Identification of symptomatologic patterns common to major psychoses: proposal for a phenotype definition

"Apples and pears are similar, but still different things." Bipolar disorder and schizophrenia- discrete disorders or just dimensions ?

Starting with the dichotomous view of Kraepelin, schizophrenia and bipolar disorder have traditionally been considered as separate entities. More recent, this taxonomic view of illnesses has been challenged and a continuum psychosis has been postulated based on genetic and neurobiological findings suggestive of a large overlap between disorders. In this paper we will review clinical and experimental data from genetics, morphology, phenomenology and illness progression demonstrating what makes schizophrenia and bipolar disorder different conditions, challenging the idea of the obsolescence of the categorical approach. However, perhaps it is also time to move beyond DSM and search for more refined clinical descriptions that could uncover clinical invariants matching better with molecular data. In the future, computational psychiatry employing artificial intelligence and machine learning might provide us a tool to overcome the gap between clinical descriptions (phenomenology) and neurobiology.

Meta-analysis of the Brief Psychiatric Rating Scale - Expanded (BPRS-E) structure and arguments for a new version

The factor structure of the 24 item BPRS-E was examined to determine the effect of additional items on consensus scales derived primarily from the 18 item BPRS. A meta-analysis (k = 32, n = 10,084) of previous factor analyses of the BPRS-E was conducted using both a co-occurrence similarity matrix and reproduced correlations. Components generally supporting the consensus scales were found suggesting four relatively invariant subscales: Affect (defined by the core items: anxiety, guilt, depression, suicidality), Positive Symptoms (hallucinations, unusual thought content, suspiciousness, grandiosity), Negative Symptoms (blunted affect, emotional withdrawal, motor retardation) and Activation (excitement, motor hyperactivity, elevated mood, distractibility). The additional BPRS-E items primarily contribute directly to a clear Activation dimension which expands and clarifies the traditional 18 item BPRS structure. Though not statistically supported in this meta-analysis, a fifth factor describing disorganization (conceptual disorganization, disorientation, self-neglect, mannerisms-posturing) was present in some analyses and should be considered. The five factor solution including a disorganization factor has theoretical validity based on the pentagonal model of schizophrenia while also containing the same four primary dimensions that were statistically supported in this meta-analysis. A new version of the BPRS (BPRS-26) with modified and additional items is presented. BPRS-26 is supposed to enhance the stability and the comprehensiveness of the scale and to more closely measure this five factor model.

Clinical and molecular genetics of psychotic depression

This review provides a comprehensive overview of clinical and molecular genetic as well as pharmacogenetic studies regarding the clinical phenotype of "psychotic depression." Results are discussed with regard to the long-standing debate on categorical vs dimensional disease models of affective and psychotic disorders on a continuum from unipolar depression over bipolar disorder and schizoaffective disorder to schizophrenia. Clinical genetic studies suggest a familial aggregation and a considerable heritability (39%) of psychotic depression partly shared with schizoaffective disorder, schizophrenia, and affective disorders. Molecular genetic studies point to potential risk loci of psychotic depression shared with schizoaffective disorder (1q42, 22q11, 19p13), depression, bipolar disorder, and schizophrenia (6p, 8p22, 10p13-12, 10p14, 13q13-14, 13q32, 18p, 22q11-13) and several vulnerability genes possibly contributing to an increased risk of psychotic symptoms in depression (eg, BDNF, DBH, DTNBP1, DRD2, DRD4, GSK-3beta, MAO-A). Pharmacogenetic studies implicate 5-HTT, TPH1, and DTNBP1 gene variation in the mediation of antidepressant treatment response in psychotic depression. Genetic factors are suggested to contribute to the disease risk of psychotic depression in partial overlap with disorders along the affective-psychotic spectrum. Thus, genetic research focusing on psychotic depression might inspire a more dimensional, neurobiologically and symptom-oriented taxonomy of affective and psychotic disorders challenging the dichotomous Kraepelinian view. Additionally, pharmacogenetic studies might aid in the development of a more personalized treatment of psychotic depression with an individually tailored antidepressive/antipsychotic pharmacotherapy according to genotype.

Harnessing clinical psychiatric data with an electronic assessment tool (OPCRIT+): the utility of symptom dimensions

Progress in personalised psychiatry is dependent on researchers having access to systematic and accurately acquired symptom data across clinical diagnoses. We have developed a structured psychiatric assessment tool, OPCRIT+, that is being introduced into the electronic medical records system of the South London and Maudsley NHS Foundation Trust which can help to achieve this. In this report we examine the utility of the symptom data being collected with the tool. Cross-sectional mental state data from a mixed-diagnostic cohort of 876 inpatients was subjected to a principal components analysis (PCA). Six components, explaining 46% of the variance in recorded symptoms, were extracted. The components represented dimensions of mania, depression, positive symptoms, anxiety, negative symptoms and disorganization. As indicated by component scores, different clinical diagnoses demonstrated distinct symptom profiles characterized by wide-ranging levels of severity. When comparing the predictive value of symptoms against diagnosis for a variety of clinical outcome measures (e.g. ‘Overactive, aggressive behaviour’), symptoms proved superior in five instances (R² range: 0.06–0.28) whereas diagnosis was best just once (R²∶0.25). This report demonstrates that symptom data being routinely gathered in an NHS trust, when documented on the appropriate tool, have considerable potential for onward use in a variety of clinical and research applications via representation as dimensions of psychopathology.

Categorical vs dimensional classifications of psychotic disorders

OBJECTIVE

Both categorical and dimensional methods appear relevant to classifying psychotic disorders; however, there is no clear consensus on the most appropriate categories and dimensions or on the best approach for constructing nosologic criteria that integrate these 2 methods. This review examines the evidence on specific dimensions and categories that would best characterize psychoses.

METHOD

Entries in the MEDLINE database between 1980 and 2011 were searched for studies of the dimensional and/or categorical structure of psychosis. Studies were included if samples represented a spectrum of psychotic disorders and dimensions/categories were empirically derived using principal components analysis, factor analysis, or latent class analysis.

RESULTS

Most dimensional studies observed 4 or 5 dimensions within psychosis, with positive, negative, disorganization, and affective symptom domains most frequently reported. Substance abuse, anxiety, early onset/developmental, insight, cognition, hostility, and behavioral/social disturbance dimensions appeared in some studies. Categorical studies suggested 3 to 7 major classes within psychosis, including a class similar to Kraepelin's dementia praecox and one or more classes with significant mood components. Only 2 studies compared the relative fit of empirically derived dimensions and categories within the same data set, and each had significant limitations.

CONCLUSION

There is relatively consistent evidence on appropriate categories and dimensions for characterizing psychoses. However, the lack of studies directly comparing or combining these approaches provides insufficient evidence for definitive conclusions about their relative merits and integration. The authors provide specific recommendations for designing future studies to identify valid dimensions and/or categories of the psychoses and investigate hybrid approaches to model the structure of the underlying illnesses.

Conceptualization of the liability for schizophrenia: clinical implications

Historically, the Diagnostic and Statistical Manual of Mental Disorders (DSM) diagnostic criteria for schizophrenia have emphasized several features, including symptoms of psychosis, a dissociation of symptoms from their etiology, a reliance on clinical symptoms, and a categorical approach to classifying the disorder. Although these emphases are quite useful, they have limitations. We review these here, and stress the importance of incorporating recent data on the genetic /biological and neurodevelopmental origins of schizophrenia into current conceptions of the disorder. We also review “schizotaxia, ” which is a concept thai embodies this point of view, occurs before the onset of psychosis, and is hypothesized to represent the liability for schizophrenia. If our hypothesis on this point is correct, the identification of schizotaxic individuals will eventually facilitate the development of prevention strategies by identifying a premorbid (but clinically significant) condition for schizophrenia. Moreover, the identification of biological or neuropsychological components of schizotaxia will provide more specific bases for developing novel treatment interventions. Our initial attempts to develop protocols for the assessment and treatment of schizotaxia are encouraging, and will be reviewed.

Investigation of shared genetic effects for psychotic and obsessive symptoms in young adult twins

Genetic and environmental architecture of psychotic and obsessive symptoms are not completely elucidated. This study estimated for these symptoms (i) the genetic and environmental components, (ii) the within-individual association, and (iii) the extent to which this association originates from common genetic and environmental factors. Young adult twins (N=701) from the population-based Italian Twin Register were assessed for psychotic and obsessive-compulsive symptoms by using the Symptom Check List (SCL-90). Multivariate Cholesky models were fitted by the Mx statistical program. No previous study used this design to examine the same dimensions. The best-fitting model included additive genetic and nonshared environmental components, each accounting for about half of total variance in the symptoms. Genetic influences on the different symptoms overlapped considerably (r(g)=0.81 to 0.99). Phenotypic correlations of psychotic symptoms and of psychotic with obsessive symptoms were high (r=0.61 to 0.76), with 53% to 69% explained by shared genetic effects. This study shows substantial genetic influence on psychotic and obsessive symptoms, and indicates that their co-occurrence may be due to genetic factors to a greater extent than to environmental effects. These results encourage the search for genetic and environmental factors underlying the covariance between different psychotic traits as well as between psychotic and obsessive traits.

Heritability of age of onset of psychosis in schizophrenia

Schizophrenia is a genetically complex illness with heterogeneous clinical presentation, including variable age of onset. In this study, the heritability, or proportion of variation in age of onset of psychotic symptoms due to genetic factors, was estimated using a maximum likelihood method. The subjects were 717 members of families with more than one member affected with schizophrenia from Mexican and Central American populations. Age of onset of psychosis was determined by best-estimate consensus diagnosis based on the Diagnostic Interview for Genetic Studies, Family Interview for Genetic Studies, and each subject's medical records. Mean age of onset was 21.44 years (SD 8.07); 20.55 years for males (SD 6.90), and 22.67 for females (SD 9.34). Variance components were estimated using a polygenic model in the SOLAR software package. The sex of the participant was a significant covariate (P = 0.010) accounting for 0.02 of the total variance in age of onset. The heritability of age of onset of psychosis was 0.33 (SE = 0.09; P = 0.00004). These findings suggest that genetic factors significantly contribute to the age of onset of psychotic symptoms in individuals with schizophrenia and that sex influences this trait as well.

Psychopathology factors in first-episode affective and non-affective psychotic disorders

BACKGROUND

Since the onset, prevalence, and course of specific psychopathological features rarely have been analyzed simultaneously from the start of dissimilar psychotic illnesses, we compared symptom-clusters in first-episode DSM-IV affective and non-affective psychotic disorders.

METHODS

Subjects (N=377) from the McLean-Harvard First Episode Project hospitalized for first-lifetime primary psychotic illnesses were followed prospectively for 2 years to verify stable DSM-IV diagnoses. We ascertained initial symptoms from baseline SCID and clinical assessments, applying AMDP and Bonn psychopathology schemes systematically to describe a broad range of features. Final consensus diagnoses were based on intake and follow-up SCID assessments, family interviews, and medical records. Factor-analytic methods defined first-episode symptom-clusters (Factors), and multiple-regression modeling related identified factors to initial DSM-IV diagnoses and to later categories (affective, non-affective, or schizoaffective disorders).

RESULTS

Psychopathological features were accommodated by four factors: I represented mania with psychosis; II a mixed depressive-agitated state; III an excited-hallucinatory-delusional state; IV a disorganized-catatonic-autistic state. Each factor was associated with characteristic prodromal symptoms. Factors I and III associated with DSM-IV mania, II with major depression or bipolar mixed-state, III negatively with delusional disorder, IV with major depression and negatively with mania. Factors I and II predicted later affective diagnoses; absence of Factor I features predicted non-affective diagnoses, and no Factor predicted later schizoaffective diagnoses.

CONCLUSION

The findings contribute to descriptive categorizations of psychopathology from onset of dissimilar psychotic illnesses. This approach was effective in identifying and subtyping affective psychotic disorders early in their clinical evolution, but non-affective and schizoaffective conditions appear to be more complex and unstable.

Classification for clinical practice: how to make ICD and DSM better able to serve clinicians

With DSM-V and ICD-11 on the horizon, now is an excellent time to consider options for improving their utility in clinical practice. A prerequisite for determining what can be done to improve their clinical utility is to establish a baseline from which to work. Surprisingly, there is virtually no information available that illuminates how clinicians actually use the DSM-IV and ICD-10 in clinical practice settings. Our first recommendation is for studies to be conducted that examine how the DSM-IV and ICD-10 is being used in the field and then to identify areas in need of improvement. We then propose two new diagnostic approaches to be considered that might significantly improve the system's clinical utility: (1) the addition of clinically useful dimensions (i.e., dimensions for indicating disorder severity, dimensions that cut across various disorders that would quantify symptoms of particular treatment-relevance such as psychosis, and dimensions to measure functioning) and (2) the augmentation of the DSM and ICD operationalized diagnostic criteria with the addition of a prototype-matching system that is likely to more closely conform to the way clinicians think about psychiatric diagnoses.

Shared and specific susceptibility loci for schizophrenia and bipolar disorder: a dense genome scan in Eastern Quebec families

The goal of this study was to identify susceptibility loci shared by schizophrenia (SZ) and bipolar disorder (BP), or specific to each. To this end, we performed a dense genome scan in a first sample of 21 multigenerational families of Eastern Quebec affected by SZ, BP or both (N=480 family members). This probably constitutes the first genome scan of SZ and BP that used the same ascertainment, statistical and molecular methods for the concurrent study of the two disorders. We genotyped 607 microsatellite markers of which 350 were spaced by 10 cM and 257 others were follow-up markers in positive regions at the 10 cM scan. Lander and Kruglyak thresholds were conservatively adjusted for multiple testings. We maximized the lod scores (mod score) over eight combinations (2 phenotype severity levels x 2 models of transmission x 2 analyses, affected/unaffected vs affected-only). We observed five genomewide significant linkages with mod score >4.0: three for BP (15q11.1, 16p12.3, 18q12-q21) and two for the shared phenotype, that is, the common locus (CL) phenotype (15q26,18q12-q21). Nine mod scores exceeded the suggestive threshold of 2.6: three for BP (3q21, 10p13, 12q23), three for SZ (6p22, 13q13, 18q21) and three for the CL phenotype (2q12.3, 13q14, 16p13). Mod scores >1.9 might represent confirmatory linkages of formerly reported genomewide significant findings such as our finding in 6p22.3 for SZ. Several regions appeared to be shared by SZ and BP. One linkage signal (15q26) appeared novel, whereas others overlapped formerly reported susceptibility regions. Despite the methodological limitations we raised, our data support the following trends: (i) results from several genome scans of SZ and BP in different populations tend to converge in specific genomic regions and (ii) some of these susceptibility regions may be shared by SZ and BP, whereas others may be specific to each. The present results support the relevance of investigating concurrently SZ and BP within the same study and have implications for the modelling of genetic effects.

Interaction between the tryptophan hydroxylase gene and the serotonin transporter gene in schizophrenia but not in bipolar or unipolar affective disorders

Increasing focus is being given to identify possible combinations of genes related to specific clinical phenotypes. In our sample of 814 patients comprising 114 with schizophrenia, 416 with bipolar affective disorder and 284 with unipolar affective disorder, we studied interactions between the tryptophan hydroxylase (TPH), the serotonin transporter (5-HTTLPR), and the dopamine receptor (DRD4) genes in relation to five major psychiatric symptomatology scores. There was significant interaction between the TPH and the 5-HTTLPR genes. With an increasing number of short (s) alleles of 5-HTTLPR, the scores for delusions, disorganization and negative symptoms were significantly decreasing among subjects having the TPH genotype AA but increasing among subjects having the TPH genotype AC, yielding the highest scores for the combinations AA x ll and AC x ss. Since high scores on just delusions, disorganization and negative symptoms but low scores on excitement and depression were found among subjects with schizophrenia, we conducted comparisons among the three diagnostic categories and controls as regards the combined TPH x 5-HTTLPR genotype distribution. Schizophrenia subjects had a significantly different distribution of the genotype combination for TPH x 5-HTTLPR as compared to 241 controls or to unipolar or bipolar subjects, and had significantly higher frequencies of AA x ll and of AC x ss. Thus, an interaction between TPH and 5-HTTLPR genes constitutes susceptibility to schizophrenia, thereby yielding apparent relationships between the major psychiatric symptomatology scores and genotype combinations in samples that are obtained by pooling schizophrenia with other diagnostic categories.

Profiles of "manic" symptoms in bipolar I, bipolar II and major depressive disorders

BACKGROUND

Classical authors such as Kraepelin, as well as the emerging literature during the past decade, indicate that manic-like signs and symptoms are present to a variable degree in all mood disorders. Current nosography does not differentiate between them and only the number of symptoms or severity is used for classification. This is particularly true for mania and hypomania. This paper will analyze the patterns of manic symptoms in bipolar I (BP-I), bipolar II (BP-II) and major depressive disorders (MDD), to test the hypothesis that mania and hypomania have different profiles, and ascertain which excitatory manic phenomena do occur in unipolar MDD.

METHODS

Six hundred and fifty-two inpatients (158 BP-I, 122 BP-II and 372 MDD) were assessed using the operational criteria for psychotic illness checklist (OPCRIT) [Arch. Gen. Psychiatry 48 (1991) 764] with a lifetime perspective. Manic or hypomanic symptoms were investigated and compared between BP-I, BP-II and MDD.

RESULTS

When compared with BP-II, BP-I disorder had a higher prevalence of reckless activity, distractibility, psychomotor agitation, irritable mood and increased self-esteem. These five symptoms correctly classified 82.8% of BP-I and 80.1% of BP-II patients. One or two manic symptoms were observed in more than 30% of major depressive patients; psychomotor agitation was the most frequent manifestations present in 18% of the MDD group.

LIMITATIONS

We did not control for severity of symptoms, nor for neuroleptic use that could produce akathisia.

CONCLUSIONS

This study suggests that mania and hypomania can be differentiated in their symptom profiles, and highlights the presence of few manic symptoms, particularly psychomotor agitation, in MDD. From the standpoint of number of manic signs and symptoms, controlling for psychomotor agitation did not substantially change the predictive power of the remaining manic symptoms. Given that excitatory manic signs and symptoms are present to a decreasing degree in BP-I, BP-II and MDD, these disorders can be proposed to lie along a dimensional model. Overall, these data are compatible with the concept of a bipolar spectrum, whereby each of the affective subtypes requires specific genetic factors.

Stability in schizophrenia symptoms over time: Findings from the Mount Sinai Pilgrim Psychiatric Center Longitudinal Study

This study examined the stability of symptoms of schizophrenia over time, focusing on the stability of symptom structure. Symptoms were assessed with the Positive and Negative Syndrome Scale (PANSS). The sample consisted of 215 chronic patients followed up for as long as 4 years. Exploratory factor analysis identified 6 factors. Several statistical techniques were used to examine the stability of these symptoms, including longitudinal confirmatory factor analysis. Low-to-moderate rank-order stability and high absolute stability of the factors were found, with the structure of the PANSS-assessed symptoms consistent over time. The results demonstrate that despite changes in the severity of symptoms in individual patients with schizophrenia, the factor structure and interrelatedness of symptoms have considerable stability over time.

DRD4 exon 3 variants are not associated with symptomatology of major psychoses in a German population

We previously reported an association of DRD4 exon 3 long alleles with delusional symptomatology, independently from psychiatric diagnoses [Am. J. Med. Genet. 105 (2001) 283; Psychiatry Res. 80 (1998) 129]. The aim of this investigation was to replicate these results in an independent sample from Germany. We studied 394 subjects, affected by bipolar disorder (n = 32), schizoaffective disorder (n = 45), and schizophrenia (n = 317). All affected subjects were evaluated using the Operational Criteria for Psychotic Illness (OPCRIT) checklist. DRD4 variants were not associated with symptomatology of major psychosis. Our present results, obtained in an independent German sample, did not confirm the association between DRD4 variants and delusional symptomatology. However it should be considered that the original sample included a much higher rate of mood disorders and this could partially explain the discrepancy.

A polydiagnostic and dimensional comparison of epileptic psychoses and schizophrenia spectrum disorders

After establishing the validity of the Japanese version of the Operational Criteria Checklist for Psychotic Illness (OPCRIT), we applied it to 58 consecutive patients with epileptic psychoses (index group) and to age- and sex-matched controls with schizophrenia spectrum disorders (control group). Compared with the control group, the index group had a low family history of schizophrenia, high premorbid personality disorder and unemployment, abrupt or acute onset of psychosis, good recovery with single or multiple episodes, and low deterioration from a premorbid level of function. From 9% to 52% of the index group and 38% to 84% of the control group were diagnosed with schizophrenia according to the operational criteria used. The percentages of patients diagnosed with schizophrenia based on various diagnostic criteria in the two groups were similar. In the index group, a diagnosis of schizophrenia was more commonly made among patients with inter-ictal psychosis than among those with post-ictal psychosis. An exploratory factor analysis identified five factor solutions of manic, negative, depressive, vegetative, and positive symptoms. Although positive and negative factor values were lower in the index group than in the control group, the two groups shared a similar factor profile. These results indicate that the difference in symptomatology between the two groups was quantitative rather than qualitative.

Depressive syndrome in major psychoses: a study on 1351 subjects

The aim of this study was to investigate depressive symptomatology across distinct major psychiatric disorders. A total of 1351 subjects affected by major depressive disorder (MDD = 389), bipolar disorder (BP = 511), delusional disorder (DD = 93) and schizophrenia (SKZ = 358) were included in our study. Subjects were assessed using the Operational Criteria for Psychotic Illness checklist (OPCRIT). The most frequently represented depressive symptoms in MDD were Loss of energy/tiredness, Loss of pleasure, Poor concentration, and Sleep disorders. Compared with MDD, BP had higher occurrences of Agitated activity, Excessive sleep, and Increased appetite and/or Weight gain, as well as lower Loss of pleasure. In our sample, 32.3% and 26.8% of DD and SKZ, respectively, had quite consistent depressive symptomatology, with at least four or more depressive symptoms. The most common depressive symptoms were Sleep disorders, Poor concentration and Loss of energy/Tiredness, followed by Psychomotor symptoms in SKZ only. Excessive self-reproach, Suicidal ideation, and Appetite and/or Weight changes were more specific to mood disorders. Finally, compared with SKZ, DD suffered from more depressive symptoms and had more severe depressive symptomatology. A quite consistent level of depressive symptomatology is therefore present in subpopulations of delusional and schizophrenic subjects other than in affective subjects. We identified some symptoms that are common across all major psychoses and symptoms that are more specific to each group.

Dimensions of major psychoses: a confirmatory factor analysis of six competing models

The symptoms of major psychosis aggregate in factors. Models of one to eight dimensions have been reported. In the present study, we tested six competing factor models, based on the psychotic and affective items of the OPCRIT checklist, in a large sample (N = 1294) of patients diagnosed with DSM-IV schizophrenia (n = 460), bipolar disorder (n = 726) and delusional disorder (n = 108). Confirmatory factor analysis was used to test the following models: (1) unique psychotic dimension; (2) positive-manic items, negative-depressive items; (3) model 2 with the addition of a disorganized factor; (4A) positive, negative, depressive and manic dimensions; (4B) model 4A with loss of pleasure (Anhedonia) and loss of energy (Apathy) included among depressive instead of negative symptoms; and (5) same as model 4B except for the addition of a disorganized domain. The four- and five-factor models fit the data much better than simpler ones. Between the two four-factor models, M4B emerged as more appropriate than M4A. The five-factor solution (M5) displayed the best fit. In conclusion, our confirmatory factor analysis in a large sample of psychotic subjects indicated that the symptomatology of major psychoses is composed of the following five factors: mania, positive symptoms, disorganization, depression and negative symptoms.

Clinical phenotype of schizophrenia in a Finnish isolate

We identified all cases in Finland (population of 5 million) with a diagnosis of schizophrenia born between 1940 and 1969, using four national computerised registers with high reliability. A sample of 397 families was identified in a genetically homogeneous internal isolate (population of 18,000) in northeastern Finland with high prevalence for schizophrenia and an LOD score of 3.8 in chromosome 1. Our aim was to examine with Operational Criteria Checklist for Psychotic Illness (OCCPI) factor analysis the psychotic and affective signs and symptoms of schizophrenia in this genetically homogeneous population, and compare them with findings from individuals with schizophrenia from multiplex families from the whole country. After collecting all original case notes, we made DSM-IV consensus diagnoses and completed OCCPI ratings on a lifetime basis. For the factor analysis, we accepted 190 patients with a diagnosis of schizophrenia. In addition, 466 schizophrenia patients from 147 multiplex families from the whole country were included in the analysis. The OCCPI factor analysis resulted in four factors: "delusions and hallucinations" and "negative" factors, plus two affective ("manic" and "depressive") factors. We compared the pattern of symptoms among three patient groups: isolate patients who were the only affected individuals in their family, isolate patients who had affected family members, and patients from the whole country with affected family members. We found no clear differences among these groups. However, there were significant differences in the frequency of individual OCCPI items between the study groups. Findings in this schizophrenia OCCPI phenotype study suggest that the clinical picture of schizophrenia in a genetically isolated and homogeneous population closely resembles our nationwide findings in Finland.

Polymorphism of the serotonin transporter gene and symptomatic dimensions of schizophrenia in the Korean population

This study was aimed to test the association between schizophrenia and a functional serotonin polymorphism (5-HTTLPR) in the upstream regulatory region. Genomic DNA analysis with polymerase chain reaction was used for 5-HTTLPR genotyping. One hundred and eleven patients with schizophrenia and 208 healthy individuals participated in this study. There were significant differences in the negative score and general psychopathology score of the positive and negative syndrome scale according to 5-HTTLPR genotypes and alleles, although no significant differences in allele or genotype frequencies between the two groups were found. These results suggest that 5-HTTLPR may contribute to the susceptibility to the symptomatology of schizophrenia but not to the development of the disorder itself, at least in the Korean population.

Multicentre Italian family-based association study on tyrosine hydroxylase, catechol-O-methyl transferase and Wolfram syndrome 1 polymorphisms in mood disorders

OBJECTIVE

The aim of the present study was to investigate tyrosine hydroxylase, catechol-O-methyl transferase and Wolfram syndrome 1 genes in mood disorders using a family-based association approach.

METHODS

The sample included 134 nuclear mood disorder families, with subjects affected by bipolar disorder (n=103) or major depressive disorder (n=58). All subjects were genotyped using polymerase chain reaction techniques.

RESULTS

No significant transmission disequilibrium was found in the overall sample for any polymorphism. Analysis considering bipolar subjects only, or psychopathology traits as affection status did not influence the observed results.

CONCLUSIONS

The study could not support the involvement of tyrosine hydroxylase, catechol-O-methyl transferase and Wolfram syndrome 1 polymorphisms in mood disorders.

Clinical and demographic features of mood disorder subtypes

The aim of this study was to investigate demographic, clinical and symptomatologic features of the following mood disorder subtypes: bipolar disorder I (BP-I); bipolar disorder II (BP-II); major depressive disorder, recurrent (MDR); and major depressive episode, single episode (MDSE). A total of 1832 patients with mood disorders (BP-I=863, BP-II=141, MDR=708, and MDSE=120) were included in our study. The patients were assessed using structured diagnostic interviews and the operational criteria for psychotic illness checklist (n=885), the Hamilton depression rating scale (n=167), and the social adjustment scale (n=305). The BP-I patients were younger; had more hospital admissions; presented a more severe form of symptomatology in terms of psychotic symptoms, disorganization, and atypical features; and showed less insight into their disorder than patients in the other groups. Compared with the major depressive subgroups, BP-I patients were more likely to have an earlier age at onset, an earlier first lifetime psychiatric treatment, and a greater number of illness episodes. BP-II patients had a higher suicide risk than both BP-I and MDSE patients. MDSE patients presented less severe symptomatology, lower age at observation, and a higher number of males. The retrospective approach and the selection constraints due to the inclusion criteria are the main limitations of the study. Our data support the view that BP-I disorder is quite different from the remaining mood disorders from a demographic and clinical perspective, with BP-II disorder having an intermediate position to MDR and MDSE, that is, as a less severe disorder. This finding may help in the search for the biological basis of mood disorders.

Family-based association study of 5-HTTLPR, TPH, MAO-A, and DRD4 polymorphisms in mood disorders

Variants of the functional polymorphism in the serotonin transporter (upstream regulatory region: 5-HTTLPR), the tryptophan hydroxylase (TPH), the monoamine oxidase A (MAO-A), and the dopamine receptor D4 (DRD4) genes have all been associated with mood disorders. The aim of this study was to test those hypotheses by using a family-based association approach. Both diagnoses and psychopathology were used for phenotype definitions. A total of 134 nuclear families with mood disorders, with probands affected by bipolar (n = 103) or major depressive (n = 58) disorders, were included in the study. All subjects were typed for the above-mentioned gene variants using polymerase chain reaction (PCR) technique. No significant transmission disequilibrium was found in the overall sample for any polymorphism. A separate analysis of bipolar subjects only, or the use of continuous psychopathologic traits as affectation status did not influence the observed results. Our study did not support the involvement of 5-HTTLPR, TPH, MAO-A, or DRD4 polymorphisms in mood disorders.

Serotonin transporter gene (5-HTTLPR) and major psychoses

Serotoninergic neurotransmitter systems have been implicated in the pathogenesis of major psychoses. A functional polymorphism (5-HTTLPR) in the upstream regulatory region of the gene (SLC6A4) has been associated with a number of psychiatric disturbances, but conflicting replication followed. The aim of this study was to investigate the possibility that the 5-HTTLPR might be associated with major psychoses. One thousand, eight hundred and twenty inpatients (789 bipolars, 667 major depressives, 66 delusionals, 261 schizophrenics, 37 psychotics not otherwise specified-NOS) and 457 control subjects were included in this study. A subsample of 1235 patients (523 bipolars, 359 major depressives, 259 schizophrenics, 66 delusionals, 28 psychotic NOS) were evaluated for lifetime psychotic symptomatology using the Operational Criteria for Psychotic illness (OPCRIT) checklist. The subjects were also typed for 5-HTTLPR variants using PCR techniques. 5-HTTLPR allele frequencies were not significantly different between controls and bipolars, major depressives, schizophrenics, delusionals and psychotic NOS; genotype analysis also did not show any association. The analysis of symptomatology did not show significant differences. Consideration of possible stratification factors such as sex and age of onset did not significantly influence results. 5-HTTLPR variants are not therefore a liability factor for major psychoses or for major psychoses symptomatology.

DRD4 exon 3 variants associated with delusional symptomatology in major psychoses: a study on 2,011 affected subjects

We previously reported an association of DRD4 exon3 long allele variants with delusional symptomatology independently from diagnoses. The aim of this investigation was to study DRD4 in major psychoses and to test the association in a larger sample. We studied 2,011 inpatients affected by bipolar disorder (n = 811), major depressive disorder (n = 635), schizophrenia (n = 419), delusional disorder (n = 104), psychotic disorder not otherwise specified (n = 42), and 601 healthy controls. A subsample of 1,264 patients were evaluated using the OPCRIT checklist and differences of symptomatology factor scores among genetic variants were assessed using one-way analysis of variance (ANOVA). DRD4 allele and genotype frequencies in bipolars, schizophrenics, delusionals, and psychotic NOS were not significantly different from controls; major depressives showed a trend toward an excess of DRD4*Short and DRD4*Short/Short variants versus controls. The ANOVA on factor scores in the whole subsample of 1,264 subjects showed a significant difference on delusion factor in allele analysis (P = 0.007), and in genotype one (P = 0.018), with DRD4*Long containing variants associated with severe symptomatology. The analysis in the replication subjects only (n = 803) showed a trend in the same direction, though not reaching the significance level. This analysis in an enlarged sample suggests that DRD4*Long alleles exert a small but significant influence on the delusional symptomatology in subjects affected by major psychoses.

Integrating psychopathological dimensions in functional psychoses: a hierarchical approach

Previous factor analysis studies of psychotic symptomatology have demonstrated three psychopathological dimensions: positive, negative and disorganization. However, few studies have analyzed non-schizophrenic samples and most use a syndrome-level of analysis or only schizophrenic symptom scales. This study examined how many dimensions underlie psychosis, and whether within psychosis there is a hierarchical organization of dimensions.A total of 660 inpatients with an acute psychotic episode were studied. Psychopathology was measured through a wide psychopathological assessment using the Manual for the Assessment and Documentation of Psychopathology (AMDP-system). Principal component factor analysis was carried out on 64 psychopathological symptoms scoring 1 or higher in at least 10% of the sample. A 15-factor solution was obtained which failed to depict a psychosis model on clinical and methodological grounds. Further predetermined factor analyses ranging from 1 to 15 factors were carried out to examine alternative factor solutions. A 10-dimensional model was the best model on clinical, statistical and conceptual grounds. Moreover, the examination of the 1 to 10 dimensional models allowed us to infer a hierarchical model of psychopathological dimensions, which can be represented in the frame of a tree-structure. The model permitted transitions between psychiatric categories and psychopathological dimensions, and it was able to integrate previous factor solutions with different numbers of resulting dimensions.The findings have implications for the design of future studies and for the hierarchical conceptualization of psychopathological dimensions.

Tryptophan hydroxylase gene and major psychoses

Disturbances of the serotoninergic neurotransmitter system have been implicated in the pathogenesis of mood disorders. The tryptophan hydroxylase (TPH) gene, which codes for the rate-limiting enzyme of serotonin biosynthesis, has been recently reported to be associated with bipolar disorder. In this study, we investigated TPH A218C gene variants in a sample of subjects affected by major psychoses. One thousand four hundred and twenty-four inpatients affected by bipolar (n=627), major depressive (n=511), schizophrenic (n=210), delusional (n=48) disorder and psychotic disorder not otherwise specified (n=27) (DSM-IV) were included; all patients and 380 controls were typed for the TPH variants using PCR techniques. A sub-sample of 963 patients was assessed using the Operational Criteria for Psychotic Illness (OPCRIT). TPH variants were not associated with major psychoses, but a trend was observed toward an excess of TPH*A/A in bipolar disorder. The analysis of symptomatology factors did not show any significant difference either; however, a trend was observed for males with the TPH*A genotype to have lower depressive symptoms compared with TPH*C subjects. Possible stratification factors such as current age and age of onset did not affect the observed results. TPH A218C variants are not, therefore, a major liability factor for the symptoms of major psychoses to have in the present sample. TPH*A containing variants may be a protective factor for depressive symptoms among male subjects with mood disorders or for a subtype of mood disorders characterized by a mainly manic form of symptomatology.

A factor analysis of signs and symptoms of the manic episode with Bech-Rafaelsen Mania and Melancholia Scales

BACKGROUND

Several factor analyses of signs and symptoms of mania have been reported using different rating scales. We propose here that the use of two instruments well known in the European literature may be useful in detecting the structure of manic episodes.

METHOD

We investigated the pattern of symptoms in a group of 124 bipolar inpatients hospitalised for a manic episode. We conducted a factor analysis of the broad range of psychiatric symptoms covered by the Bech-Rafaelsen Mania Scale (BRMaS) and Melancholia Scale (BRMeS).

RESULTS

Five eigen values were greater than unity, which determined the number of factors computed. The five factors captured 66.7% of the total variance. Following rotation, five factors were clinically relevant.

CONCLUSION

This suggests that both euphoric activation and depression are prominent in this sample.

How many and which are the psychopathological dimensions in schizophrenia? Issues influencing their ascertainment

During the last two decades, much effort has been made to precisely characterize the symptom dimensions of schizophrenia. A number of dimensional models have been proposed, the most popular of which has been a three-dimensional model consisting of psychotic, negative and disorganizational symptoms. This model, however, has been criticized as too simplistic, and more complex models have been proposed, although to date there has been no consensus as to the number and nature of dimensions necessary to account for the whole range of schizophrenic symptoms. In the present paper, the authors review the main methodological issues which have led to the current confusion about the number of dimensions underlying schizophrenic psychopathology. Among the main issues influencing the delimitation of dimensions are: statistical procedures for determining the number of factors, phase of the illness, level of analysis of symptoms (i.e., symptoms or groups of symptoms), and measurement instrument used. Studies analyzing either a broad range of symptoms or particular symptoms at a finer level have produced a rather complex picture of schizophrenic dimensions. There is evidence supporting the existence of eight major dimensions of psychopathology: psychosis, disorganization, negative, mania, depression, excitement, catatonia and lack of insight. The dimensional structure of symptoms becomes even more complex if one considers that these big dimensions can be further divided into more elementary components. A hierarchical approach for organizing the complex dimensional structure of schizophrenic symptoms is proposed.

Suspiciousness as a specific risk factor for major depressive episodes in schizophrenia

OBJECTIVE

Serious depression is a common and important complication of schizophrenia. In a prospective, population-based study, we tested the hypothesis that suspiciousness increases the risk for the later development of depression in schizophrenia.

METHOD

Data came from the Epidemiological Catchment Area (ECA) study. Baseline clinical and demographic features were used to predict the onset of new episodes of depression at 1 year follow-up. As ECA diagnoses were based on lay interviews, which may have low sensitivity compared with clinical diagnoses, two overlapping groups of putative schizophrenia patients were defined.

RESULTS

Suspiciousness was associated with an increased risk of new episodes of depression in both patient groups, after accounting for demographic variables. There was no association between an increased risk of depression and either disorganization or hallucinations and delusions.

CONCLUSIONS

Suspiciousness appears to be a specific risk factor for depression in psychotic groups. Interventions that decrease suspiciousness, or mitigate its isolating effects, might decrease the risk of serious depression and suicide.

Melancholic features and response to lithium prophylaxis in mood disorders

Clinical predictors of the efficacy of lithium prophylaxis in mood disorders have great potential value. Melancholic features during depressive phases have been both proposed and rejected as valid predictors of favorable outcome. The aim of the present study is to describe the validity of melancholic features during depressive phases as predictors of the prophylactic efficacy of lithium. Sixty-one subjects affected by bipolar (n = 51) and major depressive (n = 10) disorder were followed prospectively for an average of 53 months. All subjects were evaluated as a lifetime perspective at intake, by the Operational Criteria checklist for psychotic illness (OPCRIT). Melancholic features were correlated with outcome only when controlling for time of first lithium administration. These two variables accounted for more than 30% of the total variance in lithium response. Others clinical factors such as polarity, delusions, gender, onset, personality disorders, and family history of mood disorders did not influence the observed association. Our preliminary findings suggest that melancholic features may be associated with favorable lithium prophylactic outcome in mood disorders.

Dopamine receptor D2 Ser/Cys 311 variant is associated with delusion and disorganization symptomatology in major psychoses

The D2 receptor (DRD2) is a binding site of many psychoactive drugs and it has been proposed as a genetic risk factor for psychiatric disorders. The aim of this investigation was to study the DRD2 S311C variant in major psychoses. We studied 1182 inpatients with diagnoses of bipolar disorder (n = 480), major depressive disorder (n = 269), schizophrenia (n = 366), delusional disorder (n = 44), psychotic disorder not otherwise specified (n = 23) and 267 healthy controls. Eight hundred and eighty-seven subjects were also scored for their lifetime symptomatology using the the Operational Criteria checklist for psychotic illness (OPCRIT). DRD2 variants were not associated with affected subjects even when possible confounders like gender and onset were considered. When we considered the 887 subjects with the symptomatologic analysis, we observed a significant association of the DRD2 S311C variant with both delusion and disorganization features. The association was present independently from diagnoses. Our results do not show that coding variants of the DRD2 S311C play a major role in conferring susceptibility to major psychoses, but they may be connected with disorganized and delusional symptomatology independently from diagnoses.

Serotonin-2C and serotonin-1A receptor genes are not associated with psychotic symptomatology of mood disorders

The serotonergic system is involved in both pathophysiology and treatment of mood disorders. In the present study we investigated the possible influence of the polymorphisms of the serotonin-1A and 2C receptor genes on the symptomatology of mood disorders. Eighty-four inpatients affected by mood disorders (72 bipolar and 12 major depressive disorder) were assessed by the Operational Criteria Checklist for Psychotic Illness to score their lifetime psychotic symptomatology. The subjects were also typed for 5HT1A and 5HT2C variants using polymerase chain reaction techniques. No association was found between 5HT2C and psychopathology as defined by the four symptomatologic factors used as phenotype definition (mania, depression, delusion, and disorganization) even when bipolar subjects were analyzed separately. Only one subject with the 5HT1A variant was observed. Genetic variation at the 5HT1A and 5HT2C receptor genes does not, therefore, play a major role in the pathogenesis of mood disorders symptomatology. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:161-166, 2000.

Pharmacogenetics of antipsychotic treatment: lessons learned from clozapine

The reintroduction of clozapine, the prototype of atypical antipsychotics, in the late 1980s has led to significant advances in the pharmacological management of schizophrenia. Since then, there has been a rapid development of novel "atypical" antipsychotic agents that have been pharmacologically modeled, to a certain extent, after their predecessor clozapine. As with all antipsychotics, there is variability among individuals in their response to these "atypical" drugs. Pharmacogenetics can provide a foundation for understanding this interindividual variability in antipsychotic response. This review first provides a rationale for the pharmacogenetic investigation of this variable trait. Studies of pharmacokinetic and pharmacodynamic factors of antipsychotic therapy are considered in the development of this rationale. Next, the molecular genetic techniques used to study this interindividual variation in response are described. This is followed by a review and discussion of the published studies examining genetic factors involved in clozapine response. From this, several recommendations for future pharmacogenetic investigations of antipsychotic response are proposed. Although still in its early stages, psychiatric pharmacogenetics should provide a basis for individualized pharmacotherapy of schizophrenia, and may also lead to the development of newer, more efficacious antipsychotic agents.

No association between serotonin-2A receptor gene polymorphism and psychotic symptomatology of mood disorders

Abnormalities of the serotonergic system are involved in the pathophysiology of mood disorders. In the present study, we investigated the possible influence of the T102C polymorphism of the serotonin-2A receptor gene (5-HT2A, 13q14-21) on the symptomatology of mood disorders. Inpatients affected by mood disorders (n = 246, 149 bipolar, 97 major depressive disorder) were assessed with a checklist of operational criteria for psychotic illness (OPCRIT) to score their lifetime psychotic symptomatology. The subjects were also typed for 5-HT2A variants using polymerase chain reaction techniques. No association was found between this polymorphism and psychopathology as defined by the four symptomatologic factors used in phenotype definition (mania, depression, delusion and disorganization). Genetic variation at the 5-HT2A receptor gene does not, therefore, appear to play a major role in the pathogenesis of major mood disorders.

Serotonin transporter gene not associated with psychotic symptomatology of mood disorders

A functional polymorphism in the upstream regulatory region of the serotonin transporter gene (5-HTTLPR) has been recently reported to be associated with mood disorders. In the present study we investigated the possible influence of 5-HTTLPR on the symptomatology of mood disorders. Two hundred and thirty inpatients affected by mood disorders (160 bipolar and 70 major depressive disorder) were assessed by the Operational Criteria checklist for psychotic illness (OPCRIT) and were also typed for the 5-HTTLPR variants using PCR techniques. Mania, Depression, Delusion and Disorganization were the four symptomatologic factors used as phenotype definition. 5-HTTLPR variants were not associated with these symptomatologic factors, and consideration of possible stratification effects, such as sex, age of onset and polarity, did not reveal any association either. The serotonin transporter gene does not, therefore, appear to be associated with the symptomatology of mood disorders.

Dopamine D1 receptor gene polymorphism and schizophrenia in Japan

We studied the relationship between schizophrenia and the DdeI polymorphism in the 5' untranslated region (5'UTR) of the dopamine D1 receptor (DRD1) gene. This polymorphism is an A (A1 allele) to G (A2 allele) transition in the 5' UTR of exon 2 at bp -48 (A-48G). One hundred forty-eight schizophrenics and 148 control subjects were investigated. No significant differences in genotypic counts and allele frequencies between schizophrenics and controls were found. Although a significant difference between the patients classified as disorganized type and the controls was discovered both in genotypic counts and allele frequencies, neither association proved significant when a Bonferroni correction was used. Moreover, there were no differences in scores of main symptoms of schizophrenia based on the Manchester Scale between patients with A1/A1 genotype and those with A1/A2 genotype. These findings suggest that this gene may not be involved in the pathogenesis of schizophrenia.

Factor analysis of delusional disorder symptomatology

Delusional disorder symptomatology has been poorly investigated with factor analytic studies. Most attempts to identify its symptomatologic structure were made with schizophrenic or mixed psychotic populations and included only delusional symptoms. The purpose of this study was to analyze the whole symptomatologic structure of delusional disorder. One hundred eight inpatients with delusional disorder (DSM-III-R) were evaluated for lifetime symptoms using the Operational Criteria (OPCRIT) checklist for psychotic illness and included in a factorial analysis. Four factors were evaluated: (1) core depressive symptoms, (2) hallucinations, (3) delusions, and (4) irritability symptoms. Thus, when scored by the OPCRIT checklist, delusional symptomatology consisted of four independent factors, indicating a substantial heterogeneity of this diagnostic category.

Serotonin transporter gene is not associated with symptomatology of schizophrenia

The serotonin transporter gene is a primary candidate for involvement in major psychoses. A functional polymorphism in the upstream regulatory region of the serotonin transporter gene (5-HTTLPR) has recently been reported to be associated with a variety of psychopathological conditions. In the present study, we investigated the potential influence of the 5-HTTLPR on the psychopathology of schizophrenia. One hundred and sixty-one inpatients affected by schizophrenia (DSMIII-R) were assessed by the Operational Criteria checklist for psychotic illness (OPCRIT) and were typed for their 5-HTTLPR variants by PCR techniques. Mania, Depression, Delusion and Disorganization were the four symptomatologic factors used to define phenotype. 5-HTTLPR variants were not associated with these symptomatologic factors, and consideration of possible stratification effects such as sex, and age of onset did not reveal any association either. The serotonin transporter gene is not a liability factor for the symptomatology of schizophrenia.

Dopamine receptor D2 Ser/Cys311 variant associated with disorganized symptomatology of schizophrenia

The dopamine D2 receptor gene has been proposed as a genetic risk factor for schizophrenia (Arinami et al., 1994). However, a number of replications failed to confirm the initial report. The finding of a stronger association considering schizophrenics with the absence of negative symptoms (Arinami et al., 1996) suggested that the influence of DRD2 variants should be analyzed more at the level of symptoms rather than syndromes. One hundred and four inpatients affected by schizophrenia (n = 99) and delusional disorder (n = 5) (DSM IV) were assessed at admission by the Operational Criteria for Psychotic Illness (OPCRIT) and were typed for DRD2 variants using polymerase chain reaction (PCR) techniques. Subjects with the S311C variant presented a higher score on the 'Disorganization' factor (P = 0.012). Consideration of possible stratification effects such as sex and age of onset did not reveal any deviation from the whole sample. In conclusion, our preliminary report suggests that the DRD2 S311C variant may be a liability factor for disorganized symptoms among schizophrenics or for a subtype of schizophrenia characterized by highly disorganized symptomatology.

Dopamine receptor D4 gene is associated with delusional symptomatology in mood disorders

Disturbances of the dopaminergic neurotransmitter system have been implicated in the pathogenesis of depressive symptoms. Many studies have, however, failed to detect any association between genetic markers for the dopamine system and mood disorders. A possible reason for this may lie in the definition of phenotype, which is traditionally based on psychiatric diagnosis. In this study, we investigated the possibility that functional variants of the dopamine D4 receptor (DRD4) gene might be associated with depressive symptomatology in a sample of mood disorder subjects. Seventy-nine inpatients affected by bipolar (n=37) and major depressive (n=42) disorder (DSM-IV) were assessed at admission by the Hamilton Depression Rating Scale and were typed for DRD4 variants at the third exon using polymerase chain reaction (PCR) techniques. DRD4 was associated with delusional symptoms (F=5.56; d.f.=2,145; P=0.005), with DRD4*7 exhibiting higher scores when compared to DRD4*4 (P=0.006) variants. Polarity of mood disorder did not influence results significantly. The findings are in accordance with our previous report of an association of the DRD4 gene with delusional symptomatology of major psychoses. DRD4*7 should, therefore, be considered a liability factor for delusional symptoms in mood disorders.