Smoking and movement disorders in psychiatric patients

Assessment of Extrapyramidal Symptoms Associated with Psychotropics Pharmacological Treatments, and Associated Risk Factors

BACKGROUND

Extrapyramidal Symptoms (EPS) are unwanted symptoms commonly originating from the use of certain medications. The symptoms can range from minimal discomfort to permanent involuntary muscular movements. The aims of the study were to examine the incidence of drug-induced extrapyramidal symptoms (di-EPS), associated risk factors, and clinical characteristics.

METHODS

This is a retrospective, observational study of di-EPS conducted in outpatient clinics of Jordan using the longitudinal health database (Hakeem®) for data collection. Patients who received drugs with the risk of EPS during the period 2010-2020 were included and followed. Patients with any of the known underlying conditions that may cause EPS or were currently taking drugs that may mask the symptoms were excluded. Gender and age-matched control subjects were included in the study. The Statistical Package for Social Science (SPSS®) version 26 was used for data analysis.

RESULTS

The final dataset included 34898 exposed patients and 69796 matched controls. The incidence of di-EPS ranged from 9.8% [Amitriptyline 25mg] to 28.9% (Imipramine 25mg). Baseline factors associated with a significantly higher risk of developing di-EPS were age {HR: 1.1 [95%CI: 0.8-1.2, p=0.003], smoking {HR: 1.7 (95%CI: 1.3-2.2), p=0.02}, tremor history {HR: 7.4 (95%CI: 5.9-8.3), p=.002} and history of taking antipsychotics {HR: 3.9, (95% CI: 2.5-4.6), p=0.001}. Patients taking paroxetine {HR: 8.6 [95%CI: 7.4-9.8], p=.0002},imipramine {HR: 8.3, [7.1-10.5], p=0.01}, or fluoxetine {HR: 8.2 (95%CI: 6.8-9.3), p=.006} had a significantly higher risk of developing di-EPS compared to patients taking citalopram. Myoclonus, blepharospasm, symptoms of the basal ganglia dysfunction, and organic writers' cramp were reported among participants.

CONCLUSION

Patients treated with paroxetine, imipramine, fluoxetine, or clomipramine had a higher risk of developing di-EPS than patients treated with citalopram. The difference in gender was not significantly related to di-EPS development. Whereas age, smoking, and history of taking antipsychotics were significantly associated with di-EPS development.

KEY FINDINGS

• High incidence of drug-induced extrapyramidal symptoms (di-EPS) was reported• Age, smoking, tremor history, and history of taking antipsychotics were risk factors of drug-induced extrapyramidal symptoms.• Patients taking paroxetine, imipramine or fluoxetine had a significantly higher risk of developing di-EPS compared to patients taking citalopram.

Does the degree of smoking effect the severity of tardive dyskinesia? A longitudinal clinical trial

Background

Tardive dyskinesia (TD) is a movement disorder observed after chronic neuroleptic treatment. Smoking is presumed to increase the prevalence of TD. The question of a cause-effect-relationship between smoking and TD, however, remains to be answered. Purpose of this study was to examine the correlation between the degree of smoking and the severity of TD with respect to differences caused by medication.

Method

We examined 60 patients suffering from schizophrenia and TD. We compared a clozapine-treated group with a group treated with typical neuroleptics. Movement disorders were assessed using the Abnormal-Involuntary-Movement-Scale and the technical device digital image processing, providing rater independent information on perioral movements.

Results

We found a strong correlation (.80 < r < .90, always p < .0001) between the degree of smoking and severity of TD. Repeated measurements revealed a positive correlation between changes in cigarette consumption and changes of the severity of TD (p < .0001). Analyses of covariance indicated a significant group-effect with a lower severity of TD in the clozapine-group compared to the typical-neuroleptics-group (p = .010). Interaction-analyses indicated a higher impact of smoking on the severity of TD in the typical-neuroleptics-group compared to the clozapine-group (p = .033).

Conclusion

Concerning a possible cause-effect-relationship between smoking and TD, smoking is more of a general health hazard than neuroleptic exposure in terms of TD.

Potential Therapeutic Application for Nicotinic Receptor Drugs in Movement Disorders

Emerging studies indicate that striatal cholinergic interneurons play an important role in synaptic plasticity and motor control under normal physiological conditions, while their disruption may lead to movement disorders. Here we discuss the involvement of the cholinergic system in motor dysfunction, with a focus on the role of the nicotinic cholinergic system in Parkinson's disease and drug-induced dyskinesias. Evidence for a role for the striatal nicotinic cholinergic system stems from studies showing that administration of nicotine or nicotinic receptor drugs protects against nigrostriatal degeneration and decreases L-dopa-induced dyskinesias. In addition, nicotinic receptor drugs may ameliorate tardive dyskinesia, Tourette's syndrome and ataxia, although further study is required to understand their full potential in the treatment of these disorders. A role for the striatal muscarinic cholinergic system in movement disorders stems from studies showing that muscarinic receptor drugs acutely improve Parkinson's disease motor symptoms, and may reduce dyskinesias and dystonia. Selective stimulation or lesioning of striatal cholinergic interneurons suggests they are primary players in this regulation, although multiple central nervous systems appear to be involved.

IMPLICATIONS

Accumulating data from preclinical studies and clinical trials suggest that drugs targeting CNS cholinergic systems may be useful for symptomatic treatment of movement disorders. Nicotinic cholinergic drugs, including nicotine and selective nAChR receptor agonists, reduce L-dopa-induced dyskinesias, as well as antipsychotic-induced tardive dyskinesia, and may be useful in Tourette's syndrome and ataxia. Subtype selective muscarinic cholinergic drugs may also provide effective therapies for Parkinson's disease, dyskinesias and dystonia. Continued studies/trials will help address this important issue.

Cigarette smoking and schizophrenia

It has been recognised for many years that patients with psychiatric illnesses, especially schizophrenia, smoke to excess. However, recently there has been a resurgence of interest in the high prevalence of nicotine addiction in patients with schizophrenia. It has become increasingly clear that heavy cigarette smoking is intimately associated with the schizophrenic illness and that this may have implications for the underlying neurobiology of schizophrenia.

Cigarette smoking and schizophrenia: a specific clinical and therapeutic profile? Results from the FACE-Schizophrenia cohort

BACKGROUND

Tobacco use is common in patients with schizophrenia (SZ) but little is known on the role of tobacco in the physiopathology or on the course of the disease. Only few studies embrace an extensive examination of clinical and therapeutic characteristics in stabilized patients. The objective of the present study was to determine the prevalence of tobacco smoking in stabilized SZ outpatients and the clinical and treatment characteristics associated with daily tobacco use in a large community-dwelling sample of patients.

METHODS

Three-hundred-and-sixty-one patients were included in the network of the FondaMental Expert Centers for Schizophrenia. Current tobacco status was self-declared.

RESULTS

53.7% were smokers. Mean age at tobacco onset was 17.2years old. In multivariate analyses, after adjustment for confounding factors, positive symptoms and mean daily antipsychotic dose were associated with a higher frequency of tobacco use (OR=1.06 95%IC[1.02-1.12], for positive symptoms, OR=1.1, 95%IC[1.02-1.18] for daily antipsychotic dose). Education level, negative symptoms, anticholinergic agents, clozapine or aripiprazole administration were independently associated with a lower frequency of tobacco use (respectively OR=0.87, 95%IC [0.79, 0.95], OR=0.95, 95%IC[0.91-0.98], OR=0.41, 95%IC[0.22-0.76], OR=0.56, 95%IC=[0.32, 0.99] and OR=0.49, 95%IC [0.26-0.91]).

CONCLUSION

The prevalence of current tobacco smoking in a French community-dwelling SZ patients is higher that observed in the general population. Patients with tobacco use present clinical and therapeutic specificities that may involve interaction between cholinergic-nicotinic and dopaminergic systems. The present study suggests that some therapeutics may improve daily smoking behavior in smokers. These results should be confirmed in longitudinal studies.

Antipsychotic-induced Tardive dyskinesia: from biological basis to clinical management

INTRODUCTION

Tardive dyskinesia (TD) is a chronic and disabling movement disorder with a complex pathophysiological basis. A significant percentage of patients does not receive correct diagnosis, resulting in delayed or inaccurate treatment and poor outcome. Therefore, there is a critical need for prompt recognition, implementation of efficacious treatment regimens and long-term follow up of patients with TD. Areas covered: The current paper provides an overview of emerging data concerning proposed pathophysiology theories, epidemiology, risk factors, and therapeutic strategies for TD. Expert commentary: Despite considerable research efforts, TD remains a challenge in the treatment of psychosis as the available strategies remain sub-optimal. The best scenario will always be the prophylaxis or prevention of TD, which entails limiting the use of antipsychotics.

Chronic Nicotine Mitigates Aberrant Inhibitory Motor Learning Induced by Motor Experience under Dopamine Deficiency

Although dopamine receptor antagonism has long been associated with impairments in motor performance, more recent studies have shown that dopamine D2 receptor (D2R) antagonism, paired with a motor task, not only impairs motor performance concomitant with the pharmacodynamics of the drug, but also impairs future motor performance once antagonism has been relieved. We have termed this phenomenon "aberrant motor learning" and have suggested that it may contribute to motor symptoms in movement disorders such as Parkinson's disease (PD). Here, we show that chronic nicotine (cNIC), but not acute nicotine, treatment mitigates the acquisition of D2R-antagonist-induced aberrant motor learning in mice. Although cNIC mitigates D2R-mediated aberrant motor learning, cNIC has no effect on D1R-mediated motor learning. β2-containing nicotinic receptors in dopamine neurons likely mediate the protective effect of cNIC against aberrant motor learning, because selective deletion of β2 nicotinic subunits in dopamine neurons reduced D2R-mediated aberrant motor learning. Finally, both cNIC treatment and β2 subunit deletion blunted postsynaptic responses to D2R antagonism. These results suggest that a chronic decrease in function or a downregulation of β2-containing nicotinic receptors protects the striatal network against aberrant plasticity and aberrant motor learning induced by motor experience under dopamine deficiency.

SIGNIFICANCE STATEMENT

Increasingly, aberrant plasticity and aberrant learning are recognized as contributing to the development and progression of movement disorders. Here, we show that chronic nicotine (cNIC) treatment or specific deletion of β2 nicotinic receptor subunits in dopamine neurons mitigates aberrant motor learning induced by dopamine D2 receptor (D2R) blockade in mice. Moreover, both manipulations also reduced striatal dopamine release and blunt postsynaptic responses to D2R antagonists. These results suggest that chronic downregulation of function and/or receptor expression of β2-containing nicotinic receptors alters presynaptic and postsynaptic striatal signaling to protect against aberrant motor learning. Moreover, these results suggest that cNIC treatment may alleviate motor symptoms and/or delay the deterioration of motor function in movement disorders by blocking aberrant motor learning.

Nicotinic receptor contributions to smoking: insights from human studies and animal models

It is becoming increasingly evident that a variety of factors contribute to smoking behavior. Nicotine is a constituent of tobacco smoke that exerts its psychoactive effects via binding to nicotinic acetylcholine receptors (nAChRs) in brain. Human genetic studies have identified polymorphisms in nAChR genes, which predict vulnerability to risk for tobacco dependence. In vitro studies and animal models have identified the functional relevance of specific polymorphisms. Together with animal behavioral models, which parse behaviors believed to contribute to tobacco use in humans, these studies demonstrate that nicotine action at a diversity of nAChRs is important for expression of independent behavioral phenotypes, which support smoking behavior.

Role for the nicotinic cholinergic system in movement disorders; therapeutic implications

A large body of evidence using experimental animal models shows that the nicotinic cholinergic system is involved in the control of movement under physiological conditions. This work raised the question whether dysregulation of this system may contribute to motor dysfunction and whether drugs targeting nicotinic acetylcholine receptors (nAChRs) may be of therapeutic benefit in movement disorders. Accumulating preclinical studies now show that drugs acting at nAChRs improve drug-induced dyskinesias. The general nAChR agonist nicotine, as well as several nAChR agonists (varenicline, ABT-089 and ABT-894), reduces l-dopa-induced abnormal involuntary movements or dyskinesias up to 60% in parkinsonian nonhuman primates and rodents. These dyskinesias are potentially debilitating abnormal involuntary movements that arise as a complication of l-dopa therapy for Parkinson's disease. In addition, nicotine and varenicline decrease antipsychotic-induced abnormal involuntary movements in rodent models of tardive dyskinesia. Antipsychotic-induced dyskinesias frequently arise as a side effect of chronic drug treatment for schizophrenia, psychosis and other psychiatric disorders. Preclinical and clinical studies also show that the nAChR agonist varenicline improves balance and coordination in various ataxias. Lastly, nicotine has been reported to attenuate the dyskinetic symptoms of Tourette's disorder. Several nAChR subtypes appear to be involved in these beneficial effects of nicotine and nAChR drugs including α4β2*, α6β2* and α7 nAChRs (the asterisk indicates the possible presence of other subunits in the receptor). Overall, the above findings, coupled with nicotine's neuroprotective effects, suggest that nAChR drugs have potential for future drug development for movement disorders.

Cigarette smoking in outpatients with chronic schizophrenia in Taiwan: relationships to socio-demographic and clinical characteristics

In individuals with schizophrenia, the prevalence of cigarette smoking is significantly higher than that of the general population; this appears to be associated with specific psychosocial and clinical characteristics. Indeed, some evidence suggests an increased risk of suicide among smokers with schizophrenia. The purpose of this study was to examine the characteristics of smokers with schizophrenia in Taiwan. In this cross-sectional study, 95 outpatients with DSM-IV diagnosis of schizophrenia were recruited and independently interviewed for nicotine dependency with tobacco use. The effects of cigarette smoking on the various measures, especially suicidality, were investigated. The results revealed that smokers with schizophrenia had higher rates of hospitalization, lifetime suicide attempts, antipsychotic treatment side effects, psychopathology, impulsivity, depression, anxiety, and suicidal risk than non-smokers with schizophrenia. When separate analyses were conducted in male and female patients, depressive symptoms were significant predictors of suicidality among males, whereas heavy smoking, anxious symptoms, and hopelessness were significant predictors among females. From this study, we may gain insights into the role of cigarette smoking in patients of schizophrenia in Taiwan. Furthermore, cigarette smoking may influence aspects of suicidality in schizophrenia.

Nicotine reduces antipsychotic-induced orofacial dyskinesia in rats

Antipsychotics are an important class of drugs for the management of schizophrenia and other psychotic disorders. They act by blocking dopamine receptors; however, because these receptors are present throughout the brain, prolonged antipsychotic use also leads to serious side effects. These include tardive dyskinesia, repetitive abnormal involuntary movements of the face and limbs for which there is little treatment. In this study, we investigated whether nicotine administration could reduce tardive dyskinesia because nicotine attenuates other drug-induced abnormal movements. We used a well established model of tardive dyskinesia in which rats injected with the commonly used antipsychotic haloperidol develop vacuous chewing movements (VCMs) that resemble human orofacial dyskinesias. Rats were first administered nicotine (minipump; 2 mg/kg per day). Two weeks later, they were given haloperidol (1 mg/kg s.c.) once daily. Nicotine treatment reduced haloperidol-induced VCMs by ∼20% after 5 weeks, with a significant ∼60% decline after 13 weeks. There was no worsening of haloperidol-induced catalepsy. To understand the molecular basis for this improvement, we measured the striatal dopamine transporter and nicotinic acetylcholine receptors (nAChRs). Both haloperidol and nicotine treatment decreased the transporter and α6β2* nAChRs (the asterisk indicates the possible presence of other nicotinic subunits in the receptor complex) when given alone, with no further decline with combined drug treatment. By contrast, nicotine alone increased, while haloperidol reduced α4β2* nAChRs in both vehicle and haloperidol-treated rats. These data suggest that molecular mechanisms other than those directly linked to the transporter and nAChRs underlie the nicotine-mediated improvement in haloperidol-induced VCMs in rats. The present results are the first to suggest that nicotine may be useful for improving the tardive dyskinesia associated with antipsychotic use.

Smoking and tardive dyskinesia in male patients with chronic schizophrenia

Interactions between smoking and movement disorders include the contrasting associations of more cigarette smoking with reductions in Parkinson's disease and increases in tardive dyskinesia (TD) symptoms. Here we examine the relationship between smoking and TD in a large sample of inpatients with schizophrenia. We used cross-sectional naturalistic methods to analyze the prevalence and severity of neuroleptic-induced TD in relation to cigarette smoking among 764 male chronic and medicated inpatients meeting DSM-IV criteria for schizophrenia. We administered a detailed questionnaire including general information, medical and psychological conditions, and smoking behaviors. We evaluated TD severity using the abnormal involuntary movement scale (AIMS) and psychopathology using the Positive and Negative Syndrome Scale (PANSS). The main statistical analyses used cross-tabulations for the prevalence of TD by smoking and multivariate regression analyses for continuous measures (AIMS and PANSS). We found that the prevalence of TD did not significantly differ between smokers (41%=237/578) and non-smokers (37%=69/186). Secondary outcomes showed a significant association between the AIMS total score and age, duration of illness and hospitalization times. Thus, smoking was not associated with TD in male Chinese schizophrenics, but consistent with previous reports, older patients with a longer duration of illness and more hospitalizations showed greater severity of TD.

DPP6 as a candidate gene for neuroleptic-induced tardive dyskinesia

We implemented a two-step approach to detect potential predictor gene variants for neuroleptic-induced tardive dyskinesia (TD) in schizophrenic subjects. First, we screened associations by using a genome-wide (Illumina HumanHapCNV370) SNP array in 61 Japanese schizophrenia patients with treatment-resistant TD and 61 Japanese schizophrenia patients without TD. Next, we performed a replication analysis in 36 treatment-resistant TD and 138 non-TD subjects. An association of an SNP in the DPP6 (dipeptidyl peptidase-like protein-6) gene, rs6977820, the most promising association identified by the screen, was significant in the replication sample (allelic P=0.008 in the replication sample, allelic P=4.6 × 10(-6), odds ratio 2.32 in the combined sample). The SNP is located in intron-1 of the DPP6 gene and the risk allele was associated with decreased DPP6 gene expression in the human postmortem prefrontal cortex. Chronic administration of haloperidol increased Dpp6 expression in mouse brains. DPP6 is an auxiliary subunit of Kv4 and regulates the properties of Kv4, which regulates the activity of dopaminergic neurons. The findings of this study indicate that an altered response of Kv4/DPP6 to long-term neuroleptic administration is involved in neuroleptic-induced TD.

Smoking rates among schizophrenia patients in Japan

According to the meta-analysis performed by de Leon and Diaz, the smoking rate was higher among schizophrenia patients than in the general population with the exception of the populations of Japan and Colombia. The purpose of this study was to reexamine the association between schizophrenia and smoking among Japanese schizophrenia patients using objective measures. The sample comprised 172 schizophrenia inpatients (mean age: 54years; 55% male). Participants were asked by a psychiatrist whether they currently smoked, and their answers were confirmed by the Fagerström Test for Nicotine Dependence and a measurement of the carbon monoxide level in expired air. Data on 7496 Japanese people obtained from the national survey of health were used as the control group. Seventy schizophrenia patients (40.7%) were identified as smokers; the smoking rate was higher among men in their 50s (66.7%) and among women in their 40s (54.6%). The smoking rate was 24.2% in the control group, and multiple logistic regression analysis showed that this percentage was significantly higher in the schizophrenia than in the control group (odds ratio: 2.17), adjusting for sex and age. The association between smoking rate and schizophrenia is consistent across countries, including Japan.

The catechol-O-methyl-transferase gene in tardive dyskinesia

Tardive dyskinesia (TD) is a severe and potentially irreversible motor side effect linked to long-term antipsychotic exposure. Changes in dopamine neurotransmission have been implicated in the etiology of TD, and catechol-O-methyl-transferase (COMT) is an enzyme that metabolizes dopamine.

OBJECTIVES

We investigated five single-nucleotide polymorphisms in addition to the functional Val158Met variant spanning the COMT gene for association with TD.

METHODS

We analyzed the six COMT single-nucleotide polymorphisms in a sample of schizophrenia/schizoaffective disorder patients (n=226; 196 Caucasians and 30 African Americans).

RESULTS

We found a significant association between the marker rs165599 in the 3' untranslated region of COMT and TD (AA versus G-carrier: OR(AA)=2.22, 95% CI:1.23-4.03; P=0.007). The association appeared to be originating from males. We did not find a significant association of the other five tested polymorphisms with TD in our samples. We performed a sex-stratified meta-analysis across all of the published studies (n=6 plus our own data) of COMT and TD, and found an association between ValVal genotype and TD in females (OR(ValVal)=1.63, 95% CI: 1.09-2.45; P=0.019) but not in males.

CONCLUSIONS

Overall, our results suggest that the COMT gene may have a minor but consistent role in TD, although sex-stratified studies with additional markers in larger clinical samples should be performed.

Association of the HSPG2 gene with neuroleptic-induced tardive dyskinesia

Tardive dyskinesia (TD) is characterized by repetitive, involuntary, and purposeless movements that develop in patients treated with long-term dopaminergic antagonists, usually antipsychotics. By a genome-wide association screening of TD in 50 Japanese schizophrenia patients with treatment-resistant TD and 50 Japanese schizophrenia patients without TD (non-TD group) and subsequent confirmation in independent samples of 36 treatment-resistant TD and 136 non-TD subjects, we identified association of a single nucleotide polymorphism, rs2445142, (allelic p=2 x 10(-5)) in the HSPG2 (heparan sulfate proteoglycan 2, perlecan) gene with TD. The risk allele was significantly associated with higher expression of HSPG2 in postmortem human prefrontal brain (p<0.01). Administration of daily injection of haloperidol (HDL) for 50 weeks significantly reduced Hspg2 expression in mouse brains (p<0.001). Vacuous chewing movements (VCMs) induced by 7-week injection of haloperidol-reserpine were significantly infrequent in adult Hspg2 hetero-knockout mice compared with wild-type littermates (p<0.001). Treatment by the acetylcholinesterase inhibitor, physostigmine, was significantly effective for reduction of VCMs in wild-type mice but not in Hspg2 hetero-knockout mice. These findings suggest that the HSPG2 gene is involved in neuroleptic-induced TD and higher expression of HSPG2, probably even after antipsychotic treatment, and may be associated with TD susceptibility.

Mechanisms underlying the comorbidity of tobacco use in mental health and addictive disorders

We discuss potential explanations for the high prevalence of tobacco use and tobacco dependence (TD) in people with mental health and addictive (MHA) disorders. The biopsychosocial basis for this comorbidity is presented, integrating evidence from epidemiologic and clinical studies. We also review evidence that suggests a shared vulnerability related to biological, genetic, and environmental factors may be the most parsimonious mechanism to explain the association between TD and MHA disorders. Finally, we review the examples of various MHA disorders that are associated with TD, and suggest avenues for new investigation that could aid in the development of rationale and more effective treatments for tobacco and MHA disorder comorbidities.

Genetic study of BDNF, DRD3, and their interaction in tardive dyskinesia

Tardive dyskinesia (TD) is a neuroleptic-induced movement disorder. Its pathophysiology is unclear. The most consistent genetic findings have shown an association with the Ser9Gly polymorphism of the DRD3 gene. However, only few polymorphisms within DRD3 has been tested, and a comprehensive examination of DRD3 in TD is still lacking. Further, brain-derived neurotrophic factor (BDNF), a neuronal growth and survival peptide, regulates DRD3 expression and may be involved in the neuronal degeneration observed in TD. In the present study, we investigated 15 tag DRD3 polymorphisms and four tag BDNF polymorphisms for association with TD in our sample of Caucasian schizophrenia patients (N=171). While BDNF markers showed no association, a haplotype containing rs3732782, rs905568, and rs7620754 in the 5' region of DRD3 was associated with TD diagnosis (p[10,000 permutations]=0.007). We also found evidence of interaction between BDNF and DRD3 polymorphisms. Further studies are needed to confirm these findings.

Influence of spirituality and religiousness on smoking among patients with schizophrenia or schizo-affective disorder in Switzerland

BACKGROUND

The rates of cigarette smoking among patients with schizophrenia are two to four times the rates observed in the community. Spirituality and religiousness have been shown to be associated with lower smoking rates in the general population.

AIMS

This study assessed the role of religion in cigarette smoking among patients with schizophrenia or schizo-affective disorder.

METHODS

Some 115 stabilized outpatients from Geneva's public psychiatric facilities were included. Interviews were conducted to investigate spiritual and religious beliefs, religious practices and religious coping. Cigarette smoking was assessed through interviews and medical records.

RESULTS

Some 58% of patients were smokers. Two-thirds of the total sample considered spirituality as very important or essential in their every day life. Religiosity was negatively associated with tobacco use: there were more current smokers without religious affiliation than non-smokers (p < 0.05). For non-smokers, the support of their faith community was significantly more important and they reported more frequent group religious practices than smokers ( p < 0.05). This relation persisted after controlling for demographic confounders (gender, age, ethnicity, education, civil status).

CONCLUSION

In patients with schizophrenia, religion and spirituality seem to be related to smoking behaviour. Similar results were previously found in the general population. These results underscore the need for a systematic exploration of religious issues in the care of smokers with schizophrenia.

Acute risperidone treatment did not increase daily cigarette consumption or plasma levels of cotinine and caffeine: a pilot study

Excessive cigarette smoking and caffeine intake are often seen in schizophrenic patients being treated with antipsychotic drugs, particularly typical antipsychotic drugs. Using nicotine and caffeine sometimes influences psychotic symptoms in these patients. Clozapine is the only antipsychotic drug reported to reduce the amount of cigarette smoking, however, still remains controversial of its efficacy. In the present study, we examined the effect of acute risperidone treatment on the amount of cigarette smoking and plasma levels of cotinine and caffeine in schizophrenic patients. Treatment with risperidone for 4 weeks did not increase daily cigarette consumption or plasma levels of cotinine and caffeine. The results suggest that acute risperidone treatment does not promote the intake of nicotine and caffeine at least by 4 weeks in schizophrenic patients.

[Tobacco and schizophrenia: therapeutic aspects]

Although patients with have low motivations to quit smoking, smoking cessation treatment can be effective for these patients. Patients schizophrenia who achieve significant smoking reduction during a treatment intervention can at least maintain that level of reduction at 2 years. Cigarette smoking by patients with frequently goes unaddressed, contributing to excess mortality in this population. Behavioural interventions improve smoking cessation in schizophrenia patients. Nicotine replacement can substantially reduce withdrawal symptoms. Bupropion enhances smoking abstinence rates. Bupropion is well-tolerated and safe for use in schizophrenia patients: bupropion does not worsen clinical symptoms of schizophrenia. Atypical antipsychotics may reduce smoking consumption in schizophrenia patients, in particular clozapine. Atypical antipsychotic medication, in combination with the nicotine transdermal patch, significantly enhance the rate of smoking cessation. Interactions between smoking and antipsychotic medication - Smoking increases the metabolism of the antipsychotic medications by inducing the cytochrome P450 1A2 isoform. Smoking lowers the blood levels of typical or atypical antipsychotic medication, in particular haloperidol, chlorpromazine, olanzapine and clozapine. -Abstinence can increase many psychotropics' blood levels. Accordingly, smoking appears to reduce neuroleptic-induced parkinsonism. In contrast, smoking is a risk factor for tardive dyskinesia, independent of neuroleptic exposure.

Association study of tardive dyskinesia and twelve DRD2 polymorphisms in schizophrenia patients

Tardive dyskinesia (TD) is a side-effect of chronic antipsychotic medication. Abnormalities in dopaminergic activity in the nigrostriatal system have been most often suggested to be involved because the agents which cause TD share in common potent antagonism of dopamine D2 receptors (DRD2), that notably is not balanced by effects such as more potent serotonin (5-HT)2A antagonism. Thus, a number of studies have focused on the association of dopamine system gene polymorphisms and TD. The most consistent findings have been found with the Ser9Gly polymorphism of the DRD3 gene. Although DRD2 has long been hypothesized to be the main target for antipsychotics, only a few polymorphisms in DRD2 have been investigated for their potential involvement in the aetiology of TD. In the present study, we investigated 12 polymorphisms spanning the DRD2 gene and their association with TD in our European Caucasian (n=202) and African-American (n=30) samples. Genotype frequencies for a functional polymorphism, C957T (Duan et al., 2003; Hirvonen et al., 2004), and the adjacent C939T polymorphism were found to be significantly associated with TD (p=0.013 and p=0.022 respectively). DRD2 genotypes were not significantly associated with TD severity as measured by AIMS (Abnormal Involuntary Movement Scale) with the exception of a trend for C939T (p=0.071). Both TD and total AIMS scores were found to be significantly associated with two-marker haplotypes containing C939T and C957T (p=0.021 and p=0.0087 respectively). Preliminary results indicated that C957T was also associated with TD in our African-American sample (p=0.047). Taken together, the present study suggests that DRD2 may be involved in TD in the Caucasian population, although further studies are warranted.

Antipsychotic-induced extrapyramidal symptoms in patients with schizophrenia: associations with dopamine and serotonin receptor and transporter polymorphisms

BACKGROUND

Little is known about the influence of polymorphisms of the dopamine and serotonin system on the risk for extrapyramidal symptoms (EPS) during treatment with antipsychotic drugs.

METHODS

Of 119 subjects with schizophrenia treated with antipsychotics, 63 had current or previous EPS (acute dystonia, parkinsonism, tardive dyskinesia), and 56 had no such symptoms. All subjects were genotyped for a total of eight dopamine and serotonin receptor and transporter polymorphisms: the Taq1A polymorphism of the dopamine D(2) receptor (DRD2) gene, the Msc1 polymorphism of the dopamine D(3) receptor (DRD3) gene, the variable number of tandem repeat (VNTR) polymorphism of the dopamine transporter (DAT1) gene, four polymorphisms (102T/C, His452Tyr, 516 C/T, and Thr25Asn) of the serotonin 5-HT(2A) receptor (5HTR2A) gene, and the 5HTTLPR polymorphism of the serotonin transporter (5HTT) gene.

RESULTS

The frequency of the A1 allele of the DRD2 Taq1A polymorphism was significantly higher in the EPS group than in the control group [16% vs. 7%, P = 0.040; odds ratio (OR) 2.4; 95% confidence interval (CI) 1.1-5.7]. Also, the 9 repeat allele of the DAT1 VNTR polymorphism was significantly more common in the EPS group (42% vs. 28%, P = 0.030; OR 1.9; 95% CI 1.1-3.3). Being a carrier of both DRD2 Taq1A A1 and DAT1 VNTR 9 repeat alleles was also significantly associated with the occurrence of EPS (19% vs. 6%, P = 0.040; OR 4.0; 95% CI 1.05-15.2) No significant differences in allele frequencies were found for the other polymorphisms.

CONCLUSION

Presence of the Taq1A A1 allele of the DRD2 and the 9 repeat allele of the DAT1 VNTR polymorphisms might be risk factors for EPS caused by antipsychotic drugs.

Movement disorders: neurodevelopment and neurobehavioural expression

Braak and co-workers have recently shown that movement disorders such as Parkinson's disease develop progressively over years with early neuronal losses in brainstem regions caudal to the substantia nigra. The relevance of this finding to notions of comorbidity between movement disorders and psychiatric symptoms was recognised at the recent meeting concerning, "Implications of Comorbidity for the Etiology and Treatment of Neuropsychiatric Disorders" held in Oct. 2005 in Mazagon, Spain. The identification of stages in the early development of neurodegenerative disorders appeared to unify multiple, diverse findings. These included: novel therapeutic innovations for Parkinson's disease, Alzheimer's disease and depression in the aged; the neurochemical ontogeny of drug-induced oral dyskinesias; the types of chemical agents abused in neuropsychiatric states; postnatal iron overload effects upon the functional and interactive role of dopaminergic and noradrenergic pathways that contribute to the expression of movement disorders; and the spectrum of motor symptoms expressed in schizophrenia and attention deficit hyperactivity disorder and the eventual treatment of these disorders. A continued focus on a number of neuropsychiatric diseases as progressive disorders may lead to further advances in understanding their etiology and in developing better therapeutics.

Does smoking reduce akathisia? Testing a narrow version of the self-medication hypothesis

BACKGROUND

The self-medication hypothesis proposes that schizophrenia patients smoke to decrease their schizophrenia symptoms or antipsychotic side effects, but they usually start smoking before their illness and heavy smoking is not consistently associated with fewer symptoms or side effects. A narrow version of the self-medication hypothesis, heavy smoking reduces akathisia, is explored.

METHOD

The sample included 250 outpatients with DSM-IV schizophrenia assessed with the Positive and Negative Syndrome Scale (PANSS) and the Barnes Akathisia Scale. Prevalences were 69% (173/250) for smoking, 39% (98/250) for heavy smoking (> or =30 cigarettes/day), 7% (17/250) for akathisia (Barnes Global score>1), 14% (35/250) for a broader akathisia definition (Barnes Global score>0) and 20% for excited symptoms (>1 on the PANSS factor score).

RESULTS

Heavy smoking was not associated with akathisia (41% of patients with akathisia were heavy smokers versus 39% of patients without akathisia; chi2=0.3, df=1, p=0.86), even after correcting for confounding factors and/or using a broader akathisia definition. Heavy smoking was associated with excited schizophrenia symptoms (possibly reflecting agitation). Particularly in patients taking lower doses of typical antipsychotics, excited symptoms, with or without akathisia, were strongly associated with heavy smoking and appear to interact with patients' reports of smoking's calming effect as the main reason for smoking.

CONCLUSION

The self-medication hypothesis does not explain increased smoking and heavy smoking in schizophrenia. Moreover, heavy smoking may be associated with more disturbed brain homeostatic mechanisms. Prospective studies need to explore whether temporary increases in cigarette smoking may be associated with periods of higher agitation, with or without akathisia.

Prevalence of and risk factors for tardive dyskinesia in a Xhosa population in the Eastern Cape of South Africa

OBJECTIVE

Despite prolonged use of antipsychotic drug treatment, the prevalence of tardive dyskinesia (TD) in a Xhosa population has not been evaluated. This study was undertaken to assess the prevalence and identify possible factors, including antioxidant intake and smoking history, which may increase or reduce the risk of TD.

METHOD

One hundred two subjects who had been exposed to typical antipsychotic drugs for at least 6 months and were currently on an antipsychotic were screened for abnormal movements using the Abnormal Involuntary Movement Scale (AIMS) rating scale. Data about current and past antipsychotic therapy, diagnoses, smoking history, and dietary factors were gathered from the patient and from chart view.

RESULT

Twenty-eight and four-tenths percent of subjects met criteria for tardive dyskinesia. Years of treatment and total cumulative antipsychotic dose were significant predictors of TD. Subjects with higher total consumption of foods containing antioxidants had lower rates of TD, but only consumption of onions was significantly associated with reduced prevalence. TD was less prevalent in smokers, but this difference did not reach statistical significance. Age, sex, and psychiatric diagnosis did not predict presence of TD.

CONCLUSION

The result of this study indicate that TD in this population is more prevalent than previously believed within this local clinical context. Prolonged treatment and total antipsychotic drug exposure are important risk factors for TD in this population. Further study of the role of concurrent medications and dietary factors is indicated.

Co-morbidity of smoking in patients with psychiatric and substance use disorders

This article reviews cigarette smoking in patients with psychiatric disorders (PD) and substance use disorders (SUD). Rates of smoking are approximately 23% in the U.S. population but approximately two- to four-fold higher in patients with PD and SUD. Many remaining smokers have had repeated smoking cessation failures, possibly due to the presence of co-morbid PD and SUDs. There is modest, evidence-based support for effective treatment interventions for nicotine addiction in PD and SUD. Further research is needed to increase our understanding of nicotine addiction in PD and SUD and develop more effective treatment interventions.

Addressing tobacco among individuals with a mental illness or an addiction

Tobacco dependence among individuals with a mental illness or an addiction is a tremendous problem that goes largely ignored. Studies of genetics, neuroimaging, and nicotinic receptors support a neurobiological link between tobacco use and alcohol dependence, drug dependence, schizophrenia, depression, attention-deficit hyperactivity disorder (ADHD), and anxiety disorders. This paper summarizes the recent literature on this topic and discusses how treatment for tobacco can no longer be ignored in mental-health and addiction-treatment settings. More research is needed as well as a national organized effort to address tobacco in this large segment of smokers.

Does nicotine affect D2 receptor upregulation? A case-control study

OBJECTIVE

Nicotine has a powerful preventive effect on neuroleptic-induced dopamine D2 receptor upregulation in the rat. The aim of this human positron emission tomography (PET) study was to compare upregulation in a smoker and a non-smoker, both of whom had received haloperidol for the same duration of time.

METHOD

Two subjects who had been treated for 16 years with a constant dose of haloperidol were scanned after temporary haloperidol withdrawal, using [11C]-raclopride.

RESULTS

The non-smoker, who had received a dose of 10 mg/day, showed a D2 upregulation of 98% and developed severe and persistent symptoms of tardive dyskinesia (TD) upon withdrawal. The chronic smoker, who had been treated with 40 mg/day, displayed a D2 upregulation of 71% and did not develop TD.

CONCLUSION

These human observations agree with animal data which showed that nicotine can decrease neuroleptic-induced D2 receptor upregulation. This property of nicotine may play a protective role in movement disorders whose pathophysiology involves D2 receptor hypersensitivity.

The effectiveness of nicotine-patch therapy for smoking cessation in patients with schizophrenia

The purpose of this study was to determine the effectiveness of nicotine-patch therapy for smoking cessation in patients with schizophrenia. This was a longitudinal study and sixty-eight schizophrenic patients were assigned to 8 weeks of a nicotine-patch therapy program or a control group. The generalized estimating equation analysis revealed that there were significant reductions in the subjects' nicotine dependence (Fagerstrom Tolerance Questionnaire), the number of cigarettes per day, and CO levels over an 8-week period of nicotine-patch therapy and 3-month follow-up. The point-prevalence rates of abstinence from smoking were an abstinence of 26.9% at 8 weeks and 26.9% at a 3-month follow-up. At the 3-month follow-up, the rate of continuous smoking abstinence in the nicotine-patch group was 23.1%.

Blockade of mesolimbic dopamine transmission dramatically increases sensitivity to the rewarding effects of nicotine in the ventral tegmental area

Nicotine produces rewarding and aversive motivational effects in humans and other animal species. Here, we report that the mammalian ventral tegmental area (VTA) represents a critical neural substrate for the mediation of both the rewarding and aversive properties of nicotine. We demonstrate that direct infusions of nicotine into the VTA can produce both rewarding and aversive motivational effects. While the rewarding effects of higher doses of nicotine were not attenuated by dopamine (DA) receptor blockade, blockade of mesolimbic DA signalling with either systemic or intra-nucleus accumbens (NAc) neuroleptic pretreatment potentiated the sensitivity to nicotine's rewarding properties over a three-order-of-magnitude dose range. Furthermore, the behavioural effects of lower doses of intra-VTA nicotine were reversed, switching the motivational valence of nicotine from aversive to rewarding. Our results suggest that blockade of mesolimbic DA signalling induced by neuroleptic medications may block selectively the aversive properties of nicotine, thus increasing the vulnerability to nicotine's rewarding and addictive properties by inducing a unique, drug-vulnerable phenotype.

Schizophrenia and memory impairment: evidence for a neurocognitive subtype

Evidence is presented that verbal memory impairment distinguishes a subgroup of patients with schizophrenia who also differ in symptom profile and illness adjustment. On the basis of the California Verbal Learning Test (CVLT), a sample of patients was partitioned into memory-impaired (n=16) and memory-unimpaired groups (n=16). Groups were matched for age, sex, IQ, and anti-psychotic medication. These groups were then compared using the Brief Psychiatric Rating Scale (BPRS) and the Sickness Impact Profile (SIP). Results indicate that memory-impaired schizophrenia patients experience significantly more positive symptoms and a poorer quality of life than their memory-unimpaired counterparts. This finding supports the idea that neurocognitive measures are a valuable way of organizing the heterogeneous disease states of schizophrenia.

Neuroadaptations to chronic exposure to drugs of abuse: relevance to depressive symptomatology seen across psychiatric diagnostic categories

Depressive symptomatology is expressed across a wide spectrum of psychiatric disorders including major depression and schizophrenia. Further, depressive symptomatology is also observed in individuals undergoing withdrawal from chronic exposure to various drugs of abuse including cocaine, amphetamine and nicotine. The negative affective state associated with drug withdrawal is phenomenonologically similar to that observed in depressed and schizophrenia patients suggesting that common underlying pathophysiological deficits may be involved in the depressive symptomatology seen across these different psychiatric disorders. The aim of the present review is to examine clinical and preclinical evidence in support of a common neurobiological substrate mediating the negative affect associated with different psychiatric illnesses. First, clinical and epidemiological data are presented demonstrating the high comorbidity between nicotine and psychostimulant dependence, and depression or schizophrenia. It is hypothesized that drug-use may represent an attempt to self-medicate an underlying negative affective state present in depressed and schizophrenia patients. Second, preclinical findings are presented that demonstrate common neurochemical deficits in drug withdrawal and depression. Taken together, these clinical and preclinical data support the hypothesis that common neurobiological substrates may mediate the depressive state observed across psychiatric diagnostic categories. Therefore, it is proposed that the study of drug-induced depressions in laboratory animals may have heuristic value in identifying the mechanisms underlying the depressive symptomatology associated not only with drug withdrawal but also major depression and schizophrenia.

Concomitant clozapine reduces smoking in patients treated with risperidone

This pilot study examines the smoking behaviors of patients treated with either risperidone alone or in combination with clozapine. Smoking behavior was evaluated using expired carbon monoxide (CO) measurements, the Fagerstrom Test for Nicotine Dependence (FTND), and a semi-structured interview. Our results indicate that patients co-prescribed clozapine with risperidone smoke significantly less than patients treated with risperidone alone (19.1+/-9.3 vs. 37.8+/-19.1 ppm CO, respectively, P=0.03). These data are consistent with previous studies showing that clozapine treatment is associated with significantly reduced smoking behavior relative to other antipsychotic agents.

Smoking in patients receiving psychotropic medications: a pharmacokinetic perspective

Many psychiatric patients smoke, and are believed to be heavier smokers than those without psychiatric disorders. Cigarette smoking is one of the environmental factors that contributes to interindividual variations in response to an administered drug. Polycyclic aromatic hydrocarbons (PAHs) present in cigarette smoke induce hepatic aryl hydrocarbon hydroxylases, thereby increasing metabolic clearance of drugs that are substrates for these enzymes. PAHs have been shown to induce 3 hepatic cytochrome P450 (CYP) isozymes, primarily CYP1A1, 1A2 and 2E1. Drug therapy can also be affected pharmacodynamically by nicotine. The most common effect of smoking on drug disposition in humans is an increase in biotransformation rate, consistent with induction of drug-metabolising enzymes. Induction of hepatic enzymes has been shown to increase the metabolism and to decrease the plasma concentrations of imipramine, clomipramine, fluvoxamine and trazodone. The effect of smoking on the plasma concentrations of amitriptyline and nortriptyline is variable. Amfebutamone (bupropion) does not appear to be affected by cigarette smoking. Smoking is associated with increased clearance of tiotixene, fluphenazine, haloperidol and olanzapine. Plasma concentrations of chlorpromazine and clozapine are reduced by cigarette smoking. Clinically, reduced drowsiness in smokers receiving chlorpromazine, and benzodiazepines, compared with nonsmokers has been reported. Increased clearance of the benzodiazepines alprazolam, lorazepam, oxazepam, diazepam and demethyl-diazepam is found in cigarette smokers, whereas chlordiazepoxide does not appear to be affected by smoking. Carbamazepine appears to be minimally affected by cigarette smoke, perhaps because hepatic enzymes are already stimulated by its own autoinductive properties. Cigarette smoking can affect the pharmacokinetic and pharmacodynamic properties of many psychotropic drugs. Clinicians should consider smoking as an important factor in the disposition of these drugs.

A comparison of smoking behaviours between patients treated with clozapine and depot neuroleptics

The high prevalence of smoking among individuals diagnosed with schizophrenia is well recognized and documented. Many explanations have been put forth to explain this phenomenon including the effects of antipsychotic medication. We sought to determine if there is a difference in smoking behaviour between patients treated with clozapine and depot neuroleptics. This cross-sectional study recruited patients with schizophrenia from the Forensic Psychiatric Institute of British Columbia. Eligibility for the study required that patients be on either clozapine or depot neuroleptic for at least 2 months. The patient's smoking behaviour was evaluated using expired carbon monoxide (CO) measurements, the Fagerstrom Test for Nicotine Dependence (FTND), and a semi-structured interview. Our results showed that patients treated with clozapine had significantly lower expired CO values than patients treated with depot neuroleptics (11.8 +/- 9.2 versus 21.2 +/- 7.1 p.p.m., respectively, P < 0.01). This finding was further supported by the noted trend in which patients receiving clozapine self-reported smoking less than patients treated with depot neuroleptics (13.7 +/- 11.3 versus 26.8 +/- 18.3 cigarettes per day, respectively, P = 0.08). Thus, according to measurements of expired CO levels, patients treated with clozapine smoke less than patients treated with depot neuroleptics.

Antipsychotic medication and smoking prevalence in acutely hospitalized patients with chronic schizophrenia

The atypical antipsychotic, clozapine, has been reported to reduce smoking in schizophrenic patients. We sought to determine whether other atypical antipsychotics would also be associated with a decreased prevalence of smoking in this population. Data were obtained from three groups of chronic, hospitalized, schizophrenic patients, receiving either a typical antipsychotic (n=15), clozapine (n=6), or another atypical antipsychotic (n=18). In addition to smoking prevalence, the groups were compared with regard to demographics (age, education), medication (doses, duration of treatment, side-effects), clinical (diagnosis, duration of illness) and behavioral (Wide-Range Achievement Test, Wechsler Adult Intelligence Scale) variables. Smoking prevalence differed significantly among the three groups (P<0.001). Clozapine was associated with a significantly lower incidence of smoking than either typical drugs (P<0.003) or other atypical antipsychotics (P=0. 042). The groups did not differ on demographic or other medication variables or on any of several behavioral measures. However, a diagnosis of paranoid schizophrenia was also significantly correlated with smoking (P<0.01), but not with medication class. Although the cause is still unknown, these results are consistent with reports that clozapine reduces smoking and provide new data on smoking prevalence associated with other atypical agents.

Smoking and schizophrenia: abnormal nicotinic receptor expression

Biological and genetic evidence suggests a role for the neuronal nicotinic receptors in the neuropathophysiology of schizophrenia. Nicotine normalizes an auditory evoked potential deficit seen in subjects who suffer from the disease. Nicotinic receptors with both high and low affinity for nicotine are decreased in postmortem brain of schizophrenics compared to control subjects. The chromosomal locus of the human alpha-7 gene (15q14) is linked to the gating deficit with a lod of 5.3, and antagonists of the alpha-7 receptor (alpha-bungarotoxin and methyllycaconitine) induce a loss of gating in rodents. We have cloned the human alpha-7 gene and found it to be partially duplicated proximal to the full-length gene. The duplication is expressed in both the brain and in peripheral blood cells of normal subjects, but is missing in some schizophrenic subjects. The results of these studies suggest the presence of abnormal expression and function of the neuronal nicotinic receptor gene family in schizophrenia.

Smoking and Persistent Mental Illness: An Exploratory Study

The rate of smoking is alarmingly high among persons with persistent mental illness and they are no less susceptible to the harmful effects of smoking. Nicotine is a potent, addictive drug which affects neurotransmitters. Smoking can affect psychiatric symptoms as well as blood levels of psychotropic and other medications. Most persons with mental illness are aware of the detrimental health risks of smoking and many are interested in quitting. Poor physical health is associated with efforts to quit. Personal commitment is important to successfully quitting.

Smoking habits, current symptoms, and premorbid characteristics of schizophrenic patients in Nithsdale, Scotland

OBJECTIVE

Previous studies of smoking habits of schizophrenic patients have found rates as high as 88%. The authors report the smoking habits of all known schizophrenic patients within a discrete geographical area and compare them with the smoking habits of a general population sample.

METHOD

All known schizophrenic patients in Nithsdale in South-West Scotland (N = 168) were invited to complete a questionnaire on smoking habits. Also assessed were mental state, drug-related side effects, and premorbid childhood personality and social adjustment.

RESULTS

One hundred thirty-five of the 168 patients returned the questionnaires. The rate of smoking among the patients was 58% (N = 78), compared with 28% in the general population. Sixty-eight percent of the patients who smoked (N = 53) had 25 or more cigarettes per day. The mean age at starting smoking was 17 years in both patients and normal subjects. Ninety percent of the patients who smoked (N = 70) started smoking before the onset of schizophrenia. Patients who smoked were younger than nonsmokers, and more of them were male. They had had more hospitalizations, and more were in contact with psychiatric services. More were receiving intramuscular antipsychotic medication. Smokers had poorer childhood social adjustment. Among the female patients, there was a positive correlation between age at starting smoking and age at onset of schizophrenia.

CONCLUSIONS

The rate of smoking and level of nicotine addiction are greater in schizophrenic patients than in the general population. Smoking may be a marker for the neurodevelopmental form of the illness and may be another environmental risk factor for schizophrenia in vulnerable individuals.

Cigarette smoking is associated with abnormal involuntary movements in the general male population--a study of men born in 1933

Abnormal involuntary movements, i.e., spontaneous and tardive dyskinesias, were studied in a random population sample of 559 men, aged 59 years, who were participating in an epidemiological study focused on cardiovascular health. The research diagnostic criteria for tardive dyskinesia were fulfilled by 8.2% (n = 46), discounting the fact that all had not been exposed to neuroleptics. The mean Abnormal Involuntary Movements Scale score in the dyskinetic group was 5.0 (SD = 1.8), indicating mild to moderate symptoms. Dyskinetic men had higher daily cigarette consumption and higher scores for parkinsonian symptoms. They also had higher frequencies of psychiatric morbidity, exposure to neuroleptics, and alcohol dependence than the men without dyskinesia. In a logistic regression model, exposure to neuroleptics (p < .05) and daily cigarette consumption (p < .0005) were independently associated with dyskinesia. The probability of dyskinesia in a person smoking 20 or more cigarettes per day was 19%, whereas the probability associated with exposure to neuroleptics was 30%.

Smoking, smoking withdrawal and schizophrenia: case reports and a review of the literature

Our efforts to study and understand the complex clinical, behavioral, neurochemical and neuroanatomical manifestations of the schizophrenias are plagued by the heterogeneity of findings, and lack of ability to define subtypes within the syndrome. Theoretically, a behavior associated with schizophrenia among a majority of those affected might provide more broadly applicable information about the illness. Cigarette smoking represents such a behavior. Herein we present an overview of evidence linking cigarette smoking and schizophrenia, and describe three cases suggesting that nicotine withdrawal leads to an exacerbation of schizophrenic symptoms.