[Why do schizophrenic patients smoke?].
ABSTRACT Patients suffering from schizophrenia are known to show an increased prevalence of nicotine addiction. The aim of this paper is to elucidate the relationship between schizophrenia and (chronic) use of nicotine. Nicotine seems to improve cognitive functions critically affected in schizophrenia, in particular sustained attention, focused attention, working memory, short-term memory, and recognition memory. Furthermore, several studies using evoked potentials (P50 paradigm) and prepulse inhibition of the acoustic startle reflex suggest that deficient preattentive information processing, a core feature of schizophrenia illness, is improved following treatment with nicotine. Smoking can also improve extrapyramidal secondary effects of antipsychotic medication and it induces cytochrome P4501A2, an enzyme system involved in the metabolism of several antipsychotics. There is substantial evidence that nicotine could be used by patients with schizophrenia as a "self-medication" to improve deficits in attention, cognition, and information processing and to reduce side effects of antipsychotic medication. Possible pharmacotherapeutic approaches for the regulation of abnormal neurotransmission at nicotinic acetylcholine receptors are discussed.
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ABSTRACT: Individuals are different 'chronotypes' with early 'larks' and late 'owls' forming the limits of a normal distribution in the population. We recently described that late chronotypes who suffer from a conflict between internal and external time ('social jetlag') suffer from more mental distress and are more likely to smoke than early chronotypes (Wittmann, Dinich, Merrow, and Roenneberg, 2006 . Social jetlag: mis-alignment of biological and social time. Chronobiology International, 23:497-509.). We performed a detailed analysis of the same database collected in 2002 comprising 134 daily smokers and 366 nonsmokers, scrutinizing the relationships between chronotype, smoking, and alcohol consumption as well as psychological well-being using a multiple mediation analysis. On average, smokers tend to be later chronotypes, report more sleep-associated psychosomatic symptoms, are more depressed, less balanced, and less vigilant. The mediation analysis suggests that only those late chronotypes who smoke and those who drink more suffer from increased psychological distress. We suggest that 'chronotype' is introduced as an additional factor in substance use, that is, when considering motives for smoking and drinking.Substance Use & Misuse 01/2010; 45(1-2):15-30. · 1.11 Impact Factor
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ABSTRACT: People with schizophrenia suffer from a variety of symptoms that can be categorized as positive, negative and cognitive symptoms. Cognitive symptoms are not properly treated with antipsychotic medication and are the major cause of disability associated with the disorder. People with schizophrenia smoke more frequently and heavily than the general population. This observation in view of the well established role of nicotinic, cholinergic neurotransmission in cognition led to the hypothesis that people with schizophrenia may use nicotine as a self-medication to ameliorate cognitive symptoms associated with their disease. Furthermore genetic and post-mortem studies point to additional links between nicotinic cholinergic neurotransmission and schizophrenia. This article provides an insight in the possible relationship between schizophrenia and smoking behavior. We focus on the effects of nicotine on individual neurons as well as on neuronal networks. With respect to single neurons the immediate electrophysiological consequences of nicotinic stimulation and the more "metabotropic" effects related to intracellular signal transduction cascades that may lead to plastic changes in the neuron are discussed. With respect to the network level, three systems are discussed: cognition, reward and stress response. The effects of nicotine on cognition may be most pertinent to the problem of schizophrenia, but schizophrenics may also smoke to regulate mood and reduce stress. A better understanding of the molecular and cellular effects of nicotine and how they are related to the pathophysiology and symptomatology of schizophrenia may help to identify new targets for the pharmacotherapy of schizophrenia and of nicotine addiction in schizophrenia.Pharmacopsychiatry 09/2008; 41 Suppl 1:S51-9. · 2.11 Impact Factor
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ABSTRACT: BACKGROUND: Alcohol and substance use disorders (ASUD) are considered to be among the most frequent comorbidities in schizophrenic and affective psychoses and have a significant negative influence on their course and prognosis. In the present study patients with diagnosis from the ICD-10 category F2 or F3 were examined regarding a substance use disorder in a multicentre cross-section evaluation at nine psychiatric hospitals in Baden-Württemberg. The aim of this study is to discuss the current research on substance use disorders and psychosis comorbidity regarding the theoretical models by means of collected data. METHODS: The examination of 50 consecutive admissions per centre is based on a shortened version of the European Severity Index (Europ ASI). An initial urine drug screening was carried out with all patients after admission. Statistical assessment was based on percentage distributions, mean values, standard deviations and suitable correlation analysis. RESULTS: The representative sample included 448 patients. A proportion of 169 patients (37.7%) had a dual diagnosis F2 and F1 and a proportion of 144 patients (32.1%) had a dual diagnosis F3 and F1; 64 patients (14.3%) had an F2 diagnosis and 71 patients (15.8%) had an F3 diagnosis without ASUD. Apart from lifetime use of alcohol (n = 268) and tobacco (n = 325) hypnotics/tranquilizers (n = 214), cannabis (n = 156), opioids (n = 71), stimulants (n = 96) and hallucinogens (n = 36) were consumed. The most frequent combination and long-term intake consisted of tobacco, alcohol, hypnotics/tranquilizer, cannabis and psychostimulants especially in men with schizophrenic disorders. Regarding motivation before first substance use general psychological adjustment disorders (51%), peer impact (42%) and unspecific affective symptoms were predominant. CONCLUSIONS: Altogether the present study clearly demonstrates that patients suffering from schizophrenia, affective disorders and ASUD have significantly higher rates of more severe substance use disorders in their psychosocial environment and more suicidal behaviour than patients without substance misuse. The high rate in the cross-sectional prevalence of tobacco, alcohol, cannabis and psychostimulant use calls for more effective drug prevention.Der Nervenarzt 04/2012; · 0.80 Impact Factor