Polypharmacy in psychiatry and weight gain: longitudinal study of 832 patients hospitalized for depression or schizophrenia, along with data of 3180 students from Europe, the U.S., South America, and China

Epidemiologic data indicate that overweight and obesity are on the rise worldwide. Psychiatric patients are particularly vulnerable in this respect as they have an increased prevalence of overweight and obesity, and often experience rapid, highly undesirable weight gain under psychotropic drug treatment. Current treatment strategies in psychiatry are oriented towards polypharmacy, so that the information on drug-induced weight gain from earlier monotherapy studies is of very limited validity. We have analyzed the longitudinal data of 832 inpatients with ICD-10 diagnoses of either F2 (schizophrenia; n = 282) or F3 (major depression; n = 550) with the goal of ranking treatment regimens in terms of weight gain, side effects, and response to treatment. The patient data were complemented by the data of 3180 students aged 18-22 years, with which we aimed to identify factors that enable the early detection and prevention of obesity and mental health problems. After 3 weeks of treatment, 47.7% of F2 patients and 54.9% of F3 patients showed a weight gain of 2 kg and more. Major predictive factors were "starting weight" (r = 0.115), "concurrent medications" (r = 0.176), and "increased appetite"(r = 0.275). Between 11 and 30% of the observed variance in weight gain could be explained by these factors, complemented by sex and age. The comparison between monotherapy (n = 409) and polypharmacy (n = 399) revealed significant drawbacks for polypharmacy: higher weight gain (p = 0.0005), more severe side effects (p = 0.0011), and lower response rates (F2: p = 0.0008); F3: p = 0.0101). The data of 3180 students made it clear that overweight and obesity often begin early in life among those affected, and are interconnected with personality traits, while increasing the risk of developing psychosomatic disturbances, mental health problems, or somatic illnesses. Although the available data did not readily lead to a comprehensive, clinically applicable model of unwanted weight gain, our results have nevertheless demonstrated that there are ways to successfully counteract such weight gain at early stages of treatment.

Analysis of genetic diversity in patients with major psychiatric disorders versus healthy controls: A molecular-genetic study of 1698 subjects genotyped for 100 candidate genes (549 SNPs)

BACKGROUND

This study analyzed the extent to which irregularities in genetic diversity separate psychiatric patients from healthy controls.

METHODS

Genetic diversity was quantified through multidimensional "gene vectors" assembled from 4 to 8 polymorphic SNPs located within each of 100 candidate genes. The number of different genotypic patterns observed per gene was called the gene's "diversity index".

RESULTS

The diversity indices were found to be only weakly correlated with their constituent number of SNPs (20.5 % explained variance), thus suggesting that genetic diversity is an intrinsic gene property that has evolved over the course of evolution. Significant deviations from "normal" diversity values were found for (1) major depression; (2) Alzheimer's disease; and (3) schizoaffective disorders. Almost one third of the genes were correlated with each other, with correlations ranging from 0.0303 to 0.7245. The central finding of this study was the discovery of "singular genes" characterized by distinctive genotypic patterns that appeared exclusively in patients but not in healthy controls. Neural Nets yielded nonlinear classifiers that correctly identified up to 90 % of patients. Overlaps between diagnostic subgroups on the genotype level suggested that (1) diagnoses-crossing vulnerabilities are likely involved in the pathogenesis of major psychiatric disorders; (2) clinically defined diagnoses may not constitute etiological entities.

CONCLUSION

Detailed analyses of the variation of genotypic patterns in genes along with the correlation between genes lead to nonlinear classifiers that enable very robust separation between psychiatric patients and healthy controls on the genotype level.

Detailing the effects of polypharmacy in psychiatry: longitudinal study of 320 patients hospitalized for depression or schizophrenia

Current treatment standards in psychiatry are oriented towards polypharmacy, that is, patients receive combinations of several antidepressants, antipsychotics, mood stabilizers, anxiolytics, hypnotics, antihistamines, and anticholinergics, along with other somatic treatments. In tandem with the beneficial effects of psychopharmacological drug treatment, patients experience significant adverse reactions which appear to have become more frequent and more severe with the rise of ubiquitous polypharmacy. In this study, we aimed to assess today's acute inpatient treatment of depressive and schizophrenic disorders with focus on therapeutic strategies, medications, adverse side effects, time course of recovery, and efficacy of treatments. Of particular interest was the weighing of the benefits and drawbacks of polypharmacy regimens. We recruited a total of 320 patients hospitalized at three residential mental health treatment centers with a diagnosis of either schizophrenic (ICD-10: "F2x.x"; n = 94; "F2 patients") or depressive disorders (ICD-10: "F3x.x"; n = 226; "F3 patients"). The study protocol included (1) assessment of previous history by means of the SADS Syndrome Check List SSCL-16 (lifetime version); (2) repeated measurements over 5 weeks assessing the time course of improvement by the Hamilton Depression Scale HAM-D and the Positive and Negative Syndrome Scale PANSS, along with medications and adverse side effects through the Medication and Side Effects Inventory MEDIS; and (3) the collection of blood samples from which DNA and serum were extracted. Polypharmacy was by far the most common treatment regimen (85%) in this study. On average, patients received 4.50 ± 2.68 medications, consisting of 3.30 ± 1.84 psychotropic drugs, plus 0.79 ± 1.13 medications that alleviate adverse side effects, plus 0.41 ± 0.89 other somatic medications. The treating psychiatrists appeared to be the main determining factor in this context, while «previous history» and «severity at baseline» played a minor role, if at all. Adverse drug reactions were found to be an inherent component of polypharmacy and tended to have a 2-3 times higher incidence compared to monotherapy. Severe adverse reactions could not be attributed to a particular drug or drug combination. Rather, the empirical data suggested that severe side effects can be triggered by virtually all combinations of drugs, provided patients have a respective vulnerability. In terms of efficacy, there were no advantages of polypharmacy over monotherapy. The results of this study underlined the fact that polypharmacy regimens are not equally suited for every patient. Specifically, such regimens appeared to have a negative impact on treatment outcome and to obfuscate the "natural" time course of recovery through a multitude of interfering factors. Evidence clearly speaks against starting just every therapeutic intervention in psychiatry with a combination of psychopharmaceuticals. We think that it is time for psychiatry to reconsider its treatment strategies, which are far too one-sidedly fixated on psychopharmacology and pay far too little attention to alternative approaches, especially in mild cases where psychotherapy without concurrent medication should still be an option. Also, regular exercises and sports can definitely be an effective therapeutic means in a considerable number of cases. General practitioners (GPs) are particularly in demand here.

Inflammatory processes linked to major depression and schizophrenic disorders and the effects of polypharmacy in psychiatry: evidence from a longitudinal study of 279 patients under therapy

Over the past 2 decades, polypharmacy has become the de-facto standard of acute treatment in psychiatry where patients with psychiatric disorders receive a multiple medication regimen. There is growing evidence for a potential link between major psychiatric disorders and inflammatory processes. Combining these two aspects aims at avoiding polypharmacy attempts among patients with inflammatory activation through alternative treatment strategies. In this study, we addressed the following questions: (1) to what extent can polypharmacy be explained through the factors "diagnosis", "previous history", "severity at baseline", "age", "gender", and "psychiatrist in charge"; (2) what are the differences between polypharmacy and monotherapy regarding efficacy and side effect profiles; and (3) what amount of between-patient variance is explainable by the natural antibody immunoglobulin M (IgM) within each diagnostic group. This naturalistic longitudinal study was comprised of 279 patients under therapy with a clinical diagnosis of depressive (ICD-10: "F3x.x"; n = 195) or schizophrenic disorders (ICD-10: "F2x.x"; n = 84). The study protocol included (1) assessment of previous history by the SADS Syndrome Check List SSCL-16 (lifetime version); (2) repeated measurements over 5 weeks assessing the time course of improvement by the Hamilton Depression Scale HAM-D and the Positive and Negative Syndrome Scale PANSS, along with medication and unwanted side effects through the Medication and Side Effects Inventory MEDIS; and (3) the collection of blood samples from which DNA and serum were extracted. The association between inflammatory response system and psychiatric disorders was detailed by fitting multi-layer Neural Net (NN) models to the observed data ("supervised learning"). The same approach was used to set up prediction models of side effects. Our data showed that polypharmacy was omnipresent. Yet the various polypharmacy regimens had no advantage over monotherapy: we even found slightly larger baseline score reductions under monotherapy, independent of primary diagnoses and for comparable baseline severities. Most patients experienced unwanted side effects. The close link between side effects and treatment regimen was revealed by a linear model in which the mere number of drugs explained a significant (p < 0.001) proportion of the observed variance. As to the inflammatory response system: For the F2 patients, our NN model identified a 22.5% subgroup exhibiting a significant correlation of r = 0.746 (p = 0.0004) between global schizophrenia scores and IgM levels, along with a correct prediction of response of 94.4%, thus explaining 55.7% of the observed between-patient variance. For the F3 patients, our NN model identified a 19.6% subgroup exhibiting a significant correlation of r = 0.644 (p = 0.00003) between global depression scores and IgM levels, along a correct prediction of response of 89.6%, thus explaining 41.4% of the observed between-patient variance. Polypharmacy is omnipresent in today's acute treatment of psychiatric disorders. Given the large proportion of patients with unwanted side effects and the strong correlation between side effects and the number of drugs, polypharmacy approaches are not equally suited for every patient. In terms of efficacy, there are no advantages of polypharmacy over monotherapy. Most notably, our study appears to have cleared the way for the reliable identification of a subgroup of patients for whom the inflammatory response system is a promising target of therapeutic intervention.

Onset of improvement under fluoxetine and moclobemide

In a meta-analysis of the selective serotonin reuptake inhibitor fluoxetine (n = 440) and the reversible and selective monoamine oxidase-A inhibitor moclobemide (n = 437) we investigated the time course of improvement over 6 weeks for these two classes of anti-depressants. Two different methods of approach were applied: (1) repeated measurement analysis of variance in combination with regression analysis, and (2) a survival-analytical approach that allowed us to determine onset of improvement for the individual patient, to distinguish between early and late improvers, to assess the predictive value of early improvement, and to adequately process premature withdrawals. The two antidepressants of large biochemical and pharmacological differences yielded virtually identical response- and drop-out rates, and exhibited no difference with respect to the time course of improvement. Onset of improvement occurred in more than half of the patients within the first 2 weeks of treatment, and early improvement was highly predictive of later outcome. In particular, there was no indication for a delayed onset of action of antidepressants. We suggest that future studies should be standardised with respect to washout period and sufficiently dense assessments during the first 2 weeks of trial. Thus, patient samples can be subdivided reproducibly into early-, late-, partial- and non-remitters. This, in turn, may help to identify “true” drug responders, and to discover why in some patients recovery becomes “stuck”. Data already held by the pharmaceutical companies should be reanalysed in this respect.

Masking Artifacts in EEG Time Series

The removal of artifacts from EEG time series by masking the concerned parts has been studied in order to derive error estimates which apply in general. For this purpose, we selected a sufficiently representative set of artifact-free time series registered from 81 individuals. These time series then served as error-free references. Subsequently, we used the same set of time series, simulated artifacts of 2-12 seconds length (each of which at 5 different positions within each epoch) and investigated the impact of masking procedures on spectrum analysis. Our interest focused particularly on clearing up possble sources of variation (e. g., the actual frequency composition of the signal or the actual position of the masked segment within the time series) in theerrors inherent in the masking process. A detailed error analysis yielded no indication that the inherent errors depend on such factors. Moreover, it turned out that any sufficiently representative set of, say, about 100 epochs of 20 seconds length can be used to reproduce all required estimates at an errorof less than 5 percent. Based on these findings, we developed a correction function which applies in general, thus simplifying the fully computerized processing of EEG time series.

Affective State and Voice: Reproducibility and Sensitivity of Speech Parameters

In 1986, we started an extensive investigation into the nonverbal information transmitted in human speech. As part of this investigation, we had designed a study of healthy subjects -stratified according to sex, age and education - in order to gain valuable insights into the “typical” nonverbal activities of a speaker. The specific design of this study with 3 different types of texts and 2 repeated measurements at an interval of 14 days was used to test the stability of speech parameters over time as well as their sensitivity to form and content of text. In a first approach, we directed our efforts towards a set of major scalar quantities which earlier investigators had described as playing a key role in modelling affect in terms of directly measurable speech parameters.

Based on a sample of 97 persons and with the help of a fully computerized digital approach to speech processing, we found that the four major speech parameters “mean vocal pitch”, “time duration of pauses”, “time duration of utterances”, and “energy” are sufficiently reproducible under constant experimental conditions, whereas some significant differences showed up with regard to the sensitivity of these parameters to form and content of the spoken text. No substantial impact originated from the external factors sex, age and education, except for the tonal shift of one octave between males and females.

On the other hand, the overwhelming variety of individual voice patterns obviously excludes any simple model (which applies in general) of the nonverbal component of human speech. However, our analyses offered some important clues as to how appropriate models may be derived by means of adaptive procedures.

The Similarity Approach to EEG Analysis

A method of approach to EEG analysis has been proposed which is based upon the concept of similarity. It especially aims at the analysis of the between-subject and within-subject similarity of EEG spectral patterns by means of adaptive procedures. Repeated measurements from the same individual were used as design samples, and new registrations after 14 days were referred to as test samples in order to determine the calibration parameters of the approach. The discrimination between the distributions of between-subject and within-subject similarity coefficients served as the criterion for the optimization algorithm. The optimization was terminated when the discriminating power reached 92% for both design samples and test samples. Accordingly, EEG spectral patterns were found to measure the distinct individuality of the EEG with good precision and to be stable over time.

Consequently, a detailed analysis of the between-subject similarities by evaluating the fine graduations of mutual differences was of special interest. The realization of this idea led to a methodological problem because all basic information existed only in the form of non-metric similarity matrices. The problem was solved by means of a non-metric MDS which led to a geometric representation of the relational data. The final configuration of image points suggested a partitioning into 4 natural groupings comprising about ¾ of the samples. The remaining measurements were either isolated elements or formed smaller clusters whose relevance remained undecided. Contrary to traditional EEG classifications, this approach provided not only abstract clusters but also the positions of patterns within clusters and the relative positions of clusters to each other. The latter seems to be important in connection with the analysis of reactive changes in the human EEG, particularly because other investigations have shown that the effects of centrally acting substances are highly dependent upon the specific type of EEG.

Affective State and Voice: The Specific Properties of Overtone Distributions

Motivated by psychiatric interests and as part of our investigations into the basic properties of human speech, we carried out a normative study with 192 healthy subjects - stratified according to sex, age and education - in order to derive reference values of the general population and to learn to distinguish between normal fluctuations and significant changes over time. In the present investigation, our interest focused on the individual sound characteristics of speakers (“timbre”) rather than on speech behavior. Accordingly, we determined the optimum parameter setting for a problem-specific, reliable estimation of time dependent spectra. An interval of one second length was found to be optimum for reproducibly assessing formants and corresponding band-widths for more than 95% of the cases. Based on these findings, we adapted the concept of “spectral patterns” to speech analysis. It turned out that spectral voice patterns are stable over time and measure the fine graduations of mutual differences between human voices. A highly reliable computerized recognition of persons was possible by means of these quantities, on the basis of 16-32 s time series: 93% of persons could be uniquely recognized after a 14-day interval. Hence, we succeeded in developing specific means for modelling intra-individual changes of voice timbres over time. This is of particular interest for investigations of the speech characteristics of affectively disturbed patients, since the tonal expressiveness of human voices, or the lack thereof, essentially depends on the actual distribution of overtones and the corresponding variabilities.

The octave approach to EEG analysis

A “tonal” approach to EEG spectral analysis is presented which is compatible with the concept of physical octaves, thus providing a constant resolution of partial tones over the full frequency range inherent to human brain waves, rather than for equidistant frequency steps in the spectral domain. The specific advantages of the tonal approach, however, mainly pay off in the field of EEG sleep analysis where the interesting information is predominantly located in the lower octaves. In such cases the proposed method reveals a fine structure which displays regular maxima possessing typical properties of “overtones” within the three octaves 1-2 Hz, 2-4 Hz and 4-8 Hz. Accordingly, spectral patterns derived from tonal spectral analyses are particularly suited to measure the fine gradations of mutual differences between individual EEG sleep patterns and will therefore allow a more efficient investigation of the genetically determined proportion of sleep EEGs. On the other hand, we also tested the efficiency of tonal spectral analyses on the basis of our 5-year follow-up data of 30 healthy volunteers. It turned out that 28 persons (93.3%) could be uniquely recognized after five years by means of their EEG spectral patterns. Hence, tonal spectral analysis proved to be a powerful tool also in cases where the main EEG information is typically located in the medium octave 8-16 Hz.

Intraindividual Specificity and Stability of Human EEG: Comparing a Linear vs a Nonlinear Approach

We have applied the so-called “unfolding dimension approach’’ to reanalyze an earlier longitudinal EEG study. Both linear and nonlinear approaches show that the EEG comprises a static, person-specific part upon which nonstatic and state-specific parts are superimposed. The intraindivi-dual specificity and stability of the genetic part are similar between methods. This is assessed by comparing the outcome of a person to his own outcomes at later times (14 days and 5 years later). The nonlinear method revealed a median correlation coefficient = 0.55, whereas advanced linear methods showed a median = 0.84. An apparent effect for the 5-year interval was detected with the nonlinear method and is discussed in terms of the different assumptions of the two approaches concerning EEG signal generation.

[Community-based crisis home programme. Cost-efficient alternative to psychiatric hospitalization]

BACKGROUND

Over recent decades, institutional psychiatric care has shifted its focus from traditional inpatient treatment to a variety of more advanced outpatient services. Within this context, a new "crisis home" programme (CHP) was launched in Zurich on 1 January 2005. With this programme, mentally ill patients can avoid hospitalization by living with a host family for a certain time period while receiving standard outpatient care. In this study we addressed the question of whether the quite substantial financial advantages of the Zurich CHP over traditional inpatient care are achieved at the expense of a reduced quality of care.

SAMPLE AND METHODS

Between 1 January 2005 and 30 June 2007, a total of 33 patients enrolled in the Zurich CHP with an average stay of 19 days at host families. The vast majority of the patients (85%) were moderately to severely ill at study entry. Of these patients data were collected in a standardized way on the basis of five rating instruments. The statistical data analysis included cross-comparisons with corresponding inpatient data.

RESULTS

Results showed that (1) the CHP works well in a routine setting and provides cost-efficient interventions for patients in acute crises; (2) the financial advantages of the Zurich host family programme over traditional inpatient care do not lead to a reduced quality in patient care; (3) patients suffering from severe mental illnesses clearly benefit from this programme, thus avoiding hospitalization.

CONCLUSIONS

The Zurich CHP is a cost-efficient alternative to traditional inpatient treatment. Specifically, our results suggest that this type of acute crisis intervention should be established as a standard psychiatric care service.

Trait-like individual differences in the human sleep electroencephalogram

We aimed to examine whether commonly observed individual differences in sleep architecture and the sleep electroencephalogram reflect individual traits, which are amenable to a genetic investigation of human sleep. We studied intra-individual stability and inter-individual variation in sleep and sleep electroencephalogram spectra across four baseline recordings of eight healthy young men. A similarity concept based on Euclidean distances between vectors was applied. Visually scored sleep variables served as feature vector components, along with electroencephalogram power spectra in non-rapid-eye-movement and rapid-eye-movement sleep. The distributions of similarity coefficients of feature vectors revealed a clear distinction between high within-subject similarity (i.e. stability), and low between-subject similarity (i.e. variation). Moreover, a cluster analysis based on electroencephalogram spectra in both non-rapid-eye-movement and rapid-eye-movement sleep segregated all four baseline nights of each individual into a distinct cluster. To investigate whether high and low sleep pressure affects the similarity coefficients, normalized non-rapid-eye-movement sleep electroencephalogram spectra of the first and second half of the recordings were compared. Because the electroencephalogram changes systematically in the course of the night, within-subject variation no longer differed from between-subject variation. In conclusion, our data provide evidence for trait-like characteristics in the sleep electroencephalogram. Further studies may help to identify distinct phenotypes to search for genes underlying functional aspects of undisturbed human sleep.

A genome-wide screen on the genetics of atopy in a multiethnic European population reveals a major atopy locus on chromosome 3q21.3

BACKGROUND

Dissecting complex diseases in underlying distinct traits and studying these for their genetic basis might enhance the power as well as the specificity, of detection of disease genes. These phenotypes are known as intermediate phenotypes.

OBJECTIVE

We were interested in the atopic basis of asthma, and used the sensitization to mite (Dermatophagoides pteronyssinus) allergens as a pathophysiologically important intermediate phenotype.

METHODS

This time we performed a genome-wide scan based on the same already used multiethnic European population consisting of 82 nuclear families with at least two affected siblings. We carried out nonparametric as well as parametric MOD-score analyses based on the genotypes of 603 microsatellite markers.

RESULTS

In comparison with our first genome-wide candidate region search three novel regions additionally appeared to be significant. We obtained significant results for the region 2p12 with a MOD score of 3.35 and for the region 16q21 with a MOD score of 4.18. The most significant result was found for the region 3q21.3 with the same microsatellite marker, which showed significant linkage to atopic dermatitis (AD) in another study with a MOD score of 4.51 and an nonparametric linkage analysis (NPL) of 4.00.

CONCLUSION

Our findings indicate that atopy, allergic asthma, allergic rhinitis and AD on the one hand are distinct traits on both the clinical and genetic basis, but on the other hand, our results also underline that these traits are closely related diseases concerning the atopic basis of the traits.

The catechol-O-methyltransferase Val108/158Met polymorphism affects short-term treatment response to mirtazapine, but not to paroxetine in major depression

The catechol-O-methyltransferase (COMT) is a major degrading enzyme in the metabolic pathways of catecholaminergic neurotransmitters such as dopamine and norepinephrine. This study investigated whether the functionally relevant Val(108/158)Met gene variant is associated with differential antidepressant response to mirtazapine and/or paroxetine in 102 patients with major depression (DSM-IV criteria) participating in a randomized clinical trial with both drugs. In patients treated with mirtazapine, but not paroxetine, allelic variations in the COMT gene were associated with differential response. COMT(VAL/VAL) and COMT(VAL/MET) genotype carriers showed a better response than COMT(MET/MET)-bearing patients in the mirtazapine group. Moreover, carriers of the COMT(VAL/VAL) or COMT(VAL/MET) genotype had significantly greater HAMD-17 (Hamilton Rating Scale for Depression 17 item version) score reductions than COMT(MET/MET) homozygotes from week 2 to 6, respectively, in the mirtazapine group. Time course of response and antidepressant efficacy of mirtazapine, but not paroxetine, seem to be influenced in a clinically relevant manner by this allelic variation within the COMT gene.

Nongenetic pathologic developments of brain-wave patterns in monozygotic twins discordant and concordant for schizophrenia

Evidence from previous studies has suggested that the inter-individual differences in human brain-wave patterns (EEG) are predominantly determined by genetic factors. In particular, the within-pair EEG concordance of monozygotic (mz) twins was found to be typically as high as r = 0.81 across channels and frequency bands, thus being comparable to that between repeated assessments on the same individual with typically r = 0.83. Yet our investigations into mz twins discordant and concordant for schizophrenia yielded a significantly reduced within-pair EEG concordance for both, the pairs discordant for schizophrenia and the pairs concordant for schizophrenia (with concordance for schizophrenia assessed through a syndrome-oriented approach). A multivariate discriminant function of EEG parameters distinguished in a reproducible way between affected and unaffected subjects at an overall performance of >75% correctly classified subjects, while the severity of illness, as derived from EEG-differences between affected and unaffected subjects, was closely related to the severity of illness as provided by psychopathology syndrome scores. Consequently, EEG anomalies associated with schizophrenia and manifested differently in the mz co-twins concordant for schizophrenia are likely the effect of nongenetic, pathologic processes that evolved independently in the co-twins' genetically identical brains once the illness began to progress. The existence of such nongenetic processes would suggest a modification of the standard phenotype-to-genotype search strategies of molecular-genetic studies that aim to link the schizophrenia phenotype to genetic vulnerability factors.

Ethnicity-independent genetic basis of functional psychoses: a genotype-to-phenotype approach

The functional psychoses schizophrenia, schizoaffective disorder, and bipolar illness represent complex clinical syndromes that are characterized by phenotypic heterogeneity. Yet evidence from numerous studies suggests that (1) the prevalence of schizophrenia and bipolar illness is with 1% very similar across ethnicities, and (2) a strong genetic component is involved in the disorders' pathogenesis. Using data from different US-American ethnicities (77 families with a total of 17 unaffected and 170 affected sib pairs; 276 marker loci), we searched for ethnicity-independent oligogenic susceptibility loci for which the between-sib genetic similarity in affected sib pairs deviated from the expected values. Specifically, we addressed the question of the extent to which genetic risk factors and their interactions constitute multigenic inheritance of functional psychoses across populations and might constitute universal targets for treatment. Our novel multivariate genotype-to-phenotype search strategy was based on a genetic similarity function that allowed us to quantify the inter-individual genetic distances d(x(i), x(j)) between the allelic genotype patterns x(i), x(j) of any two subjects i, j with respect to n loci l(1), l(2), em leader l(n). Thus, we were able to assess the between-ethnicity, the within-ethnicity, and the within-family genetic similarities. The problem of ethnicity-independent vulnerability was addressed by treating the Afro-American families as "training" samples, while the non-Afro-American families served as independent "test" samples. We evaluated the between-sib similarities, which were expected to deviate from "0.5" in affected sib pairs if the region of interest contained markers close to vulnerability genes. The reference value "0.5" was derived from the parent-offspring similarities that are always 0.5, irrespective of the affection status of parents and offspring. We found 12 vulnerability loci on chromosomes 1, 4, 5, 6, 13, 14, 18, and 20, that were reproducible across the two samples under comparison and therefore, likely to constitute an ethnicity-independent, oligogenic vulnerability model of functional psychoses. The elevated vulnerability appeared to be unspecific and to act in such a way that exogenous factors become more likely to trigger the onset of psychiatric illnesses.

Selecting methodologies for the evaluation of differences in time to response between antidepressants

BACKGROUND

The delay in the therapeutic effect of antidepressants is a considerable impediment to their successful clinical use, and attention has recently been focused on antidepressant drugs that may have a faster onset of action.

DATA SYNTHESIS

Several methodologies exist for evaluating differences in time to response between antidepressants including the identification of the timepoint at which statistically or clinically significant differences between treatment groups emerge, pattern analysis, and survival analytical approaches. All have conceptual as well as practical advantages and disadvantages.

CONCLUSION

The survival analytical approach is generally considered to be the most rigorous and sensitive in detecting differences in the speed of response of antidepressants, but the other methodologies provide useful information.

Linguistic analysis of the speech output of schizophrenic, bipolar, and depressive patients

Using speech samples of 100 patients suffering from schizophrenia, bipolar illness and major depression, we addressed the question of the extent to which the linguistic abnormalities in the speech of these patients represent diagnosis-specific characteristics or constitute independent, syndrome-like dimensions of the illnesses. All speech samples were transcribed by a professional linguist who was blind to both identity and diagnosis of the patients. The majority of the deviant linguistic variables was found to be common to all three diagnostic groups under comparison, while only a few linguistic variables exhibited statistically significant between-group differences. On the other hand, when the respective variables were analysed as a multivariate entity, the variety of subtle between-group differences allowed us to discriminate between the diagnostic groups at an overall performance of 72.7% correctly classified patients. There was an almost complete lack of association between linguistic abnormalities and psychopathology syndromes. In particular, we found no correlation between the syndrome 'formal thought disorder' and the large variety of linguistic variables used in this investigation. In consequence, we conjecture that linguistically deviant speech characteristics represent an independent syndrome complex manifested at varying intensities across mental illnesses, and that this syndrome complex deserves greater attention, not only with respect to the principal understanding of the underlying disturbances, but also as a potential target of therapeutical intervention.

Oligogenic approaches to the predisposition of asthma in ethnically diverse populations

Using the genome-wide screening data of the Collaborative Study on the Genetics of Asthma (CSGA) (226 families, 1,461 genotyped subjects, 323 marker loci) and Hutterite studies (129 families, 690 genotyped subjects, 365 marker loci), we applied a genetic similarity function in order to quantify the inter-individual genetic distances d(xi,xj) between feature vectors xi, xj made up by the allelic patterns of subjects i,j with respect to loci li, l2,..., ln. Based on this similarity function, we structurally decomposed the genetic diversity of the CSGA population in order to address the question of ethnicity-related asthma vulnerability for genetically homogenous CSGA subgroups. The question of ethnicity-independent asthma vulnerability was investigated with all CSGA families as training and the Hutterite families as replication samples. We evaluated the between-sib similarities, which were expected to deviate from "0.5" in affected sib pairs if the region of interest contained markers close to disease-causing genes. The reference value 0.5 was derived by determining the parent-offspring similarities, which are always 0.5, irrespective of the affection status of parents and offspring. We found 18 vulnerability loci on chromosomes 1, 3, 4, 5, 6, 8, 12, 13, and 14, which were remarkably reproducible in the CSGA and the Hutterite data and constituted an ethnicity-independent oligogenic model.

Mortality of patients with mood disorders: follow-up over 34-38 years

BACKGROUND

All follow-up studies of causes of death in affective disordered patients have found they have markedly elevated suicide rates and a less reproducible increased mortality from other causes. The reported rates by gender, disorder type and treatment are more variable.

METHODS

Hospitalised affective disordered patients (n=406) were followed prospectively for 22 years or more. Later, mortality was assessed for 99% of them at which time 76% had died.

RESULTS

Standardised Mortality Rates (observed deaths/expected deaths) for patients were elevated especially for suicide and circulatory disorders in both men and women. Women actually had higher suicide rates but that did not take into account the twofold increase in general population rates for men. Unipolar patients had significantly higher rates of suicide than bipolar Is or IIs. In all groups long term medication treatment with antidepressants alone or with a neuroleptic, or with lithium in combination with antidepressants and/or neuroleptics significantly lowered suicide rates even though the treated were more severely ill. Although at the age of onset the suicide rates were most elevated, from ages 30 to 70 the rates were remarkably constant despite the different courses of illness.

LIMITATIONS

The patients were identified as inpatients and followed prospectively. The treatments were uncontrolled and are not quantifiable but were documented during the follow-up.

CONCLUSIONS

Men and women hospitalised for affective disorders have elevated mortality rates from suicide and circulatory disorders. Unipolars have higher suicide rates than bipolar Is or IIs. Long term medication treatment lowers the suicide rates, despite the fact that it was the more severely ill who were treated.

Schizophrenia and smoking: evidence for a common neurobiological basis?

Several previous investigations have suggested that the gene for the alpha 7-nicotinic receptor may play a role in the pathogenesis of schizophrenia and may be responsible for the heavy smoking among schizophrenic patients. In a study of 129 healthy controls and 127 schizophrenic, schizoaffective, and bipolar patients we have aimed 1) to confirm the potential association between schizophrenia and the alpha 7-nicotinic receptor, 2) to test the diagnostic specificity of alpha 7-receptor subunits with respect to psychiatric diagnoses, and 3) to investigate potential receptor differences between smokers and nonsmokers in the general population. Our analysis included the two dinucleotide polymorphisms D15S1360 and L76630 that are localized in a genomic fragment containing the alpha 7-nicotinic receptor gene CHRNA7. Highly significant differences (P < 0.0001) between the allele distributions of patients and controls were detected for these two markers with all three diagnostic subgroups contributing to the discrimination. An independently ascertained replication sample of 24 patients confirmed this finding. Our results suggested an unspecific vulnerability that depended on the severity of overall psychopathology in terms of the co-occurrence of psychopathology with no clear-cut boundary between the diagnostic entities. In comparison with healthy controls, this vulnerability was lowest among schizophrenics, intermediate among bipolars, and highest among schizoaffectives. As to the question of alpha 7-receptor differences between smokers and nonsmokers among the healthy control subjects, our analysis revealed no significant differences, thus indicating that the differences between patients and controls are more than just a smoker/nonsmoker distinction. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:173-177, 2000.

Intraindividual specificity and stability of human EEG: comparing a linear vs a nonlinear approach

We have applied the so-called "unfolding dimension approach" to reanalyze an earlier longitudinal EEG study. Both linear and nonlinear approaches show that the EEG comprises a static, person-specific part upon which nonstatic and state-specific parts are superimposed. The intraindividual specificity and stability of the genetic part are similar between methods. This is assessed by comparing the outcome of a person to his own outcomes at later times (14 days and 5 years later). The nonlinear method revealed a median correlation coefficient rho = 0.55, whereas advanced linear methods showed a median rho = 0.84. An apparent effect for the 5-year interval was detected with the nonlinear method and is discussed in terms of the different assumptions of the two approaches concerning EEG signal generation.

Integration of genetic maps by polynomial transformations

Currently available genetic maps differ in a variety of basic features; in particular, with respect to the total length of the genome. Consequently, the question arises as to the extent to which genetic maps are compatible to each other, as well as to the methods with which genetic maps can be transformed into one another. We propose a set of nonlinear, polynomial transformations that enable the integration of genetic maps at a sufficiently high overall precision. Our analysis of six major, publicly available maps, and iteratively optimized polynomials of up to degree 5, yielded differences of </= +/-0.8 cM between empirical and reconstructed marker locations for >90% of points. Similarly, we determined, at a slightly worse overall fit, those polynomials that enabled the reconstruction of sex-specific recombination estimates from sex-averaged data. Our results suggest that polynominal transformations may become a valuable extension of standard map construction methods due to a rapid integration of newly developed markers into existing maps. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:108-113, 2000.

Structural decomposition of genetic diversity in families with alcoholism

Using genotypes of 280 marker loci on the 22 autosomes of 105 alcohol-dependent probands, their affected and unaffected sibs, as well as their parents, we iteratively constructed a genetic similarity function that enabled us to quantify the interindividual genetic distances d(x(i), xj) between feature vectors x(i), xj made up by the allelic patterns of individuals i, j with respect to loci l1, l2,...,ln. Based on this similarity function, we investigated the sib-sib similarities that are expected to deviate from "0.5" in affected sib pairs if the region of interest contains markers close to disease-causing genes. The reference value "0.5" was derived from the parents-offspring similarities, because these are independent of the affection status. The question of population admixture was addressed by means of multivariate structural analyses. These analyses led to four "natural" groups whose validity was tested through the father-mother similarities. Additionally, we determined the eigenvectors that optimally represented the genetic variation and found several marker configurations on chromosomes 1, 3, 7, 15, and 17 that reproducibly discriminated (p < or = 0.01) affected probands/sibs from unaffected sibs, while no such differences were found between affected probands and affected sibs.

Suicide risk in patients with major depressive disorder

Understanding the origins of suicide is the first step in preventing it. Review of the current literature has revealed only limited data from general practice and community samples; most research has been performed on inpatient psychiatric populations, and extended follow-ups are rare. Mood disorders were found to be highly associated with suicide, especially in patients with major depressive disorder. Depression is an important factor in suicides of adolescents and the elderly, but those with late-onset depression are at higher risk. Both comorbidity with other disorders, such as anxiety and agitation, and rapid changes in the depressive state, for instance after release from the hospital, increase the risk for suicide.

Fluoxetine versus moclobemide: cross-comparison between the time courses of improvement

Competitive statistical methods were used in a meta-analysis of the data of 440 fluoxetine-treated and 437 moclobemide-treated patients in order to address the issue of the timing of recovery from depression, and to elucidate potential differences in the onset of action between the two different classes of antidepressants. In spite of large biochemical and pharmacological differences, fluoxetine and moclobemide turned out to be virtually identical with regard to the overall efficacy, proportions and time characteristics of premature withdrawal, and most notably, the time course of recovery. The onset of improvement occurred in the majority of cases within the first two weeks of treatment and was highly predictive for the outcome after six weeks. The analyses yielded no indication of a delayed onset of action of antidepressants. Given the apparent nonspecificity of antidepressants, together with their relatively modest response rates, future research will need consider whether mechanisms different from those related to the monoaminergic systems may be involved in the pathogenesis of depression.

EEG differences in monozygotic twins discordant and concordant for schizophrenia

In an electroencephalographic (EEG) study of 27 pairs of monozygotic (MZ) twins discordant for schizophrenia, 13 pairs of MZ twins concordant for schizophrenia, 40 pairs of healthy MZ twins, and 91 healthy, unrelated subjects with repeated assessments, we investigated (a) the trait quality of brainwave patterns with respect to interindividual differences, intraindividual stability over time, and within-pair MZ concordance; (b) the EEG characteristics that enable discrimination between affected and unaffected individuals; and (c) the EEG characteristics that reflect the severity of illness. In comparison with healthy control subjects, the MZ twins who were discordant and concordant for schizophrenia exhibited a much lower within-pair EEG concordance, so that EEG abnormalities associated with schizophrenia and manifested differently in the co-twins concordant for schizophrenia seemed to reflect nongenetic, pathological developments of genetically identical brains.

The speech analysis approach to determining onset of improvement under antidepressants

In a study of 43 hospitalized depressive patients we investigated the course of recovery at a dense time resolution throughout the first two weeks of treatment. In addition to the assessment of the patients' psychopathology on the basis of HAMD and AMDP rating scales, speech recordings were carried out for each patient immediately before the psychiatric exploration. Our analyses yielded no evidence for a delayed onset of action of antidepressants. Onset of improvement occurred in the great majority of patients (79.1%) within the first 12 days of study, independently of the severity of depression at baseline. Early improvement was highly predictive of later outcome and could not be attributed to a few items, as score reductions were observed for virtually all HAMD items at very early stages of recovery. The analysis of the patients' speaking behavior and voice sound characteristics yielded in 62.8% of cases an essentially parallel development over time for the HAMD scores on the one hand, and acoustic variables on the other. In consequence, early improvement appears to have a biological background and is unlikely to be mainly attributable to the expectations of doctors and patients.

Familial brain wave patterns: study of a 12-sib family

In the sense of a paradigm for the heritability of complex psychiatric disorders, we compared the brain wave patterns of a 12-sib family with those of 144 unrelated controls and with those of 14 pairs of monozygotic twins. Under constant experimental conditions, electroencephalogram (EEG) parameters generally displayed a broad range of inter-individual differences, but were also remarkably stable over time within each subject, thus suggesting that the variation of EEG parameters forms a continuous phenotypic range rather than discrete phenotype classes. The distributions of all EEG parameters were found to be unimodal but significantly different from a normal distribution. Although an unimodal distribution speaks in favor of a polygenic additive mode of inheritance, this may not necessarily be true. Our findings might reflect the fact that a symmetric environmental distribution is converted through the underlying genotypes' norm of reaction into an asymmetric phenotype distribution. On the other hand, the distributions of the power-related EEG parameters were not that clearly unimodal, and with a larger sample size a trimodal solution might have become significant. With respect to the between-sib EEG similarity, we found the empirically derived value to be approximately half that of the within-subject similarity at 14-day intervals and of the within-pair similarity of monozygotic twins. This finding confirmed earlier results on monozygotic twins brought up together and reared apart, concerning the estimated value of h2. All in all, the EEG paradigm has clearly demonstrated that the methods of quantitative genetics represent a powerful tool once phenotypes designed to assess the variation of a trait are based on dimensional quantities.

Speaking behavior and speech sound characteristics in acute schizophrenia

Based on a sample of 45 hospitalized, acute-schizophrenic patients and 45 carefully matched controls, we investigated the non-verbal characteristics of schizophrenic speech by means of an 'acoustic' speech analysis and determined the extent to which speaking behavior and speech sound characteristics had adjusted toward normal values at the time of hospital release. Using a multivariate discriminant function derived from a previous study of chronic schizophrenics, totally 77 (85.6%) individuals of our patient and control sample could be correctly classified by a set of 12 acoustic variables at entry into study. At hospital release, the majority of patients (64.4%) still exhibited speech impairment although acute psychopathology had significantly improved. A configuration of 6 acoustic variables, assessed at the time point of entry into study, predicted at high reliability the severity of the negative syndrome at hospital release. Acute medication effects did not explain these findings, thus underlining the potential diagnostic relevance of the speech analysis method. With respect to the relationship between speech characteristics and acute psychopathology throughout the time course of recovery, our results suggest that changes in speaking behavior and speech sound characteristics may be distinct aspects of schizophrenia that can persist in a subgroup of patients over a long period, mostly beyond the time point of hospital release. Accordingly, the speech analysis method might become very useful in detailing the nature and severity of deficits in patients after remission of positive symptoms.

Age-of-onset or age-cohort changes in the lifetime occurrence of depression?

In a re-investigation of the NIMH Psychobiology of Depression data, we have studied the question of shifts towards earlier onset together with the question of steadily increasing lifetime risk of major depression in successive birth-cohorts. Using a contingency-table approach, it turned out that inhomogeneities with respect to successive birth-cohorts exclusively showed up in the neighborhood of principally unobservable combinations of the variables under investigation. Standard approaches to testing independence in cross-classified data, such as the quasi-independence model, yielded highly significant results. Through the definition of a log-linear model with weights which replaces the 'discrete' truncation of the quasi-independence approach by a 'smoothed' truncation, it was possible to fully explain the observed age-of-onset shifts, thus supporting the hypothesis that age-of-onset and birth-cohort are independent. With respect to the question of generational changes in the lifetime risk of depression this independence implied that such changes should occur at equal rates across all ages of onset. The analysis yielded significantly larger cohort sizes for the two youngest birth-cohorts, a fact which might be interpreted as an indication of increasing environmental impacts on the genetically predisposed vulnerability during recent years. However, our cross-sectional survey data were, by design, not an optimal basis for a reliable assessment of changes in the lifetime risk of depression, because the risk estimate derived from affected-only survey data corresponds to the probability that a depressive belongs to a certain birth-cohort and is only loosely related to the lifetime risk of this cohort (which is the probability that a person belonging to a certain birth-cohort develops depression). We therefore conclude, firstly, that method effects are likely to explain a major portion of secular trends thus far reported in the literature, and, secondly, that there appears to be no clear necessity to include changing environmental effects into quantitative genetic modelling.

Delayed onset of action of antidepressant drugs? Survey of results of Zurich meta-analyses

The onset of action of antidepressant drugs was investigated on the basis of two independent, multicenter, double-blind studies, comparing amitriptyline (N = 120), oxaprotiline (N = 120), imipramine (N = 506) and moclobemide (N = 580) with placebo (N = 189/+191). Highly significant differences between the active drugs and placebo were found with respect to the total number of improvers and the total number of responders. In addition, significant differences between treatment modalities showed up in both the percentage rate and the time distribution of premature withdrawals. However, among improvers, the distribution of time spans to onset of improvement was found to be independent of treatment modality, indicated by virtually identical cumulative percentages of improvers over the whole observation period. This picture of treatment-independent improvement rates was essentially the same for the HAMD, HAMA and ZUNG assessments, except for a significant time lag between observerratings and self-ratings. Specifically, our analyses revealed no evidence for a delayed onset of action of various antidepressants with large biochemical and pharmacological differences when compared to placebo. The early onset of improvement was highly predictive of later outcome: on average, 70% of patients showing improvement within the first 14 days became responders. Differences between active treatments and placebo emerged within the first five days and reached a point of maximum distinction around day 14. After this time point, differences between treatment modalities remained constant until the end of the observation period. Not more than 20-25% of patients were, on average, "true" drug responders, thus suggesting that the therapeutic qualities of antidepressants do not lie in the suppression of symptoms, but rather relate to their ability to elicit and maintain certain conditions which enable recovery in a subgroup of patients who would otherwise remain nonresponders.

Reliable computer-assisted classification of the EEG: EEG variants in index cases and their first degree relatives

A method which optimizes on global properties of sample recordings is proposed for the definition of and the discrimination between electroencephalogram (EEG) classes. The sample was drawn from students at the University of Heidelberg from 1974 to 1978 and consists of 15 healthy index cases clinically ascertained as belonging to the low voltage EEG group. In addition, the three clinically defined groups: diffuse beta (18 index cases), borderline alpha (12 index cases) and monomorphous alpha (18 index cases) have been included in the study, as well as the first degree relatives of the index cases, thus providing a clinical classification into four groups. The proposed method provides an automatic and reliable classification algorithm using discriminant and cluster analysis. The relation between such an automatized classification and clinical classification schemes is investigated. In particular, the inheritance of the low voltage EEG, the question on sex differences and the question of a simple Mendelian mechanism had been examined. The method of random splittings had been applied for discriminant and cluster analysis. Our findings can be summarized as follows: (1) except for the monomorphous alpha EEG group, the clinical classification shows rather marginal separation (discriminating performance 60% to 75%), while a new and more reliable grouping scheme improves the discriminating performance up to 87% to 91%. The latter scheme leads to the concept of personal channel pattern (PCP) and was compared to the clinical classification scheme by means of contingency tables; (2) only a weak correlation between the clinically and PCP-based groups could be found (Cramér Index: 0.27). Accordingly, we continued to investigate the extent to which the proposed EEG classification scheme can nevertheless explain the genetic mechanisms apparently involved in the low voltage EEG. We thus considered the role of sex differences manifest in our proposed new grouping scheme; (3) males occurred more frequently in the new group 3 and females more frequently in the new group 1. In this regard, a much better correlation of the new groups between mothers and children than between fathers and children was observed; and (4) with help of our new PCP scheme, we have been able to reproduce a simple two gene Mendelian scheme to explain inheritance of the clinical low voltage EEG group. In this PCP-based scheme, the low voltage property does not occur when dominance of a certain gene (called gene A) is absent.

Speaking behavior and voice sound characteristics associated with negative schizophrenia

Based on a sample of 42 chronic schizophrenic patients and 42 carefully matched controls, we investigated potential relationships between acoustic variables on the one hand, and negative syndromes, positive syndromes and affective disturbances, on the other. A set of 12 acoustic variables automatically assessed in a standardized experimental setting allowed an almost perfect discrimination between schizophrenic patients and normal subjects. Acute side-effects of medication did not explain this finding. However, the question of whether the observed changes in speaking behavior and voice sound characteristics were caused by long-term neuroleptic treatment, for example, as a consequence of tardive dyskinesia, could not be answered by our investigation. In view of a biological validation of the negative-positive model of schizophrenia, the reliability of various psychopathological subscales was tested through repeated assessments at 14 day intervals. We found most psychopathology scores to be sufficiently stable and reproducible over time, thus representing a suitable basis for the estimation of severity with respect to the negative and positive component of schizophrenia. Using the first measurements as training samples and the second measurements of 14 days later as test samples, discriminant analysis yielded conclusive proof of a close relationship between acoustic variables and the severity of the negative and positive component of schizophrenia. In particular, by means of "objective" acoustic variables and under the constraint of reproducibility, 75.9% of patients were correctly classified as low or high scorers with respect to the negative syndrome, 71.9% of patients with respect to the positive syndrome, and 79.4% of patients with respect to their depressive symptomatology.

Cognitive performance in patients recovering from depression

Investigations into the development of cognitive impairment in 30 hospitalized depressive patients have suggested that such disturbances encompass two dichotomous entities: a core entity of long-persisting, therapy-resistant impairment and an entity of reversible impairment with a prompt onset of improvement. The course of improvement turned out to evolve largely independently with respect to psychopathology: about one half of patients displayed severe cognitive dysfunctions which remained virtually unchanged until hospital discharge, while 80% significantly improved within the first 12 days with respect to their depressive symptoms, and 53.3% displayed a clear response to treatment at the time of hospital discharge. In particular, a considerable number of patients with a significant reduction of depressive symptomatology at hospital discharge still suffered from severe cognitive dysfunctions. Neither antidepressant or antipsychotic medication nor acute side effects due to medication explained the development of cognitive impairment. Accordingly, cognitive impairment seems to represent an essentially independent syndrome complex comparable to 'deficits' or 'negative symptoms' in schizophrenia. On the other hand, single case correlation analysis revealed a somewhat closer relationship of cognitive impairment with speech behavior and voice sound characteristics. Two thirds of patients displayed significant correlations between cognitive performance scores and second-order constructs like speech flow, dynamics or intonation. However, the respective subgroups defined by significant correlations with single speech parameters were relatively small (< or = 35% of cases), thus indicating that there exist large interindividual differences as to how cognitive impairment affects the patients' speech.

Speaking behavior and voice sound characteristics in depressive patients during recovery

Based on a sample of 30 depressive patients, we have investigated the time course of recovery from depression in so far as this time course was assessable through changes in psychopathology syndrome scores and through changes in speaking behavior and voice sound characteristics. Specifically, our study design provided 6 repeated assessments over 2 weeks and at a fixed time in the morning each Monday, Wednesday and Friday, plus a final assessment at the patients' releases from hospital. Thus, we were able to determine the degree to which single-parameter approaches to speaking behavior and voice sound characteristics reflect the individual time course of recovery from depression. In this context, we could rely upon a calibration sample with repeated assessments on 192 healthy volunteers which yielded all necessary information concerning reproducibility and sensitivity of speech parameters. Our analysis revealed several prominent features of speaking behavior and voice sound characteristics to be closely related to the time course of recovery from depression. In particular, the parameters "F0-amplitude", "F0-6db-bandwidth" and "F0-contour" which assess important characteristics of a speaker's voice timbre, as well as the parameters "energy" and "dynamics" which assess a speaker's mean loudness and the variation of loudness over time, displayed consistently high correlations with depression syndromes. Moreover, the results of single-case analysis turned out to be in remarkable accordance with those of the cross-sectional one: in almost two-thirds of patients there existed a significant relationship over time between the global depression scores and major speech parameters. As to the remaining one-third of patients who did not fit the picture of high correlations between psychopathology and speech parameters, we found an overproportionally large number of non-improvers characterized by irregular patterns of slight improvement with subsequent deterioration, or of deterioration followed by slight improvement. In other words, one-third of patients displayed time courses of depression whose psychopathology is difficult to assess through standard exploration techniques. Accordingly, it is not clear whether the observed lack of correlation in these patients is due to insufficient data or to an actual discordance between the time development of psychopathology and that of speech parameters.

Time course of improvement under antidepressant treatment: a survival-analytical approach

A meta-analysis of an earlier multicenter, double-blind efficacy study comparing placebo, oxaprotiline and amitriptyline was performed in order to test the survival-analytical approach in modelling the onset of improvement and response to treatment with antidepressants. The sample consisted of moderately depressed male (n = 154) and female (n = 275) patients (aged 17-73), diagnosed according to DSM-III criteria for major depression. Of these, 120 were treated with oxaprotiline, 120 with amitriptyline and 189 with placebo. Efficacy criteria were Hamilton Depression (HAMD) and Anxiety (HAMA) and Zung Self-Rating scales. Up to eight ratings over a period of 40 days were available for analysis. The results showed that the sensitivity in discriminating between groups was substantially enhanced through the inclusion of drop-outs and consideration of the effect of time to withdrawal from the study due to lack of improvement. Withdrawal from the trial due to inefficacy occurred earliest under placebo (50% within the first 8 days), whereas less than 40% dropped out within the first 12 days under active treatments. The most interesting and unexpected finding of the analysis was that the time course of improvement among responders was independent of the treatment modality, and thus identical in all three groups. Specifically, the efficacy of any of the given treatments was reflected only by the total number of responders or nonresponders. Once triggered, the time course of recovery from illness becomes identical to that of spontaneous remissions as observed, for example, under placebo.(ABSTRACT TRUNCATED AT 250 WORDS)

The octave approach to EEG analysis

A "tonal" approach to EEG spectral analysis is presented which is compatible with the concept of physical octaves, thus providing a constant resolution of partial tones over the full frequency range inherent to human brain waves, rather than for equidistant frequency steps in the spectral domain. The specific advantages of the tonal approach, however, mainly pay off in the field of EEG sleep analysis where the interesting information is predominantly located in the lower octaves. In such cases the proposed method reveals a fine structure which displays regular maxima possessing typical properties of "overtones" within the three octaves 1-2 Hz, 2-4 Hz and 4-8 Hz. Accordingly, spectral patterns derived from tonal spectral analyses are particularly suited to measure the fine gradations of mutual differences between individual EEG sleep patterns and will therefore allow a more efficient investigation of the genetically determined proportion of sleep EEGs. On the other hand, we also tested the efficiency of tonal spectral analyses on the basis of our 5-year follow-up data of 30 healthy volunteers. It turned out that 28 persons (93.3%) could be uniquely recognized after five years by means of their EEG spectral patterns. Hence, tonal spectral analysis proved to be a powerful tool also in cases where the main EEG information is typically located in the medium octave 8-16 Hz.

Speech characteristics in depression

This study examined the relationship between speech characteristics and psychopathology throughout the course of affective disturbances. Our sample comprised 20 depressive, hospitalized patients who had been selected according to the following criteria: (1) first admission; (2) long-term patient; (3) early entry into study; (4) late entry into study; (5) low scorer; (6) high scorer, and (7) distinct retarded-depressive symptomatology. Since our principal goal was to model the course of affective disturbances in terms of speech parameters, a total of 6 repeated measurements had been carried out over a 2-week period, including 3 different psychopathological instruments and speech recordings from automatic speech as well as from reading out loud. It turned out that neither applicability nor efficiency of single-parameter models depend in any way on the given, clinically defined subgroups. On the other hand, however, no significant differences between the clinically defined subgroups showed up with regard to basic speech parameters, except for the fact that low scorers seemed to take their time when producing utterances (this in contrast to all other patients who, on the average, had a considerably shorter recording time). As to the relationship between psychopathology and speech parameters over time, we found significant correlations: (1) in 60% of cases between the apathic syndrome and energy/dynamics; (2) in 50% of cases between the retarded-depressive syndrome and energy/dynamics; (3) in 45% of cases between the apathic syndrome and mean vocal pitch, and (4) in 71% of low scores between the somatic-depressive syndrome and time duration of pauses. All in all, single parameter models turned out to cover only specific aspects of the individual courses of affective disturbances, thus speaking against a simple approach which applies in general.

Long-term prognosis of schizophrenia

The question of determining prognostically relevant features for schizophrenia was approached with multivariate statistical methods applied to the data from the Bonn longitudinal study of 502 schizophrenic patients. In this study, personal interviews according to a clinical classification scheme allowed every patient to be ranked within each of three different outcome classes: psychopathological remission, occupational remission, and course type. Our multivariate analysis encompassed a total of 50 items pertinent to the time up to and including the first 6 months after the first psychotic manifestation. Despite the introduction of mathematical methods considerably more sophisticated than those employed in earlier studies, no satisfactory solution could be found to the problem of predicting end states of schizophrenia. Reliable predictions could be made only for 'extreme' end states (i.e. full remission versus (1) characteristic residues in the narrower sense; (2) total unemployment, or (3) surging or simple courses to mixed residues or to typical schizophrenic defect psychoses). Accordingly, sufficiently reliable assertions applied only to a minority of about 1/3 of patients, whereas for the majority of 2/3, no generalizable prognostication was possible (67-71% true-positive predictions on 36-63% of total population in extreme states). By contrast, our analyses have clearly uncovered a fundamental problem of investigations into the long-term prognosis of schizophrenia: the extreme dependence of results on the clinical definition of end states. The further the phenomenon 'end state' is qualitatively subdivided, the poorer and less reproducible is the mutual discrimination between intermediate states and the less reliable are allocations of patients to these intermediate states by means of multivariate classifiers. Furthermore, our analyses have also demonstrated the usefulness of multivariate, adaptive procedures for investigations into the structural properties of long-term courses, so that predictions might be considerably improved if more reliable definitions of schizophrenic end states are available.

Affective state and voice: results of a pilot study with six depressive patients

As part of an investigation into the nonverbal information in human speech, a pilot study with depressive patients was designed in order to model the global affective state as a function of time and in terms of speech parameters. Over a two-week period, six patients were examined six times at two-day intervals under comparable experimental conditions. The psychopathologic status of these patients was assessed during a psychiatric exploration half an hour before the actual examination was carried out. Besides the solution of the baisc methodological problems, a principal goal of this study was to test the ability and cooperation of depressive patients when asked to speak in the laboratory. It turned out that even scalar parameters such as energy and dynamics give insight into the intraindividual variation of global affective state, and that the examination procedure is practicable even it patients are considerably handicapped by their illness.

Effect of neuroleptics on positive and negative symptoms and the deficit state

The concept of negative symptoms tries to operationalize a deficit syndrome observed in schizophrenia, but also in other disorders. The instruments for the measurement developed so far are unclear in their dimensional structure and validity. Further methodological development is needed. A new scale for measuring negative symptoms was derived from the AMDP-system and applied to results of drug trials with clozapine, fluperlapine, and haloperidol. The three drugs were equally effective on negative symptoms of acute and chronic schizophrenics.