, the results provide some evidence for examining dipyridamole (200 mg/day) as adjunct to symptomatic antipsychotic-treated schizophrenia patients.

Effects of adjunct galantamine to risperidone, or haloperidol, in animal models of antipsychotic activity and extrapyramidal side-effect liability: involvement of the cholinergic muscarinic receptor

The acetylcholine esterase inhibitor/cholinergic nicotinic receptor (nAChR) allosteric modulator galantamine (Gal) is used against cognitive impairment in Alzheimer's disease. Negative/cognitive and psychotic symptom improvement in schizophrenia by adjunct Gal to antipsychotic drugs (APDs) has been reported. Cognitive symptoms in schizophrenia may involve brain prefrontal hypo-dopaminergia. Experimental data by others indicate nAChR involvement in animal pro-cognitive effects of Gal. The role of nAChRs in antipsychotic effects by Gal has, however, not been elucidated. Using the conditioned avoidance response (CAR) and the catalepsy tests for antipsychotic activity and extrapyramidal side-effect (EPS) liability, respectively, we here investigated the effects of adjunct Gal (1.25 mg/kg) to the typical APD haloperidol (Hal) (0.05 mg/kg), or the atypical APD risperidone (Ris) (0.2 mg/kg), in rats. Adjunct Gal significantly enhanced APD-like effects by low doses of Hal or Ris, but showed a safe EPS liability profile only in combination with Ris. Pretreatment with the muscarinic receptor (mAChR) antagonist scopolamine, but not the nAChR antagonist mecamylamine, completely reversed the enhancing effects of adjunct Gal to Hal treatment, in the CAR test. While the nAChR-modulating properties of Gal probably contribute to pro-cognitive activity, as shown by others, the present data suggest that any contribution to antipsychotic activity by Gal is mediated primarily via mAChRs. This property combination of Gal may offer a unique, favourable therapeutic profile for schizophrenia treatment.

Emerging drugs for schizophrenia

INTRODUCTION

Since the development of clozapine, scores of antipsychotics have been introduced. These are, with one exception (aripiprazole), based on the pharmacological principle of 5-HT(2)/dopamine antagonism. Research on other treatment targets, which, in part, influence dopaminergic pathways directly or indirectly, is mounting. Managing psychotic symptoms is only one facet of successful treatment of schizophrenia. Effective remedies against negative symptoms and cognitive deficits are still an unmet clinical need.

AREAS COVERED

With the focus on the topics mentioned above, the authors briefly review the latest clinical research organized on the basis of receptor systems and other drug targets, which are discussed to be involved in the pathophysiology of schizophrenia.

EXPERT OPINION

In conclusion, although clinicians will have to have considerable patience before truly novel anti-schizophrenia treatments become obtainable, a number of interesting leads with considerable theoretical potential are being explored. As yet, it is difficult to predict which of these mechanisms will effectively augment the currently available treatments.

Evidence-based guidelines for the pharmacological treatment of schizophrenia: recommendations from the British Association for Psychopharmacology

These guidelines from the British Association for Psychopharmacology address the scope and targets of pharmacological treatment for schizophrenia. A consensus meeting, involving experts in schizophrenia and its treatment, reviewed key areas and considered the strength of evidence and clinical implications. The guidelines were drawn up after extensive feedback from the participants and interested parties, and cover the pharmacological management and treatment of schizophrenia across the various stages of the illness, including first-episode, relapse prevention, and illness that has proved refractory to standard treatment. The practice recommendations presented are based on the available evidence to date, and seek to clarify which interventions are of proven benefit. It is hoped that the recommendations will help to inform clinical decision making for practitioners, and perhaps also serve as a source of information for patients and carers. They are accompanied by a more detailed qualitative review of the available evidence. The strength of supporting evidence for each recommendation is rated.

Assessment of pharmacotherapy for negative symptoms of schizophrenia

Negative symptoms in schizophrenia include diminished ability to communicate, motivate, and socialize as potentially debilitating aspects of the illness that are associated with long-term impairment. Despite such burden, the domain has been underrepresented in drug development and treatment research. In this article, we review research regarding pharmacotherapy for negative symptoms, with a focus on studies published during the past 2 years. Clearly positive studies were limited to N-methyl-D-aspartate agonists, while antipsychotics and antidepressants did not show substantial benefit, and cognitive enhancers have yielded mixed results. Proof-of-concept studies of other agents such as minocycline and omega fatty acids yielded promising, albeit preliminary findings that warrant replication. Study outcomes and designs are discussed along with implications for future research.

Smoking, nicotine and neuropsychiatric disorders

Tobacco smoking is an extremely addictive and harmful form of nicotine (NIC) consumption, but unfortunately also the most prevalent. Although disproportionately high frequencies of smoking and its health consequences among psychiatric patients are widely known, the neurobiological background of this epidemiological association is still obscure. The diverse neuroactive effects of NIC and some other major tobacco smoke constituents in the central nervous system may underlie this association. This present paper summarizes the pharmacology of NIC and its receptors (nAChR) based on a systematic review of the literature. The role of the brain's reward system(s) in NIC addiction and the results of functional and structural neuroimaging studies on smoking-related states and behaviors (i.e. dependence, craving, withdrawal) are also discussed. In addition, the epidemiological, neurobiological, and genetic aspects of smoking in several specific neuropsychiatric disorders are reviewed and the clinical relevance of smoking in these disease states addressed.

Lack of beneficial galantamine effect for smoking behavior: a double-blind randomized trial in people with schizophrenia

Cigarette smoking is in schizophrenia is prevalent and may be due to self-medicating attempts to improve cognitive deficits related to alpha7 and alpha4beta2 nicotinic receptor dysregulation. Galantamine is an acetylcholinesterase inhibitor that acts as a positive allosteric modulator of nicotine acetylcholine receptors including both the alpha4beta2 and alpha7 subunits. In a double-blind randomized clinical trial galantamine was compared to placebo for its effects on cognitive functioning in people with schizophrenia. This manuscript reports findings for galantamine's effect on smoking behavior in people from this 12-week trial who were smokers (18 galantamine, 25 placebo). Expired CO was measured every 2 weeks and the Fagerström Test for Nicotine Dependence (FTND) was administered at baseline and endpoint. Expired CO measures in galantamine subjects were 23.0+/-9.7 ppm and 21.1+/-10.3 ppm at baseline and Week 12, respectively, compared to 20.1+/-8.5 ppm and 21.0+/-10.3 ppm at baseline and Week 12 in placebo subjects. The mean tau-b correlation between expired CO level and visit was -0.05+/-0.41 in the galantamine group and 0.13+/-0.42 in the placebo group (F=0.73, df=1,38, p=0.40), suggesting that there were no trends toward increased or decreased smoking in either group. Mean FTND scores in the galantamine group were 4.9+/-2.5 at baseline and 5.2+/-2.2 at Week 12, compared to 4.1+/-2.6 at baseline and 3.7+/-2.6 at Week 12 in the placebo group (Mantel-Haenszel chi2=5.53, df=1, p=0.019), for an effect size of 0.4. These results suggest that galantamine has no effect on cigarette smoking and that during galantamine treatment nicotine dependency scores worsen.