Personality traits and smoking in patients with obsessive-compulsive disorder

Global prevalence of smoking among individuals with obsessive-compulsive disorder and symptoms: a systematic review and meta-analysis

Disease from nicotine dependency continues to be a leading cause of preventable death worldwide, and therefore research that elucidates potential correlates of tobacco use may facilitate the advancement of research, clinical practice, and policy in this area to target this public health challenge. One potential tobacco use correlate is obsessive-compulsive disorder (OCD) phenomena. The growing research evidence on the association between tobacco use and OCD phenomena is mixed, making it difficult to synthesize extant findings into meaningful conclusions. Indeed, there has never been a systematic review or meta-analysis of this area of research. To this end, a systematic review was carried out with studies between 1988 and 2021, and from this review, 71 independent estimations (n = 10,475; Females = 51.95%; mean age = 37.29, SD = 13.78) were extracted for meta-analysis. We found that about three in ten participants with OCD are likely to use tobacco, which is higher than the general population. The prevalence was the same among OCD participants at all levels (those with symptomology but no confirmed diagnosis, those surpassing a clinical cutoff for OCD but no confirmed diagnosis, and those with a confirmed OCD diagnosis). The results also indicated considerable variability across study results and a wide confidence interval associated with the tobacco use prevalence rate among those with OCD phenomena. The findings provide support for continued study of this comorbidity, perhaps with longitudinal and experimental designs to test for reciprocal associations between tobacco use and OCD phenomena in the service of targeting nicotine dependence as a substantial global public health concern.

Suicidal Ideation and Obsessive-Compulsive Disorder: Links and Knowledge

Suicidal ideation (SI) is understudied in obsessive-compulsive disorder (OCD). Nonetheless, evidence suggests increased risk for SI in individuals with OCD compared to the general population. Understanding the relationship between SI and OCD involves investigating risk factors associated with SI. Furthering knowledge of links is essential for enhancing outcomes and decreasing experiences of SI through improving treatment interventions. Additionally, increasing awareness of factors that lead SI to suicide attempts (SA) is vital. To best illustrate the current state of knowledge, this scoping review examines risk factors for SI, including symptom profiles or phenotypes, comorbid diagnoses, sociodemographic and lifestyle factors, childhood trauma, and genetic and familial contributions. Important treatment considerations for targeting SI within the context of OCD are detailed with respect to the current evidence for psychotherapy, pharmacology, brain stimulation, and neurosurgery. Gaps in the literature and future directions are identified, broadly with respect to studies examining the treatment of SI within the context of OCD, particular OCD phenotypes, and factors influencing SI in pediatric OCD. Due to the relative novelty of this area of exploration, many unknowns persist regarding onset of SI in OCD, factors contributing to the maintenance of SI in OCD, and relevant treatment protocols. Findings suggest that individuals with previous SI or SA, history of childhood trauma, significant life stress, and psychiatric comorbidities, particularly depression, should be closely monitored and screened for SI.

Cannabis use and related clinical variables in patients with obsessive-compulsive disorder

OBJECTIVE

Limited studies have investigated cannabis use in patients with obsessive-compulsive disorder (OCD), despite its widespread use by patients with psychiatric illnesses. The aim of this study was to assess the frequency, correlates, and clinical impact of cannabis use in an Italian sample of patients with OCD.

METHODS

Seventy consecutive outpatients with OCD were recruited from a tertiary specialized clinic. To assess cannabis-related variables, patients completed a questionnaire developed for the purpose of this study, investigating cannabis use-related habits and the influence of cannabis use on OCD symptoms and treatments. A set of clinician and self-reported questionnaires was administered to measure disease severity. The sample was then divided into three subgroups according to the pattern of cannabis use: "current users" (CUs), "past-users" (PUs), and "non-users" (NUs).

RESULTS

Approximately 42.8% of patients reported lifetime cannabis use and 14.3% reported current use. Approximately 10% of cannabis users reported an improvement in OCD symptoms secondary to cannabis use, while 23.3% reported an exacerbation of anxiety symptoms. CUs showed specific unfavorable clinical variables compared to PUs and NUs: a significant higher rate of lifetime use of tobacco, alcohol, and other substances, and a higher rate of pre-OCD onset comorbidities. Conversely, the three subgroups showed a similar severity of illness.

CONCLUSION

A considerable subgroup of patients with OCD showed a predisposition towards cannabis use and was associated with some specific clinical characteristics, suggesting the need for targeted consideration and interventions in this population.

Efficacy of nicotine administration on obsessions and compulsions in OCD: a systematic review

BACKGROUND

Preliminary studies have tested nicotine as a novel treatment for OCD patients who respond partially/incompletely or not at all to first and second-line treatment strategies, with the former represented by SSRIs or clomipramine, and the latter by switching to another SSRI, or augmentation with atypical antipsychotics, and/or combination with/switching to cognitive-behavioural therapy. Some studies found nicotine-induced reduction of obsessive thoughts and/or compulsive behaviour in OCD patients. We aimed to evaluate the efficacy of nicotine administration in OCD patients.

METHODS

We searched the PubMed, ScienceDirect Scopus, CINHAL, Cochrane, PsycINFO/PsycARTICLES, and EMBASE databases from inception to the present for relevant papers. The 'Preferred Reporting Items for Systematic Review and Meta-Analyses' (PRISMA) standards were used. We included all studies focusing on the effects of nicotine administration on OCD patients' obsessions or compulsions. Studies could be open-label, cross-sectional, randomized controlled trials, case series or case reports.

RESULTS

A total of five studies could be included. Nicotine administration may ameliorate behavioural features and recurrent thoughts of severe, treatment-resistant OCD patients; however, in one study it was not associated with OC symptom improvement or cognitive enhancement across various executive function subdomains.

CONCLUSIONS

Although encouraging, the initial positive response from the use of nicotine in OCD needs testing in large controlled studies. This, however, raises ethical issues related to nicotine administration, due to its addiction potential, which were not addressed in the limited literature we examined. As an alternative, novel treatments with drugs able to mimic only the positive effects of nicotine could be implemented.

Prevalence and correlates of smoking and nicotine dependence: results of a nationwide cross-sectional survey among Singapore residents

BACKGROUND

Since the Singapore Mental Health Study in 2010 which reported a 16.0% prevalence rate for current smokers and 4.5% for nicotine dependence, new anti-smoking strategies have been implemented. The aim of this study was to compare smoking trends from the 2010 study with the second Singapore Mental Health Study in 2016 (SMHS 2016).

METHODS

A survey of 6126 individuals aged 18 years and above randomly selected among Singapore residents was conducted using the same methodology as the 2010 study. The measures used in this analysis were sociodemographic questions, the Composite International Diagnostic Interview which assessed for psychiatric disorders, the Fagerstrom Test for Nicotine Dependence and a list of chronic physical conditions that were prevalent in Singapore. Logistic regression analyses were used to test for associations between smoking/nicotine-dependence and other measures.

RESULTS

In the SMHS 2016, 16.1% were current smokers and 3.3% were nicotine-dependent. As compared with non-smokers, current smokers were more likely to be younger, male gender, of ethnic minority and had lower/vocational education level. Younger age, male gender, lower/vocational education and psychiatric disorders (major depression, bipolar disorder and alcohol use disorders) predicted nicotine dependence. No associations were found between nicotine dependence and any of the chronic conditions.

CONCLUSION

The prevalence of current smokers in the population has plateaued while that of nicotine dependence has decreased from 2010. However, the study did not investigate the use of e-cigarettes. Inequalities in smoking and nicotine dependence continue to pervade the population particularly among those of ethnic minority, lower/vocational education and the mentally ill.

Impulsivity related personality traits and cigarette smoking in adults: A meta-analysis using the UPPS-P model of impulsivity and reward sensitivity

BACKGROUND

Although there is considerable evidence of an association between impulsivity and cigarette smoking, the magnitude of this association varies across studies. Impulsivity comprises several discrete traits that may influence cigarette use in different ways. The present meta-analysis aims to examine the direction and magnitude of relationships between specific impulsivity-related traits, namely lack of premeditation, lack of perseverance, sensation seeking, negative urgency, positive urgency and reward sensitivity and both smoking status and severity of nicotine dependence in adults across studies and to delineate differences in effects across these relationships.

METHODS

Ninety-seven studies were meta-analysed using random-effects models to examine the relationship between impulsivity-related traits and smoking status and severity of nicotine dependence. A number of demographic and methodological variables were also assessed as potential moderators.

RESULTS

Smoking status and severity of nicotine dependence were significantly associated with all impulsivity-related traits except reward sensitivity. Lack of premeditation and positive urgency showed the largest associations with smoking status (r = 0.20, r = 0.24 respectively), while positive urgency showed the largest association with severity of nicotine dependence (r = 0.23). Study design moderated associations between lack of premeditation and lack of perseverance and smoking status, with larger effects found in cross-sectional compared to prospective studies.

CONCLUSIONS

Finding suggest that impulsivity is associated with an increased likelihood of being a smoker and greater nicotine dependence. Specific impulsivity-related traits differentially relate to smoking status and severity of nicotine dependence. Understanding the complexity of impulsivity-related traits in relation to smoking can help to identify potential smokers and could inform cessation treatment.

Attenuation of Compulsive-Like Behavior Through Positive Allosteric Modulation of α4β2 Nicotinic Acetylcholine Receptors in Non-Induced Compulsive-Like Mice

Nicotinic α4β2 receptors are the most abundant subtypes of nicotinic acetylcholine receptors (nAChRs) expressed in brain regions implicated in obsessive compulsive disorder (OCD). These receptors are known to modify normal and addictive behaviors by modulating neuronal excitability. Desformylflustrabromine (dFBr) is a novel, positive allosteric modulator (PAM) of high acetylcholine sensitivity (HS) and low acetylcholine sensitivity (LS) α4β2 nAChRs. The present study tested the hypothesis that positive allosteric modulation of α4β2 receptors by dFBr will attenuate compulsive-like behavior in a non-induced compulsive-like mouse model. Male mice (Mus musculus) selected for compulsive-like nesting behavior (NB; 48 animals; 12 per group) received acute (once) and chronic (every day for 32 days) subcutaneous injection of dFBr at 2, 4 and 6 mg/kg doses. Saline was used as a control (0 mg/kg). Compulsive-like NB was assessed after 1, 2, 3, 4, 5 and 24 h, while compulsive-like marble burying (MB) and anxiety-like open field (OF) behaviors were performed 2 h after dFBr administration. In the acute administration protocol, dFBr dose dependently attenuated NB and MB. Rapid effects (1–2 h after drug administration) of dFBr on MB and NB were observed for the chronic administration which was in congruence with the acute study. Chronic administration also revealed sustained suppression of NB by dFBr following 5 weeks of treatment. In both the acute and chronic regimen dFBr did not modulate OF behaviors. This research demonstrates the novel role of positive allosteric modulation of α4β2 nicotinic receptors by dFBr as a translational potential for OCD.

Cigarette smoking in patients with obsessive compulsive disorder: a report from the International College of Obsessive Compulsive Spectrum Disorders (ICOCS)

Obsessive compulsive disorder (OCD) showed a lower prevalence of cigarette smoking compared to other psychiatric disorders in previous and recent reports. We assessed the prevalence and clinical correlates of the phenomenon in an international sample of 504 OCD patients recruited through the International College of Obsessive Compulsive Spectrum Disorders (ICOCS) network. Cigarette smoking showed a cross-sectional prevalence of 24.4% in the sample, with significant differences across countries. Females were more represented among smoking patients (16% vs 7%; p<.001). Patients with comorbid Tourette's syndrome (p<.05) and tic disorder (p<.05) were also more represented among smoking subjects. Former smokers reported a higher number of suicide attempts (p<.05). We found a lower cross-sectional prevalence of smoking among OCD patients compared to findings from previous studies in patients with other psychiatric disorders but higher compared to previous and more recent OCD studies. Geographic differences were found and smoking was more common in females and comorbid Tourette's syndrome/tic disorder.

An initial investigation of the relationships between hoarding and smoking

Cigarette smokers have increased rates of mood and anxiety-related conditions. Hoarding is another anxiety-related condition that has yet to be examined in relation to smoking behavior. The current investigation sought to examine smoking rates among a sample of individuals with hoarding disorder and individuals with non-hoarding obsessive-compulsive disorder (OCD). Additionally, we examined the relationship between hoarding symptoms and reasons for smoking. Participants in Study 1 consisted of 57 individuals with non-hoarding OCD or hoarding disorder. Participants in Study 2 consisted of 661 adult daily smokers. Results revealed that a significantly greater proportion of individuals diagnosed with hoarding were current smokers compared to the non-hoarding OCD group. Additionally, hoarding severity was associated with negative affect reduction expectancies. These results provide important information regarding smoking behaviors within hoarding disorder. Given the poor treatment outcomes and negative health risks associated with hoarding, this information could inform future research and treatment programs.

Cigarette smoking in obsessive-compulsive disorder and unaffected parents of OCD patients

BACKGROUND

Cigarette smoking is more prevalent among individuals with psychiatric disorders than the general population. Obsessive-compulsive disorder (OCD) may be an intriguing exception, although no recent study has investigated this hypothesis in OCD patients. Moreover, it is unknown whether reduced smoking rates are present in unaffected first-degree relatives of OCD patients.

METHODS

We assessed smoking prevalence in adults with OCD and unaffected parents of youth with OCD (PYOCD). To this end, 113 adults with OCD completed online questionnaires assessing symptom severity and smoking status. Smoking status was obtained from an independent sample of 210 PYOCD assessed for psychiatric diagnoses.

RESULTS

Smoking prevalence rates in adults with OCD (13.3%; n=15) and PYOCD (9.5%; n=20) samples were significantly lower than those found in representative samples of the general population (19-24%, all P<.001) and Axis I disorders (36-64%; all P<.001). There were no smokers in the adult OCD subset without clinically significant depressive symptoms (n=54).

CONCLUSION

Low prevalence of smoking in OCD may be familial and unique among psychiatric disorders, and might represent a possible state-independent OCD marker. Hypotheses concerning the uncharacteristically low prevalence rates are discussed with relation to OCD phenomenology and pathophysiology.

Cigarette smoking, nicotine dependence and anxiety disorders: a systematic review of population-based, epidemiological studies

BACKGROUND

Multiple studies have demonstrated that rates of smoking and nicotine dependence are increased in individuals with anxiety disorders. However, significant variability exists in the epidemiological literature exploring this relationship, including study design (cross-sectional versus prospective), the population assessed (random sample versus clinical population) and diagnostic instrument utilized.

METHODS

We undertook a systematic review of population-based observational studies that utilized recognized structured clinical diagnostic criteria (Diagnostic and Statistical Manual of Mental Disorders (DSM) or International Classification of Diseases (ICD)) for anxiety disorder diagnosis to investigate the relationship between cigarette smoking, nicotine dependence and anxiety disorders.

RESULTS

In total, 47 studies met the predefined inclusion criteria, with 12 studies providing prospective information and 5 studies providing quasiprospective information. The available evidence suggests that some baseline anxiety disorders are a risk factor for initiation of smoking and nicotine dependence, although the evidence is heterogeneous and many studies did not control for the effect of comorbid substance use disorders. The identified evidence however appeared to more consistently support cigarette smoking and nicotine dependence as being a risk factor for development of some anxiety disorders (for example, panic disorder, generalized anxiety disorder), although these findings were not replicated in all studies. A number of inconsistencies in the literature were identified.

CONCLUSIONS

Although many studies have demonstrated increased rates of smoking and nicotine dependence in individuals with anxiety disorders, there is a limited and heterogeneous literature that has prospectively examined this relationship in population studies using validated diagnostic criteria. The most consistent evidence supports smoking and nicotine dependence as increasing the risk of panic disorder and generalized anxiety disorder. The literature assessing anxiety disorders increasing smoking and nicotine dependence is inconsistent. Potential issues with the current literature are discussed and directions for future research are suggested.

Temperament and character in subjects with obsessive-compulsive disorder

BACKGROUND

The aims of this study were to evaluate the differences between personality traits of patients with obsessive-compulsive disorder (OCD) and normal controls using the Temperament and Character Inventory (TCI) and to examine the relationship of personality traits and the severity of obsessive-compulsive (OC) symptoms. We also aimed to examine the influence a particular personality trait might have on the 5 factor-analyzed symptom dimension scores of OCD.

METHOD

We recruited 130 patients with OCD and 185 age- and sex-matched normal controls. All subjects completed the TCI. Patients with OCD were assessed with the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), the Hamilton Depression Rating Scale, and the factor-analyzed symptom dimension scores from the Y-BOCS checklist.

RESULTS

Patients with OCD had higher harm avoidance scores and lower self-directedness (SD), reward dependence (RD), and cooperativeness (C) scores than the controls. Lower SD scores and lower C scores were associated with OC symptom severity measured by the Y-BOCS after adjusting for age and depression severity. Hoarding dimension of OC symptoms was associated with lower SD scores and higher persistence (P) scores after adjusting for age, OC symptom severity, and depression severity.

CONCLUSIONS

There were significant differences in TCI subscales between patients with OCD and controls. Particular personality traits may have an influence on the severity and the dimensions of OC symptoms.

Diretrizes para cessação do tabagismo - 2008

Estas diretrizes constituem uma ferramenta atualizada e abrangente para auxiliar o profissional de saúde na abordagem do tabagista, recomendando atitudes baseadas em evidências clínicas como a melhor forma de conduzir cada caso. De forma reduzida e mais objetiva possível, o texto final foi agrupado em dois grandes itens: Avaliação e Tratamento. Os dois itens apresentam comentários e níveis de recomendação das referências utilizadas, bem como algumas propostas de abordagem, como por exemplo, redução de danos, em situações específicas ainda pouco exploradas, como recaídas, tabagismo passivo, tabagismo na categoria médica e uso de tabaco em ambientes específicos.

Características psicológicas associadas ao comportamento de fumar tabaco

Este artigo apresenta uma revisão da literatura sobre a psicologia do tabagismo, destacando características de personalidade do fumante como um dos obstáculos à cessação do tabagismo. Descreve-se a relação entre tabagismo e personalidade e, a seguir, a relação do tabagismo com os principais transtornos psiquiátricos. Estudos revelam que os fumantes tendem a ser mais extrovertidos, ansiosos, tensos, impulsivos e com mais traços de neuroticismo e psicoticismo, em comparação a ex-fumantes e não fumantes. A literatura revela, ainda, forte associação entre tabagismo e transtornos mentais, como esquizofrenia e depressão, entre outros. A compreensão dos fatores de natureza psicológica associados ao consumo e à dependência pode contribuir para a elaboração e aperfeiçoamento de estratégias terapêuticas para o tratamento da dependência e/ou programas de cunho educativo/preventivo.

Tobacco smoking in Egyptian schizophrenia patients with and without obsessive-compulsive symptoms

BACKGROUND

Nicotine dependence is common in schizophrenia patients but rare in patients with obsessive-compulsive disorder. Little is known, however, about smoking in schizophrenia patients with obsessive-compulsive symptoms (OCS) especially in a developing country, such as Egypt, that has the highest rate of tobacco consumption in the Middle East and North Africa.

OBJECTIVES

To test a hypothesis that nicotine dependence in schizophrenia patients with-OCS is lower than in those without-OCS.

RESULTS

Out of 87 consecutive schizophrenia patients attending a psychiatric out-patients clinic in Egypt, 34 patients (39%) had significant OCS, and a smoking rate (85.3%) not significantly lower than that of patients without-OCS (90.6%). Patients were reclassified by their Fagerström's scores into 3 groups of nicotine dependence: mild (37 patients), high (21 patients) and very high (29 patients). There were no differences between these groups in terms of YBOCS scores (F=0.324; p=0.724). When comparing PANSS scores of patients, with and without-OCS, those of the former group were higher on the positive symptoms (mean=24.2 versus 20.8; p=0.002), and anxiety/depression (mean=10.8 versus 10.1; p=0.03) but lower on the negative symptoms (mean=15.0 versus 19.4; p=0.000), disorganized thoughts (mean=14.5 versus 17.5; p=0.002), and uncontrolled hostility/excitement) (mean=7.5 versus 9.5; p=0.002). However, there was no significant between-group difference in the total PANSS scores.

CONCLUSIONS

The high and equal rates of smoking in patients with-, and without-OCS, and the lack of difference between YBOCS scores of mild, high and very high nicotine dependence groups undermined our initial hypothesis that nicotine dependence in schizophrenia patients with-OCS is lower than in those without them. Nevertheless, the finding of a distinctive PANSS scores, may support a suggestion that OCS in schizophrenia represent a distinct subtype or dimension.

Relations between Obsessive-Compulsive Disorder and personality: beyond Axis I-Axis II comorbidity

Most research on relations between Obsessive-Compulsive Disorder (OCD) and personality addresses only comorbidity rates between OCD and Obsessive-Compulsive Personality Disorder (OCPD). We first investigated empirical OCD-OCPD relations, but then also examined patterns of dimensional traits in OCD patients versus students and general outpatients. Results did not support a specific OCD-OCPD relation and the implications of this conclusion are discussed. Regarding traits, OCD patients shared with other patients elevated negative affectivity and lower positive affectivity. Differences on several lower order dimensions, including lower scores on manipulativeness, mistrust, and disinhibition distinguished the personality profile of OCD patients from others. Also noteworthy was a pattern of very low self-image for OCD patients, as suggested by the combination of low self-esteem and low entitlement scores. Overall, OCD patients showed a more specific pattern of personality pathology than did general outpatients, who were elevated more generally across personality disorders and negative affectivity scales.

Differences between smokers and nonsmokers with anxiety disorders

Epidemiological data suggest that early smoking increases the risk for emergence of certain anxiety disorders (e.g., panic disorder, generalized anxiety disorder (GAD)), and that presence of certain anxiety disorders (e.g., social anxiety) increases the risk for later development of nicotine dependence. Although some studies report a high prevalence of smoking among anxiety disorders, the extent to which smokers with anxiety disorders differ from their nonsmoking counterparts remains uncertain. Differences between smokers and nonsmokers with anxiety disorders (N=527) were examined with respect to multiple measures of theoretical and clinical interest. Compared to nonsmokers, smokers with anxiety disorders reported greater anxiety sensitivity, anxiety symptoms, agoraphobic avoidance, depressed mood, negative affect, stress and life interference; however, these differences were largely accounted for by panic disorder. No differences were found between smokers and nonsmokers regarding social anxiety, worry, obsessive-compulsive symptoms or positive affect. Differential patterns were observed when evaluating constructs within anxiety disorder diagnoses.

Severity of obsessive-compulsive symptoms is related to self-directedness character trait in obsessive-compulsive disorder

OBJECTIVE

The present study examined the psychobiological Temperament and Character model of personality on obsessive-compulsive disorder (OCD) patients, as well as the relation of temperament and/or character dimensions on the severity of obsessive-compulsive symptoms.

METHODS

Fifty-four subjects diagnosed with OCD, were assessed with the Temperament and Character Inventory, the Yale-Brown Obsessive-Compulsive scale and the Hamilton Rating Scales for depression and anxiety.

RESULTS

Compared with controls, OCD subjects displayed increased harm avoidance and lower self-directedness and cooperativeness. Low self-directedness and high Hamilton depression scores were associated with increased severity of obsessive-compulsive symptoms.

CONCLUSION

The Temperament and Character profile of OCD patients characterized in the present study was in agreement with previous reports using the same personality model and can be linked to some of their behavioral features. Furthermore, our data provides support of the influence that some personality traits may have on the severity of OCD symptoms.

Smoking behaviors across anxiety disorders

The purpose of this study was to test the theory put forth by Zvolensky et al. [Clin. Psychol. Sci. Pract. 10 (2003) 29] that smoking is specifically associated with panic disorder (PD) and not more generally associated with other anxiety disorders. Smoking behaviors were examined across three anxiety disorders: panic disorder with or without agoraphobia, social phobia (SP), and obsessive-compulsive disorder (OCD). A greater proportion of the PD group (40.4%) reported smoking compared to the SP (20%) and OCD (22.4%) groups. Those in the PD group were also more likely than those in the other groups to report being a heavy smoker (greater than 10 cigarettes daily). No significant interaction between diagnosis and smoking status was found for any of the symptom measures. However, participants who smoked had significantly higher scores than nonsmokers on a number of scales, including measures of depression, general anxiety, and distress. Differences in anxiety sensitivity between smokers and nonsmokers approached significance. These findings provide support for Zvolensky et al.'s [Clin. Psychol. Sci. Pract. 10 (2003) 29] theoretical conceptualization and suggest a specific link between smoking and panic disorder. Further investigation is warranted to determine the causal direction of this association.

Low prevalence of smoking in patients with autism spectrum disorders

Psychiatric patients are significantly more often smokers than the general population, the only known exception being obsessive-compulsive disorder (OCD) and catatonic schizophrenia. We have investigated nicotine use in subjects with autism spectrum disorders (ASD). Ninety-five subjects (25 females and 70 males) consecutively diagnosed with any ASD and of normal intelligence were included in the study. Only 12.6% were smokers, compared with 19% in the general population and 47% in a control group of 161 outpatients diagnosed with schizophrenia or a schizophreniform disorder. The results suggest that smoking is rare among subjects with ASD, while the opposite was shown for schizophrenia. If replicated, this finding could suggest biological differences between non-catatonic schizophrenia and ASD, and support the theory of a biological link between ASD and a subtype of OCD, and between ASD and catatonic schizophrenia.