Influence of peroxisome proliferator-activated receptor γ gene polymorphism on 24S-hydroxycholesterol levels in Alzheimer’s patients

The peroxisome proliferator-activated receptor gamma (PPARgamma) is a nuclear hormone receptor, that is involved in lipid and glucose metabolism, which both seem to influence the risk of Alzheimer's disease (AD). 24S-Hydroxycholesterol is the major cholesterol elimination product of the brain and plasma and CSF 24S-hydroxycholesterol levels are altered in patients with neurodegenerative diseases. We investigated the effect of the common Pro12Ala variant of the PPARgamma gene on plasma cholesterol levels and 24S-hydroxycholesterol/ cholesterol ratios in 124 AD patients and 77 healthy controls. Furthermore, the influence of PPARgamma polymorphism on the risk of AD in 247 AD patients and 324 healthy controls was investigated. We found that PPARgamma Pro12Ala polymorphism influenced plasma 24S-hydroxycholesterol/ cholesterol ratios in AD patients in that carriers of the Ala allele presented with higher ratios than homozygote carriers of the Pro-allele. PPARgamma polymorphism did not influence the risk of AD. These results might point to an influence of PPARgamma Pro12Ala polymorphism on the elimination of 24S-hydroxycholesterol.

Polymorphisms in glutathione S-transferase omega-1 and AD, vascular dementia, and stroke

BACKGROUND

Glutathione S-transferase omega-1 (GSTO1) protects from oxidative stress, a risk factor for Alzheimer disease (AD), vascular dementia (VaD), and stroke. Polymorphisms in GSTO1 might influence the function of the protein and thus the risk of AD, VaD, and stroke.

METHODS

The GSTO1 gene was screened for variations. The effect of the detected polymorphisms on the risk of AD, VaD, and stroke was evaluated. CSF levels of cholesterol and plasma homocysteine levels were compared according to the GSTO1 genotype.

RESULTS

Two missense polymorphisms in exon 4 of GSTO1 (Ala140Asp and Glu155DeltaGlu) were detected and tested for their association with AD, VaD, and stroke. The Asp/Asp and Ala/Asp genotypes increased the risk of stroke (p = 0.003, OR = 2.1), and the Asp/Asp genotype increased the risk of VaD (p = 0.02, OR = 2.2). GSTO1 polymorphisms did not influence the risk of AD, but the Asp allele influenced the age at onset (p = 0.05). In nondemented probands CSF levels of cholesterol were increased in carriers of the Asp/Asp genotype (p = 0.004); however, in patients with manifest dementia the authors found decreased CSF levels of cholesterol in carriers of the Asp/Asp genotype (p = 0.028). Serum homocysteine levels in stroke patients were higher in carriers of at least one Asp allele (p = 0.011).

CONCLUSION

The GSTO1 Asp allele may be a genetic risk factor for cerebrovascular diseases, and might influence the course of Alzheimer disease, even though effects vary in different studies.

Identification of somatic and anxiety symptoms which contribute to the detection of depression in primary health care

Somatic symptoms and anxiety symptoms are often disregarded in the detection of depression in primary care. The present investigation examined to what extent somatic and anxiety symptoms recorded with the Composite International Diagnostic Interview-Primary Health Care Version (CIDI-PHC) can improve the detection of depression as compared to the General Health Questionnaire-12-item version alone. Data from the World Health Organization study on Psychological Problems in General Health Care were used. The study sample consisted of primary care attenders from 15 centres from all over the world who underwent a psychiatric examination with the CIDI-PHC. Medically unexplained somatic symptoms (back pain, feelings of heaviness/lightness in parts of the body, periods of bodily weakness, seizures/convulsions, permanent tiredness, exhaustion after a minimum of effort) and-to a smaller extent-diverse anxiety symptoms (e.g. feelings of anxiousness/nervousness, feelings of tension, difficulties relaxing) significantly contributed to the detection of depression in a logistic regression analysis. The results confirm the observation that in primary care somatic symptoms play an important role in the manifestation of depressive disorders. The items investigated herein could prove beneficial for future depression screening instruments to improve the detection of depressive disorders in primary care.

Differences of cerebral activation between superior and inferior learners during motor sequence encoding and retrieval

Cerebral activation during memory encoding and retrieval might depend on subjects' learning capacity, either by corresponding to better performance in superior learners or by reflecting increased effort in inferior learners. To investigate these alternative hypotheses, the study compared cerebral activation during encoding and retrieval of a motor sequence in groups of subjects with superior and inferior learning performances. Ten healthy subjects underwent functional magnetic resonance imaging (fMRI) while performing a motor sequence encoding paradigm (i.e. finger tapping sequence) and a retrieval paradigm (i.e. reproduction of the learned sequence). Subjects were divided into superior and inferior learners according to the correctness of sequence reproduction during retrieval. During encoding, there was strong bilateral activation in the middle frontal gyrus, the supplementary motor area (SMA), the lateral parietal lobe and the cerebellum. During retrieval, again strong activation was found in identical areas of the prefrontal cortex, the parietal lobe and the cerebellum. During encoding, inferior learners showed more left-sided activations in the left middle frontal and inferior parietal gyri. Superior learners showed increased activation in the corresponding right-sided brain areas during encoding as well as during retrieval. Differences of cerebral activations in the prefrontal and parietal cortex during encoding and retrieval were found to be related to retrieval performance, i.e. success and effort. Further intervention studies are needed to assess whether these interindividual differences are the cause or the consequence of differences in memory performance.

No evidence for a genetic relationship between Alzheimer's disease and longevity

OBJECTIVE

Late onset Alzheimer's disease (AD) is frequent in subjects who have reached an age above the average life expectancy. AD and life expectancy are both influenced by genetic factors. Consequently, a possible genetic relationship between AD and longevity was investigated using family study data.

METHODS

First-degree relatives of patients with AD (n = 645) and of non-demented controls (n = 1,106) were examined by direct interview or by family history in the case of already deceased or unavailable subjects. Survival of subjects with an assumed familial load for AD (i.e. first-degree relatives of AD patients) and of controls was compared using the Kaplan-Meier analysis and log-rank statistics.

RESULTS

Relatives with AD reached higher ages than other family members. However, there was no significant co-aggregation of AD and longevity in first-degree relatives of AD patients in comparison with those of controls. This applied to all diseased as well as non-demented relatives.

CONCLUSIONS

Longevity is an independent prerequisite for the development of the disease, but is not genetically related to AD. The apparent longevity in relatives with AD is likely to result from the selection of subjects fulfilling this prerequisite.

Donepezil for Alzheimer's disease in clinical practice--The DONALD Study. A multicenter 24-week clinical trial in Germany

This multicenter open-label clinical trial was designed to investigate the safety and efficacy of donepezil, a selective acetylcholinesterase inhibitor, in the treatment of Alzheimer's disease (AD) in routine clinical practice in Germany. A total of 237 patients with mild-to-moderate AD were treated with donepezil for 24 weeks, 186 completed the study according to the protocol. In the completer group, mean MMSE score for efficacy showed an improvement from baseline of +1.6 points at week 12 (95% CI +1.1 to +2.1) and of +1.1 points at week 24 (95% CI +0.5 to +1.7). In more than 80% of the patients, global tolerability was rated to be very good or good. There were only insignificant effects on ECG parameters. This study confirms the results obtained in previous double-blind trials, which showed that donepezil is effective and well tolerated in patients with mild-to-moderately severe AD.

The methionine synthase polymorphism D919G alters susceptibility to primary central nervous system lymphoma

Primary central nervous system lymphomas (PCNSL) frequently reveal genomic instability. We analysed different functional genetic variants affecting the folate and homocysteine metabolism important for DNA integrity in 31 PCNSL patients and 142 controls. We found significantly less carriers of the methionine synthase c.2756A>G (D919G) missense polymorphism among the patients (0.16 vs 0.42; odds ratio 0.26, CI(95%): 0.09-0.74; P=0.005), suggesting a protective function of the G allele. These data stimulate further epidemiological and functional studies focusing on the role of homocysteine and folate metabolism in lymphoma tumorigenesis.

Response-related fMRI of veridical and false recognition of words

OBJECTIVES

Studies on the relation between local cerebral activation and retrieval success usually compared high and low performance conditions, and thus showed performance-related activation of different brain areas. Only a few studies directly compared signal intensities of different response categories during retrieval. During verbal recognition, we recently observed increased parieto-occipital activation related to false alarms. The present study intends to replicate and extend this observation by investigating common and differential activation by veridical and false recognition.

METHODS

Fifteen healthy volunteers performed a verbal recognition paradigm using 160 learned target and 160 new distractor words. The subjects had to indicate whether they had learned the word before or not. Echo-planar MRI of blood-oxygen-level-dependent signal changes was performed during this recognition task. Words were classified post hoc according to the subjects' responses, i.e. hits, false alarms, correct rejections and misses. Response-related fMRI-analysis was used to compare activation associated with the subjects' recognition success, i.e. signal intensities related to the presentation of words were compared by the above-mentioned four response types.

RESULTS

During recognition, all word categories showed increased bilateral activation of the inferior frontal gyrus, the inferior temporal gyrus, the occipital lobe and the brainstem in comparison with the control condition. Hits and false alarms activated several areas including the left medial and lateral parieto-occipital cortex in comparison with subjectively unknown items, i.e. correct rejections and misses. Hits showed more pronounced activation in the medial, false alarms in the lateral parts of the left parieto-occipital cortex.

CONCLUSIONS

Veridical and false recognition show common as well as different areas of cerebral activation in the left parieto-occipital lobe: increased activation of the medial parietal cortex by hits may correspond to true recognition, increased activation of the parieto-occipital cortex by false alarms may correspond to familiarity decisions. Further studies are needed to investigate the reasons for false decisions in healthy subjects and patients with memory problems.

Putative association of polymorphism in the mannose 6-phosphate receptor gene with major depression and Alzheimer's disease

The endosomal lysosomal system might play a role in Alzheimer's disease, but its impact in major depression is unknown. The expression of the cation-dependent mannose 6-phosphate receptor (CD-MPR) is increased in Alzheimer's disease and the CD-MPR gene is located next to a region on chromosome 12 possibly linked to Alzheimer's disease. We investigated a C/T polymorphism in the CD-MPR gene in 188 Alzheimer's disease patients, in a control sample of 193 patients with major depression, as hospitalized controls, and in 259 healthy controls. We examined the interaction of the CD-MPR polymorphism with the putative risk factor for Alzheimer's disease, the cathepsin D T-allele. No significant association of the CD-MPR C-allele with Alzheimer's disease was observed. However, exploratory data analysis revealed an increased frequency of the CD-MPR C-allele in patients with major depression; thus, the C-allele may be a risk factor for depression. Gene location and function of the CD-MPR suggest an involvement in Alzheimer's disease; however, we could not find an association of the CD-MPR polymorphism with Alzheimer's disease. Since exploratory data suggest an involvement of the endosomal lysosomal system in major depression, further studies are warranted to investigate the biological role of the CD-MPR in major depression.

Mixed anxiety-depression in a 1 year follow-up study: shift to other diagnoses or remission?

BACKGROUND

In 1992, the ICD-10 introduced the concept of mixed anxiety-depression disorder (MAD). However, a study examining the stability of this ICD-10-diagnosis is lacking. Our objective was to examine the 12 month outcome of MAD in comparison to the outcome of depression, anxiety, and comorbid depression and anxiety.

METHODS

85 MAD patients, 496 patients with major depression, 296 patients with anxiety disorders, and 306 comorbid patients were reassessed after 12 months. Rates of depression, anxiety, and MAD were compared using chi(2)-tests.

RESULTS

While depressive disorders and anxiety disorders showed relatively high stability, MAD Patients had no higher rates of MAD at follow-up than patients with depression, anxiety or both.

LIMITATIONS

Detailed information regarding treatment and disorders during the follow-up interval was lacking. Prevalence rates of MAD in single centres were too small for contrasting centres.

CONCLUSIONS

MAD cannot be seen as a stable diagnosis: Most of MAD patients remit; many of them shift to other diagnoses than depression or anxiety. The ICD-10 criteria have to be specified more exactly.

Subjective memory complaints of family members of patients with Alzheimer's disease and depression

BACKGROUND

First-degree relatives of patients with Alzheimer's disease (AD) and major depression (MD) carry an increased genetic risk for the same disorders. Subjective memory complaints of the family members of patients might be an early sign or an indicator of an increased risk of either dementia or depression. Alternatively, they might be the consequence of the increased subjective awareness of relatives and spouses of patients of their own age-associated memory failures. To investigate the relevance of the above-mentioned hypotheses, the prevalence rates of subjective memory complaints of first-degree relatives and spouses of patients with AD, of patients with MD and of control subjects were compared.

METHODS

Personal interviews were conducted with 718 first-degree relatives and 196 spouses of 146 AD patients, 168 patients with MD and 136 control subjects from the general population. The prevalences of subjective memory complaints by relatives or spouses were compared using chi(2) tests. To control for differences of gender and age at onset, Cox proportional hazards analyses were performed.

RESULTS

There were no differences in the prevalence of subjective memory complaints by first-degree relatives of subjects with AD, MD and controls after controlling for age differences. The same applies to the subjective memory complaints in their spouses.

CONCLUSION

Subjective memory complaints were frequent in family members. However, they were neither associated with the genetic risk of AD or of MD nor could they be explained by an increased awareness by having a demented spouse or relative. Consequently, familial factors seem to have a limited influence on the presence of subjective memory complaints in the elderly.

The role of 24S-hydroxycholesterol in Alzheimer's disease

Studies on Alzheimer's disease (AD) revealed that cholesterol metabolism might be involved in the pathogenesis of this neurodegenerative disorder. The apolipoprotein E4 genotype is a known risk factor in AD. Elevated serum cholesterol concentrations are detected in patients with AD and two recent epidemiological studies have indicated that treatment with inhibitors of cholesterol synthesis (statins) decrease the incidence of AD. 24R- and 24S-hydroxycholesterol, the major cholesterol elimination product of the brain, possess neurotoxic effects in vitro, and increased concentrations of 24S-hydroxycholesterol have been detected in patients from our department, suggesting a role for this oxysterol in the pathogenesis of AD. This review will give a brief overview on the relevance of 24S-hydroxycholesterol as a possible risk factor and diagnostic state marker for AD.

Risk factors for depression at 12-month follow-up in adult primary health care patients with major depression: an international prospective study

BACKGROUND

The aim of this study was to identify internationally relevant risk factors for the persistence of depression in primary care. None of the previous studies examining primary care patients could examine an equivalently large international sample. The findings from the WHO Collaborative Study on 'Psychological Problems in General Health Care' might be generalised to different cultural environments.

METHODS

A primary care sample of depressed subjects (ICD-10) (n=725) from 15 centres from all over the world was reinvestigated for the presence of depression after 12 months. Logistic regression analysis was used to determine the relationship of sociodemographic variables, characteristics of mental illness, and social disability with depression at follow-up.

RESULTS

33.5% of the subjects met ICD-10 criteria for a current depressive episode at the 12-month follow-up. Logistic regression analysis revealed that years of formal education, unemployment, depression severity, antidepressant use, abdominal pain as the main reason for consulting the general practitioner, and 'Repeated suicidal thoughts' were related to depression after 1 year.

LIMITATIONS

We have only poor information about details of the actual course of patients between the two assessments.

CONCLUSIONS

Our findings of significant variables are generally comparable to results of previously conducted studies. Sociodemographic and disease-specific variables play an important role in the prediction of depression at the 12-month follow-up. General practitioners must be careful in the consideration of these variables but also of individual patient characteristics.

Polymorphism in the peroxisome proliferator-activated receptor alpha gene influences the risk for Alzheimer's disease

The peroxisome proliferator-activated receptor alpha (PPAR-alpha) is a member of the steroid hormone super family of ligand-inducible transcription factors, involved in glucose and lipid metabolism. We screened for polymorphisms in the PPAR-alpha gene and detected two known polymorphisms located in exon 5 and intron 7. These polymorphisms were investigated for their possible association with Alzheimer's disease (AD) and for their effect in carriers of an insulin gene (INS) polymorphism. The PPAR-alpha C --> G polymorphism in exon 5 (L162V) was associated with AD, in that the V-allele was more frequent in AD patients than in healthy subjects. Further data analysis revealed that carriers of an PPAR-alpha L162V V-allele and an INS-1 allele presented with an increased risk for AD. Cerebrospinal fluid amyloid-beta levels were influenced by PPAR-alpha L162V genotype. These results suggest, that PPAR-alpha polymorphism may be a risk factor for AD.

Association of the C766T polymorphism of the low-density lipoprotein receptor-related protein gene with Alzheimer's disease

The low-density lipoprotein receptor-related protein (LRP) is one of the most important cholesterol receptors in the brain. Gene variation of its ligand, apolipoprotein E, is a major genetic risk-factor for Alzheimer's disease (AD). The C-allele of the silent C766T polymorphism in exon 3 of the LRP gene might be associated with AD, however, results are conflicting and thus discussed controversially. Consequently, we compared the prevalence of this polymorphism in a homogenous cohort of patients with AD and control subjects. We found that carriers of a C-allele were at lower risk of AD; in agreement with this observation, AD patients who were carriers of a C-allele presented with a later age at onset of the disease than carriers of the TT genotype. These data suggest that LRP polymorphism influences the risk as well as the age at onset of AD. Our results contrast with other studies which described the C-allele to be a risk-factor for AD, but are in line with a recent publication on the effect of LRP polymorphism on longevity and on the risk for coronary artery disease. Further research on LRP polymorphisms is needed to evaluate their effects on the risk of AD, on coronary artery disease and on longevity.

Mortality in Alzheimer's disease

OBJECTIVE

This study examines the relevance of variables suspected to influence mortality in Alzheimer's disease (AD).

METHODS

172 subjects with AD recruited through a family study were followed up for a mean of 4.7 +/- 2.6 years. Their survival was compared with that of matched control subjects using Kaplan-Meier and log-rank statistics. Variables determining mortality were examined with the Cox proportional hazards model.

RESULTS

Survival in subjects with AD depended on age, the severity of cognitive decline and on the incidence of hospitalisation. Gender, the duration of the illness, the velocity of cognitive decline, the allele E4 of the apolipoprotein E genotype and the presence of other lifetime psychiatric diagnoses did not influence mortality.

CONCLUSION

Mortality in AD depended mainly on the subjects' age and the severity of the disorder.

Polymorphism in the BACE gene influences the risk for Alzheimer's disease

Pathological characteristics of Alzheimer's disease (AD) are neurofibrillary tangles and amyloid-beta (Abeta) plaques. Abeta is generated by cleavage of the amyloid precursor protein by beta- and gamma-secretases. BACE (beta-site APP cleaving enzyme) was identified as the beta-secretase. Variations of the BACE gene might influence activity and function of the protein and, thus, might influence the pathogenesis of AD. Consequently, we investigated the association of different BACE polymorphisms with AD. BACE exon 5 polymorphism influenced the risk of AD. This effect was most pronounced in apolipoprotein E4 allele carriers. Furthermore, Abeta(42) CSF levels were influenced by BACE genotype. It appears that BACE polymorphism plays a more important role in the development of AD than previously assumed, possibly by influencing Abeta(42) levels.

Reduced hippocampal activation during encoding and recognition of words in schizophrenia patients

OBJECTIVE

In patients with schizophrenia, impaired hippocampal activation either during encoding or recognition tasks has been observed in a few functional imaging experiments. In this fMRI study, the authors report results of word encoding and recognition in schizophrenia patients and healthy comparison subjects, with a special focus on correcting for behavioral recognition success in order to prevent a bias related to lower task performance in the schizophrenia patients.

METHOD

The verbal encoding and recognition tasks were both first analyzed irrespective of recognition success. In a second analysis, recognition success was included in the block-designed encoding task as a covariate of no interest, and incorrectly classified items were rejected from the analysis of the event-related recognition task.

RESULTS

Patients performed poorer on the recognition task than the comparison subjects. Bilateral hippocampal activation during encoding and recognition was observed in both groups. Right hippocampal activation in patients during recognition became significant only after exclusion of wrongly classified items. Group comparison revealed greater activation in the healthy comparison subjects in the left anterior hippocampus during encoding and bilaterally during recognition. Greater bilateral hippocampal activation in the healthy subjects and greater activation in the right anterior hippocampus in the schizophrenic patients were revealed after presentation of novel words, which were intermixed with previously encoded words in the recognition task. After exclusion of incorrectly classified items, the differences in the right hippocampus remained significant.

CONCLUSIONS

This study provides evidence for disturbed hippocampal function during verbal encoding and recognition in patients with schizophrenia. It extends previous studies by correcting for the possible confound of differences in behavioral task performance. This approach further supports the concept of hippocampal dysfunction in schizophrenia.

Investigation of a genetic variation of a variable number tandem repeat polymorphism of interleukin-6 gene in patients with multiple sclerosis

Interleukin-6 (IL-6) plays an important role in the regulation of the inflammatory response in multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). Previous reports indicated that the C allele of a variable number tandem repeat (vntr) polymorphism located in the 3'flanking region of the IL-6 gene ( IL-6) is associated with reduced activity of IL-6 in vivo. Since disease-modifying genes are likely to contribute to phenotypic differences in MS patients, we tested the hypothesis that the IL-6 C allele is associated with the clinical course of MS. The IL-6 C allele was equally distributed between 217 MS patients of German Caucasian origin and 111 age-mached healthy controls. Stratification of patients according to the course of disease revealed no significant difference of IL-6 C allele distribution between patients with primary progressive and those with either relapsing-remitting or secondary progressive MS although IL-6 C allele was more frequent in patients with RR-MS. Since IL-6 C allele has been associated with a benign course in Sardinian MS patients, we further analysed an independent sample of 125 Sardinian MS patients revealing that IL-6 C allele was much more frequent than in German MS patients. Taken together, a disease-modifying effect of IL-6 C allele could not be demonstrated in MS patients of German Caucasian descent.

Lifetime symptoms of depression in Alzheimer's disease

INTRODUCTION

Depression is common in Alzheimer's disease (AD). The symptomatology of depression in dementia may differ from depression alone. Consequently, the reports on lifetime depressive symptoms were compared in AD patients and age-matched non-demented participants.

METHODS

Seventy-six AD patients, 109 elderly from the general population and their 189 siblings were examined using the Composite International Diagnostic Interview (CIDI). The presence of individual lifetime depressive symptoms was compared between 76 AD patients, 29 AD patients with comorbid depression, and different control groups using chi(2) statistics and logistic regression analysis.

RESULTS

Lifetime depressive symptoms were significantly more frequent in 76 AD patients than in 109 age-matched elderly from the general population. These 76 AD patients complained more about thinking and concentration disturbances, and less about depressed mood or appetite disturbance than the 298 non-demented participants matched for the lifetime presence of major depression (MD). In agreement, the 29 patients comorbid for lifetime diagnoses of AD and MD reported less about depressed mood than the 114 age-matched elderly with MD only. Feelings of worthlessness and suicidal ideas were related to the severity of cognitive decline.

CONCLUSION

AD influences the reports on lifetime depressive symptoms. This may be caused by additional neurodegeneration, by an overlap of symptoms of depression and dementia or by an altered perception of mood disturbances in AD. Further studies should investigate these alternatives.

CYP2D6 polymorphism and tardive dyskinesia in schizophrenic patients

Antipsychotic drug-induced tardive dyskinesia (TD) is a serious problem during psychopharmacologic treatment of schizophrenic patients. In search of genetic factors contributing to TD, there is a lack of consensus regarding the role of the polymorphic isozyme cytochrome P450 CYP2D6, which is involved in the oxidative metabolism of antipsychotic drugs. In the present case-control study, we tested the putative influence of the CYP2D6 genotype on the development of TD. Out of 157 patients, 109 were retrospectively selected meeting DSM IV criteria for schizophrenia or schizoaffective disorder, and 50 of them persistently presenting with TD. Genotyping detected the functional allele CYP2D6 *1, the known major defective alleles CYP2D6 *3, *4, *5, *6, and gene duplication. According to their number of functional CYP2D6 alleles, subjects were divided into carriers of none, one, or at least two functional CYP2D6 alleles. The proportions of these categories did not differ between patients and an ethnically homogenous control population (n = 195, p = 0.99) or between patients with and without TD (p = 0.818). Schizophrenic patients were carriers of gene duplication more often than healthy probands, without revealing statistical significance (p = 0.10). Out of seven patients with gene duplication, three developed persistent TD. Furthermore, patients with and without TD were comparable according to age, age of onset, gender, and duration of illness, but subjects with TD had taken more lifetime chlorpromazine equivalents (CPZ) than had patients without TD (chi 2-test, Student's t-test). Forward as well as backward logistic regression analyses confirmed that the presence of TD was influenced by lifetime CPZ but not by age, age of onset, gender, duration of illness, or CYP2D6 genotype. In contrast to the relevance of lifetime CPZ, the lifetime dose of antipsychotic drugs known to be metabolized by CYP2D6 did not significantly influence the presence of TD. In conclusion, our results provide no evidence for the contribution of CYP2D6 genotype to the development of TD in schizophrenic patients receiving long-term antipsychotic medication.

[The 4-week prevalence of somatoform disorders and associated psychosocial impairment]

In the course of a WHO study,we report on the prevalence of somatoform disorders (SFD) and the associated psychosocial impairment in five western German primary care settings. In accordance with ICD-10 classification, a 4-week prevalence of 28.5% was found for SFD (number of patients in the age between 18 and 60 with an SFD in the last 28 days). The accumulation of SFD was higher in female patients than in males (RR 1.7), in particular when the number of children was >1 (RR 1.8). The female-male difference was more marked in persistent somatoform pain disorder (RR 2.1) and unspecific somatization disorder (RR 5.0). Concerning other psychiatric disorders, neurasthenia occurred most frequently,with a 4-week prevalence of 8.2%. The 4-week prevalence of concomitant occurrence of SFD and other psychiatric disorders was 7.7%. Working capability was most severely impaired, with 22.5 days of absence from work during the last month, in male patients with hypochondriacal disorder. In comparison, somatization disorder resulted in a severe level of psychosocial impairment, with 10.3 days of absence in work during the last month in female patients. The coexistence of SFS with other psychiatric disorders resulted in a greater extent of psychosocial impairment.

Polymorphism in the cholesterol 24S-hydroxylase gene is associated with Alzheimer's disease

Cholesterol and 24S-hydroxycholesterol are involved in the pathogenesis of Alzheimer's disease (AD). Increased serum cholesterol concentrations have been detected in patients with AD. 24S-Hydroxycholesterol is the primary cholesterol elimination product of the brain and possesses neurotoxic properties in vitro. The enzyme catalyzing the conversion of cholesterol to 24S-hydroxycholesterol, cholesterol 24S-hydroxylase (CYP46), is mainly expressed in neurons. Concentrations of 24S-hydroxycholesterol in cerebrospinal fluid (CSF) and serum differ significantly between AD patients and non-demented subjects. To test the hypothesis if polymorphisms in the CYP46 gene might influence the function of the respective enzyme and thus cholesterol metabolism in the human brain, we screened for polymorphisms in 114 AD patients and 144 healthy controls. Two intronic single nucleotide polymorphisms were observed and their allelic distribution was investigated. In our study sample, carriers of the C allele of the IVS3+43C --> T polymorphism were more prevalent in the group of AD patients than in healthy controls, while another IVS2-150A --> G polymorphism did not show a significant association with AD. The CC genotype of the IVS3+43C --> T polymorphism was associated with an increased 24S-hydroxycholesterol/cholesterol ratio in the CSF of AD patients. Our results indicate that the CYP46 gene locus may predispose to AD by increasing the 24S-hydroxycholesterol/cholesterol ratio in the brain.