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E Jönsson

Publications and source records attributed to E Jönsson.

At least 19 recordsLinked to original sources

Not 15 but 50% of smokers develop COPD?--Report from the Obstructive Lung Disease in Northern Sweden Studies.

BACKGROUND: The prevalence of chronic obstructive pulmonary disease (COPD) according to guidelines of today seems considerably higher than has been reported also in recent literature. AIM: To estimate the prevalence of COPD as defined by British Thoracic Society (BTS) criteria and the recent global initiative for chronic obstructive lung disease (GOLD) criteria. Further aims were to assess the proportion of underdiagnosis and of symptoms in subjects with COPD, and to study risk factors for COPD. METHODS: In 1996, 5892 of the Obstructive Lung Disease in Northern Sweden (OLIN) Study's first cohort could be traced to a third follow-up survey, and 5189 completed responses (88%) were received corresponding to 79% of the original cohort from December 1985. Of the responders, a random sample of 1500 subjects were invited to a structured interview and a lung function test, and 1237 of the invited completed a lung function test with acceptable quality. RESULTS: In ages >45 years, the prevalence of COPD according to the BTS guidelines was 8%, while it was 14% according to the GOLD criteria. The absolutely dominating risk factors were increasing age and smoking, and approximately a half of elderly smokers fulfilled the criteria for COPD according to both the BTS and the GOLD criteria. Family history of obstructive airway disease was also a risk factor, while gender was not. Of those fulfilling the BTS criteria for COPD, 94% were symptomatics, 69% had chronic productive cough, but only 31% had prior to the study been diagnosed as having either chronic bronchitis, emphysema, or COPD. The corresponding figures for COPD according GOLD were 88, 51, and 18%. CONCLUSIONS: In ages >45 years, the prevalence of COPD according to the BTS guidelines was 8%, and it was 14% according to the GOLD criteria. Fifty percent of elderly smokers had developed COPD. The large majority of subjects having COPD were symptomatic, while the proportion of those diagnosed as having COPD or similar diagnoses was small.

Aged↗

Underdiagnosis of chronic obstructive pulmonary disease in Northern Sweden.

OBJECTIVE: To assess underdiagnosis of chronic obstructive pulmonary disease. MATERIAL AND METHODS: Two cross-sectional studies of respiratory symptoms and diseases in two population samples of the same age living in the same areas in northern Sweden were performed 6 years apart. In 1986, 5698 (86%) out of 6610 subjects aged 35-36, 50-51 and 65-66 years responded to a postal questionnaire. In 1992 an identical study was performed, and 5617 subjects (87%) out of 6434 responded. Lung function measurements were performed in stratified samples. RESULTS: Of the subjects diagnosed with chronic bronchitis only 25% in 1986 and 23% in 1992 had been diagnosed prior to the study as having chronic bronchitis, emphysema or chronic obstructive pulmonary disease (COPD). Chronic airflow limitation (CAL), used as a surrogate variable for COPD and defined as FEV1/VC <70% and FEV1 <80% of predicted value, was found in 171 subjects in 1986-1987 (12% of the examined subjects), and 166 subjects in 1993-1994 (11%). In 1986-1987, 26% of the subjects with CAL had been diagnosed as having chronic bronchitis or emphysema prior to the survey, while a diagnosis of either asthma, chronic bronchitis or emphysema, or use of asthma medicines, was found in 58%. The corresponding figures in 1993-1994 were 31% and 63%, respectively. The great majority of the subjects with CAL had recurrent wheeze, dyspnoea and chronic productive cough. CONCLUSION: Approximately 60% of the subjects with chronic airflow limitation had been diagnosed prior to the survey as having asthma, chronic bronchitis or emphysema, or were using asthma medicines. The results were similar in 1986-1987 and 1993-1994.

Adult↗

Does non-responder bias have a significant effect on the results in a postal questionnaire study?

BACKGROUND AND AIM: In epidemiological questionnaire studies results can be influenced by non-responder bias. However, in respiratory epidemiology this has been analysed in very few recently published papers. The aim of our paper is to assess if the results found in our previous postal questionnaire study in an adult population in Northern Finland were biased by non-response. METHODS: A random sample of 385 persons from the 1,284 non-responders in a previous postal questionnaire study was examined. The same questionnaire as in the original study was again mailed to these persons, and those still not answering were contacted by phone. RESULTS: Totally 183 complete answers (48%) were collected. Lack of interest (56%) and forgetting to mail the response letter (22%) were the most common reasons to non-response. Typical non-responders were young men and current smokers who less frequently reported respiratory symptoms in exercise and asthma than the responders in the original study. Answers collected by phone gave for some questions higher prevalence rates than postal answers. CONCLUSION: Firstly, in this population the response rate (83.6%) in the original study was high enough to provide reliable results for respiratory symptoms and diseases, only the prevalence of current smoking was biased by non-response. Secondly, the methods used for collecting responses in a non-response study may influence the results.

Adult↗

Incidence of physician-diagnosed asthma in adults--a real incidence or a result of increased awareness? Report from The Obstructive Lung Disease in Northern Sweden Studies.

Only limited data are available about the incidence of asthma based on longitudinal prospective studies. Further, the results from different studies on incidence vary considerably depending on the age composition of the cohorts under study, the used methods and the criteria for disease. Also among adults high incidence rates have been reported during recent years. The aim of this study was to examine to what extent the incidence of physician-diagnosed asthma could be explained by a real incidence of the disease, and to what extend by an increased diagnostic activity or altered diagnostic praxis. Another aim was to study risk factors for asthma based on incident cases. Three cross-sectional surveys have been performed in the same population sample living in the northern-most province of Sweden, Norrbotten. The first survey was performed in 1986, and 5698 subjects, 86% of those invited, responded to a postal questionnaire. Of these, 4754 subjects (83%) participated at the third survey in 1996. After exclusion of all subjects who had reported that they had asthma in 1986, or had been classified as having asthma in 1986, 68 men and 98 women (P=0.02) reported in 1996 that they had been diagnosed as having asthma by a physician. Thus, the cumulative incidence for the 10-year period was 3.2% among men and 4.5% among women. After correction for subjects who already in 1986 had reported symptoms common in asthma, or had been classified as having chronic bronchitis, 97 subjects with incident asthma remained, which corresponded to an annual incidence rate among men of 1.7 and among women of 2.9/1000 persons year(-1) (P=0.1). Clinical examinations confirmed asthma in a large majority of these 97 subjects. Significant risk factors were family history of asthma, both ex- and current smoking, and female sex. The socio-economic groups manual workers and assistant non-manual employees were associated with incident asthma, although not significantly. The increasing prevalence of asthma among adults during recent 10-20 years may to a considerable extent be explained by an increased diagnostic activity or altered diagnostic praxis. Use of different methods when measuring incidence may in part explain the extremely diverging incidence rates of asthma found in different studies.

Aged↗

Asthma, chronic bronchitis and respiratory symptoms among adults in Estonia according to a postal questionnaire.

Epidemiological studies indicate a lower prevalence of asthma in Eastern than Western Europe. This study of the prevalence of asthma, chronic bronchitis, and respiratory symptoms was performed in three different regions of Estonia, a state incorporated in the Soviet Union until 1991. A postal questionnaire was sent to a random sample of 24,307 of the population aged 15-64 years. The response rate was 77.6%. The prevalence of physician-diagnosed asthma was 2.0% or considerably lower than in Northern and Western European countries. The prevalence of wheezing last 12 months, 21.7%, recurrent wheeze, 13.3%, and attacks of shortness of breath, 12.5%, were similar or even higher compared with prevalence rates found in the Nordic countries. The prevalence of physician-diagnosed chronic bronchitis was 10.7%, and was higher among women than in men, although the proportion of current smokers among men, 57%, was considerably greater than in women, 28%. A possible explanation to the high prevalence of respiratory symptoms also among non-smoking women may be exposure to environmental tobacco smoke in small, crowded Estonian homes. Diagnostic criteria based on the Soviet-time definitions is discussed as a possible explanation to the low prevalence of physician-diagnosed asthma and high prevalence of chronic bronchitis in Estonia compared with other Northern European countries.

Adolescent↗

Smoking, respiratory symptoms, and diseases : a comparative study between northern Sweden and northern Finland: report from the FinEsS study.

STUDY OBJECTIVES: The influences of different smoking categories on the prevalence of respiratory symptoms, asthma, and chronic bronchitis have been examined in the most northern province of Sweden, Norrbotten, and in Lapland, Finland. The two areas have similar geographic and demographic conditions. METHODS AND STUDY POPULATION: The study is a part of the FinEsS studies, which are epidemiologic respiratory surveys in progress in Sweden, Finland, and Estonia. A random sample of 20- to 69-years-olds were invited to answer a postal questionnaire about respiratory symptoms, smoking habits, and occupation. In Norrbotten, 8,333 subjects were invited and 7,104 responded (85%). In Lapland, 8,005 were invited and 6,633 responded (83%). RESULTS: The participation by age and sex was similar in both countries. The prevalence of smokers in Lapland was 32% vs 26% in Norrbotten. Significantly more women than men in Norrbotten were smokers, while the opposite was true for Lapland. Sputum production was the most prevalent symptom in both areas, 25% in Lapland vs 19% in Norrbotten. The prevalence of chronic productive cough was 11% in Lapland and 7% in Norrbotten. Bronchitic symptoms were more prevalent in Lapland among both smokers and nonsmokers. A positive family history of chronic obstructive airway disease together with increased number of consumed cigarettes showed an additive effect for both chronic productive cough and wheezing. The odds ratio (OR) for wheezing during the last 12 months was 3.8 for subjects without a family history of obstructive airway disease who consumed > 14 cigarettes per day compared with nonsmokers, but if the subjects had a family history of obstructive airway disease, the risk for wheezing increased to OR 8.4. CONCLUSION: Bronchitic symptoms were more common in Finland. The difference remained also after correction for demographic variables including smoking habits, age and socioeconomic group, and family history of obstructive airway disease. Identical methods, sample composition, and the high participation rate contribute to the validity of the results. Air pollution, including environmental tobacco smoke, may contribute to the difference. To explain the difference, further analysis and investigations of social and environmental factors as well as genetic factors are needed.

Adult↗

Incidence and remission of asthma in schoolchildren: report from the obstructive lung disease in northern Sweden studies.

OBJECTIVE: An increasing prevalence of asthma has been reported worldwide as well as in Sweden. In 1996, the prevalence of asthma and type 1 allergy was investigated in a cohort of 3525 children 7 and 8 years old in 3 areas of northern Sweden. The aim of the present study was to estimate the incidence of asthma and to identify risk factors for incident cases over 1 year. METHODS: The study started with a parental questionnaire, the International Study of Asthma and Allergies in Childhood questionnaire with additional questions, a skin prick test, and a validation study. The cohort was followed up after 1 year with the same questions. The response rate to the questionnaire was 97% in 1996, and 3339 children (97%) participated both in 1996 and 1997. RESULTS: The incidence of physician-diagnosed asthma was 0.9/100/year; of wheezing, 3.8/100/year; and of new frequent or daily users of asthma medicines, 1.1/100/year. There was no difference by sex. The risk factor pattern based on incident cases of asthma was different from that based on prevalent cases. Significant risk factors for incident asthma were a positive skin test (odds ratio [OR]: 9.3; 95% confidence interval [CI]: 3.8-22.7); low birth weight (OR: 7.4; 95% CI: 2.2-24.5); and family history of asthma (OR: 2.6; 95% CI: 1.1-6.3). Having or having had pets at home was associated with a decreased risk for asthma and wheezing based on prevalent cases, although it was associated with an increased risk for incidence of wheezing (OR: 2.9; 95% CI: 1.3-6.2). Remission of asthma, which was reported by 10% of the children with current asthma during 1 year, was associated with a negative skin test. CONCLUSION: The incidence of asthma at the age of 8 years was high, but remission was also common. Important risk factors for the development of asthma at this age were type 1 allergy, low birth weight, and family history of asthma. Furthermore, the results suggest that in a region where sensitivity to domestic animals is a strong risk factor for asthma, the presence of pets in the home may have different effects in early childhood compared with later in childhood.

Asthma↗

A 39-year followup of the Genain quadruplets.

The Genains, a unique group of monozygotic female quadruplets, all developed a schizophrenic disorder by age 24. They have been studied since the 1950s, because of the rarity of this occurrence (estimated to be one in 1.5 billion) and because their illnesses varied in severity. The identical inheritance would tend to rule out genetic differences as the cause of the neuropsychological differences; however, we cannot disentangle the effects of early brain injury and harsh punitive treatment as factors accounting for the differences in the severity of their disorders. We conducted neuropsychological examinations of the Genains at age 66, compared their test profiles, and contrasted certain test scores at 66 with those at ages 27 and 51. Test results indicate generally stable (or even improved) performance over time and support the notion that cognitive decline is not a degenerative process in schizophrenia. The Genains remind us of the exquisite interaction among variables that must be understood before additional, satisfactory progress can be made in preventing the development and predicting the course of schizophrenia.

Adult↗

Increasing prevalence of asthma but not of chronic bronchitis in Finland? Report from the FinEsS-Helsinki Study.

To assess the prevalence of asthma, chronic bronchitis and respiratory symptoms, and to calculate risk factors for them, we performed a postal survey in Helsinki, the capital of Finland. During the spring of 1996, questionnaires were mailed to a random sample of 8000 individuals aged 20-69. The total response rate was 76%, with 6062 complete answers. The prevalence of having ever had asthma was 7.2%, physician-diagnosed asthma was 6.6% and physician-diagnosed chronic bronchitis was 3.7%. Asthma was significantly more common among women than men, but no gender differences existed in prevalence of chronic bronchitis. The most common respiratory symptom was sputum production when coughing, reported by 27%. During the previous 12 months, wheezing had occurred in 20% and attacks of shortness of breath in 13% of subjects. Generally, the prevalence of different respiratory symptoms were significantly higher among smokers. The most important risk factor for asthma was a family history of asthma (Odds ratio:OR 3.3). Multivariate analysis revealed that being a member of the socioeconomic group, manual workers, was associated with a significantly increased risk for chronic productive cough (OR 1.7), and for wheezing during the previous 12 months (OR 1.7). Manual workers of both genders had the highest prevalence of asthma, chronic productive cough and wheezing during the previous 12 months. The prevalence of asthma in Helsinki was higher than previously found in Finland, and was at a similar level to that of other Nordic countries. In contrast, prevalence of chronic bronchitis was lower than previously shown in Finland.

Adult↗

Different pattern of risk factors for atopic and nonatopic asthma among children--report from the Obstructive Lung Disease in Northern Sweden Study.

BACKGROUND: A cross-sectional study was performed among 78-year-old schoolchildren during the winter of 1996 in three municipalities in the most northern province of Sweden, Norrbotten. The study was the starting point of a longitudinal study of asthma, rhinitis, eczema, and type-1 allergy, and provided data on prevalence and risk factors for these conditions. The aim of the present study was to validate the classification of asthma based on a parental questionnaire, and to examine risk factors for atopic and nonatopic asthma. METHODS: The ISAAC questionnaire with additional questions was distributed by the schools to the parents. The response rate was 97%, and 3431 completed questionnaires were returned. The children in Kiruna and Luleå were also invited to be skin tested, and 2149 (88%) were tested with 10 common airborne allergens. A structured interview was administered by pediatricians in stratified samples of the children to test the validity of the diagnosis of asthma based on the questionnaire. RESULTS: After the validation study, the prevalence of "ever asthma" was estimated to be 8.0%. The specificity of the question, "Has your child been diagnosed as having asthma by a physician?", was high, >99%, while the sensitivity was around 70%. The strongest risk factor for "ever asthma" was a positive skin test (OR 3.9). Risk factors for asthma in the asthmatics who were not sensitized were family history of asthma, OR 3.6; breast-feeding less than 3 months, OR 1.8; past or present dampness at home, OR 1.8; smoking mother, OR 1.7; and male sex, OR 1.6. Among the sensitized asthmatics, only a family history of asthma was a significant risk factor (OR 3.0), while breast-feeding less than 3 months was not associated with an increased risk (OR 1.0). A synergistic effect between genetic and environmental factors was found especially in the nonatopic asthmatics; the children with a family history of asthma who had a smoking mother and past or present dampness at home had an OR for "ever asthma" of 13. CONCLUSIONS: Different risk-factor patterns were found for asthma and type-1 allergy. In addition, the risk factors for atopic or allergic asthma diverged from those for nonatopic asthma.

Asthma↗

Remission of asthma in the middle aged and elderly: report from the Obstructive Lung Disease in Northern Sweden study.

BACKGROUND: Remission of asthma in adults has been considered to be low but is still not well documented. In children remission occurs with a rate estimated at approximately 50%. Remission of asthma in middle aged and elderly subjects was investigated as part of a population based study of respiratory diseases in Northern Sweden. METHODS: In 1986 86% of 6610 subjects participated in a questionnaire survey. After a clinical validation study 300 subjects were diagnosed as having current asthma. In 1996 5935 subjects of the cohort could be traced for a third survey and 87% participated. Of the subjects with current asthma in 1986, 267 participated. In addition, 60 symptomatic subjects were classified as suspected asthma and 58 of them participated in 1996. Remission of asthma was defined as no recurrent wheeze, no attacks of shortness of breath, and no use of asthma medicines in 1996. RESULTS: Remission of asthma during the 10 year period under study was 6%. In subjects with suspected asthma, remission occurred in 22%. The average annual remission rate was less than 1%. Remission was associated with previously mild disease and cessation of smoking. CONCLUSION: Remission of asthma or the disappearance of its symptoms to an asymptomatic latent phase appeared to be rare in middle aged and elderly subjects.

Aged↗

Growth hormone increases aggressive behavior in juvenile rainbow trout.

The aim of the present study was to clarify the role of growth hormone in social interactions in juvenile salmonids. Growth hormone increases the metabolic demands and feeding motivation in teleost fish. As a consequence, growth hormone may increase aggression levels and/or fighting ability. To test these hypotheses we observed agonistic behavior in pairs of juvenile rainbow trout (Oncorhynchus mykiss) consisting of two control fish (C/C pairs), two growth hormone-treated fish (GH/GH pairs), or one growth hormone-treated and one control fish (C/GH pairs). The initiator and the winner of each act of aggression were registered. Aggression was lowest in the C/C pairs, intermediate in the C/GH pairs, and highest in the GH/GH pairs, with the difference between the C/C pairs and the GH/GH pairs being significant. This supports the hypothesis that GH increases aggression levels. However, in the C/GH pairs, the number of conflicts won by GH-treated and control fish did not differ significantly. Thus, because social status was not increased, GH did not appear to affect fighting ability. We suggest that growth hormone affects aggression indirectly by increasing the swimming activity, and/or by inducing defense of a larger territory, thereby increasing the encounter rate between opponents. Since increased aggression can incur energetic and mortality costs, there may be selection against high GH levels in natural populations.

Aggression↗

Are symptoms of obstructive sleep apnoea syndrome related to bronchitic symptoms or lung function impairment? Report from the Obstructive Lung Disease in Northern Sweden Study.

To investigate whether the high prevalence of symptoms related to obstructive sleep apnoea syndrome (OSAS) in a bronchitic cohort is correlated with the bronchitic symptoms or lung function impairment we examined two cohorts with bronchitic symptoms (n = 357 and 82) and a reference group who had reported no respiratory symptoms in a previous survey in 1986 (n = 140). The study was a part of the Obstructive Lung Disease in Northern Sweden Study and included clinical examination and lung function tests. Although lung function measured as FEV1 percentage predicted was correlated with bronchitic symptoms we found that bronchitic symptoms and body mass index but not lung function impairment were correlated with symptoms related to obstructive sleep apnoea. According to our findings it was the various bronchitic symptoms such as longstanding cough, wheezing, sputum production and chronic productive cough that were correlated with OSAS symptoms. This might be due to increased upper airway swelling or increased upper airway resistance, and lung function impairment does not seem to be responsible for the high prevalence of symptoms related to obstructive sleep apnoea in this bronchitic cohort.

Body Mass Index↗

Asthma, type-1 allergy and related conditions in 7- and 8-year-old children in northern Sweden: prevalence rates and risk factor pattern.

As a first step in an intervention study of asthma and allergic diseases among school children, a cross-sectional study was performed during Winter 1996 in three towns (Kiruna, Luleå and Piteå) in the northernmost province of Sweden, Norrbotten. The cross-sectional study aimed to measure the prevalence of asthma, type-1 allergy and allergic diseases in order to make it possible to measure the incidence of the diseases, conditions and symptoms related to the diseases. Another aim was to perform a screening for possible risk factors. All children enrolled in the first and second classes at school, 7 and 8 years old, were invited to take part in this study. The ISAAC questionnaire with added questions about symptoms, morbidity, heredity and environment was distributed by the schools to the parents. The response rate was 97%, and 3431 completed questionnaires were returned. The children in two of the municipalities were also invited to skin test, and 2149 (88%) were tested with 10 common airborne allergens. The results showed that 7% of the children were currently using or had used asthma medicines during the last 12 months. Six percent had asthma diagnosed by a physician, and 4% were using inhaled corticosteroids. The prevalence of wheezing during the last 12 months was 12%, rhinitis without colds 14%, and eczema 27%, while 21% had a positive skin test. The respiratory symptoms and conditions were significantly greater in boys and, further, they were most prevalent in Kiruna in the very north, though not significantly. Type-1 allergy and asthma had different risk factor patterns. The main risk factors for asthma were a family history of asthma (OR = 3.2) followed by past or present house dampness (OR = 1.9), male sex (OR = 1.7) and a smoking mother (OR = 1.6). In Kiruna, when none of these three risk factors were present, none of the children had asthma, but when all three were present, 38% of these children were using asthma medicines.

Analysis of Variance↗

Prevalence and incidence of asthma and rhinoconjunctivitis in Swedish teenagers.

In 1987, we studied the prevalence of asthma and rhinoconjunctivitis in 1112 grade-eight students in the town of Umeå, northern Sweden. The present study is based on the same cohort, reinvestigated in 1991. We aimed to estimate the changes in the prevalence of asthma and rhinoconjunctivitis and to examine some presumed risk factors of asthma and rhinoconjunctivitis. A postal questionnaire on present asthma, rhinoconjunctivitis, symptoms from the upper and lower airways, and the need for medication was used. Questions about living conditions, smoking, and present education were also included. The questionnaire was answered by 89% (990) of the subjects. The prevalence of self-reported asthma was 10.8% (boys 7.9%, girls 13.7%). The incidence rate/year was 1.1%, the remission rate/year was 5.7%, and the relapse rate/year was 10%. The risk factors for developing asthma appeared to be atopy, having a family history of asthma or rhinoconjunctivitis, and smoking. The prevalence of self-reported rhinoconjunctivitis was 14.3% (boys 15.6%, girls 13.1%). The incidence rate/year was 1%, the remission rate/year was 22%, and the relapse rate/year was 11%. Stopping smoking and having no family history of rhinoconjunctivitis or asthma appeared to favor remission in rhinoconjunctivitis.

Adolescent↗

Symptoms related to snoring and sleep apnoea in subjects with chronic bronchitis: report from the Obstructive Lung Disease in Northern Sweden Study.

To assess the relationship between chronic bronchitis and obstructive sleep apnoea, a postal survey was performed. A postal questionnaire was sent to 523 subjects identified as having chronic bronchitis or long-standing cough and sputum production in the Obstructive Lung Disease in Northern Sweden Study I (OLIN I). In 1986-88, all 6610 adults born in 1919-20, 1934-35 and 1949-50 living in representative areas in Northern Sweden were screened for airway diseases according to different methods. A random sample of healthy adults identified in the screening were chosen as references (n = 625). Subjects were asked about a variety of airway symptoms, smoking habits and symptoms related to obstructive sleep apnoea syndrome (OSAS). In the bronchitic group, 20% did not report bronchitic symptoms in the present study, and 26% of the formerly healthy reference group reported at least one bronchitic symptom in the present study. Snoring, apnoea and liability to 'nod off' during activity were much more common in the bronchitic group in both men and women, and most common in men, as expected. Snoring was reported by 29% of the men in the bronchitic group and by 14% in the reference group. In women, the corresponding figures were 14 and 8%, respectively, and for apnoea, the figures were 25 vs. 11% in men and 6 vs. 4% in women. The prevalence of OSAS symptoms was similar in subjects with attacks of breathlessness, long-standing cough, sputum production and recurrent wheezing. Bronchitic symptoms may influence quality of sleep and contribute to daytime tiredness, but this does not fully explain the high prevalence of snoring and apnoea reported by subjects in this cohort. This study indicates a positive correlation between chronic bronchitis and OSAS, but sleep studies are required to confirm this.

Adult↗

Ciliary neurotrophic factor null mutation and schizophrenia in a Swedish population.

According to the maldevelopmental hypothesis, the neurotrophic factor system represents an important area which might be genetically and neurochemically involved in the etiopathogenesis of schizophrenic psychoses. Patients suffering from schizophrenic psychoses and control persons were genotyped for a null mutation of the ciliary neurotropic factor gene. There were no significant differences in the allelic and genotypic distributions in the total schizophrenic and control samples. However, there was a negative association with a family history of psychosis. Thus, it cannot be excluded that this genetic variant represents a vulnerability marker for specific schizophrenic subtypes. The development of valid diagnostic instruments based on biological criteria is crucial for schizophrenia research; more homogeneous subgroups are more likely to represent distinct nosological entities than the heterogenous group of diseases presently categorized as schizophrenia.

Alleles↗