European Collaborative Project on Affective Disorders: interactions between genetic and psychosocial vulnerability factors

Association of chronic hepatitis C with recurrent brief depression

BACKGROUND

Depressive syndromes, including recurrent brief depression (RBD), have frequently been observed in association with chronic diseases characterized by immune activation, such as autoimmune thyroiditis or celiac disease. However, the association of RBD with chronic hepatitis C (CHC), a disease with an increased incidence of major depressive disorders, is unknown.

CASES

135 (83 males, 52 females) consecutive treatment-naïve patients with CHC.

EXCLUSION CRITERIA

previous treatment with IFN-alpha, co-infection with hepatitis C virus (HCV) and hepatitis B virus, infection with human immunodeficiency virus (HIV), drug or alcohol abuse, or malignancy.

CONTROLS

540 (332 males, 208 females) subjects without evidence of hepatitis, randomly extracted from the database of a previous epidemiological study. The psychiatric diagnosis was based on the Composite International Diagnostic Interview Simplified (CIDI-S), containing a specific section on RBD.

RESULTS

A significantly higher rate of RBD was observed among both male and female patients with CHC (n=21, 15.5%) as compared to controls (n=34, 6.3%) (OR=2.6, CI 95% from 1.37 to 4.93).

CONCLUSION

The present study provides the first evidence of an association between CHC and RBD, independent of treatment with IFN-alpha and not influenced by substance or alcohol abuse. The results are similar to those found in other conditions with immune activation. RBD may be another expression of mood disorders in such conditions.

Lack of genetic association between the phospholipase A2 gene and bipolar mood disorder in a European multicentre case-control study

The possible association between phospholipase A2 gene and bipolar mood disorder was examined in 557 bipolar patients and 725 controls (all personally interviewed), recruited from seven countries (Belgium, Bulgaria, Croatia, Germany, Greece, Italy, and UK). The frequencies of the eight alleles that were identified did not differ between patients and control individuals in the whole population, while the power to detect an association based on our sample was relatively high. Some differences were noted among the various ethnic groups, but no significant trends existed, suggesting that population stratification by country may not be responsible for a type II error. On the basis of these results, mutations of the phospholipase A2 gene, at least in the region close to the polymorphism examined between exons 1 and 2, are not involved in the pathogenesis of bipolar mood disorder.

Association between COMT (Val158Met) functional polymorphism and early onset in patients with major depressive disorder in a European multicenter genetic association study

The available data from preclinical and pharmacological studies on the role of the C-O-methyl transferase (COMT) support the hypothesis that abnormal catecholamine transmission has been implicated in the pathogenesis of mood disorders (MD). We examined the relationship of a common functional polymorphism (Val108/158Met) in the COMT gene, which accounts for four-fold variation in enzyme activity, with 'early-onset' (EO) forms (less than or equal to 25 years) of MD, including patients with major depressive disorder (EO-MDD) and bipolar patients (EO-BPD), in a European multicenter case-control sample. Our sample includes 378 MDD (120 EO-MDD), 506 BPD (222 EO-BPD) and 628 controls. An association was found between the high-activity COMT Val allele, particularly the COMT Val/Val genotype and EO-MDD. These findings suggest that the COMT Val/Val genotype may be involved in EO-MDD or may be in linkage disequilibrium with a different causative polymorphism in the vicinity. The COMT gene may have complex and pleiotropic effects on susceptibility and symptomatology of neuropsychiatric disorders.

Genetic association between the phospholipase A2 gene and unipolar affective disorder: a multicentre case-control study

The co-segregation in one pedigree of bipolar affective disorder with Darier's disease whose gene is on chromosome 12q23-q24.1, and findings from linkage and association studies with the neighbouring gene of phospholipase A2 (PLA2) indicate that PLA2 may be considered as a candidate gene for affective disorders. All relevant genetic association studies, however, were conducted on bipolar patients. In the present study, the possible association between the PLA2 gene and unipolar affective disorder was examined on 321 unipolar patients and 604 controls (all personally interviewed), recruited from six countries (Belgium, Bulgaria, Croatia, Germany, Greece, and Italy) participating in the European Collaborative Project on Affective Disorders. After controlling for population group and gender, one of the eight alleles of the investigated marker (allele 7) was found to be more frequent among unipolar patients with more than three major depressive episodes than among controls (P<0.01); genotypic association was also observed, under the dominant model of genetic transmission (P<0.02). In addition, presence of allele 7 was correlated with a higher frequency of depressive episodes (P<0.02). These findings suggest that structural variations at the PLA2 gene or the chromosomal region around it may confer susceptibility for unipolar affective disorder.

Serotonin transporter 5HTTLPR polymorphism and affective disorders: no evidence of association in a large European multicenter study

The available data from preclinical and pharmacological studies on the role of the serotonin transporter (5-HTT) support the hypothesis that a dysfunction in brain serotonergic system activity contributes to the vulnerability to affective disorders (AD). 5-HTT is the major site of serotonin reuptake into the presynaptic neuron, and it has been shown that the polymorphic repeat polymorphism in the 5-HTT promotor region (5-HTTLPR) may affect gene-transcription activity. 5-HTT maps to chromosome 17 at position 17q11.17-q12, and the 5-HTTLPR polymorphisms have been extensively investigated in AD with conflicting results. The present study tested the genetic contribution of the 5-HTTLPR polymorphism in a large European multicenter case-control sample, including 539 unipolar (UPAD), 572 bipolar patients (BPAD), and 821 controls (C). Our European collaboration has led to efforts to optimize a methodology that attenuates some of the major limitations of the case-control association approach. No association was found with primary psychiatric diagnosis (UPAD and BPAD) and with phenotypic traits (family history of AD, suicidal attempt, and presence of psychotic features). Our negative findings are not attributable to the lack of statistical power, and may contribute to clarify the role of 5-HTTLPR polymorphism in AD.

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.

Lack of association between the 5HT2A receptor polymorphism (T102C) and unipolar affective disorder in a multicentric European study

We report here a case-control association study with T102C polymorphism in the serotonin 2A receptor gene (HTR2A) in patients affected by unipolar affective disorder (UPAD) and in controls. A total of 284 subjects were genotyped (142 UPAD and 142 controls). All subjects were interviewed using standard diagnostic interviews and matched. A homogenous population of unipolar patients with suicidal attempt was identified. Conditional logistic regression was applied. No association of the HTR2A polymorphism was found in the overall sample of 142 UPAD-control pairs regarding allele and genotype frequencies (P=0.36 and P=0.52 respectively) and homo-heterozygote distributions (P=0.91). This study confirms, in a multicentric European sample, the earlier observations that the T102C HTR2A polymorphism is not associated with UPAD. Nevertheless, a type 2 statistical error cannot be excluded. Therefore, to exclude the implication of HTR2A in UPAD, this result must be replicated in larger samples and in other populations using the transmission disequilibrium test and different polymorphisms around HTR2A.

Psychiatric genetics in Australia

Australian research in psychiatric genetics covers molecular genetic studies of depression, anxiety, alcohol dependence, Alzheimer's disease, bipolar disorder, schizophrenia, autism, and attention deficit hyperactivity disorder. For each disorder, a variety of clinical cohorts have been recruited including affected sib pair families, trios, case/controls, and twins from a large population-based twin registry. These studies are taking place both independently and in collaboration with international groups. Microarray studies now complement DNA investigations, while animal models are in development. An Australian government genome facility provides a high throughput genotyping and mutation detection service to the Australian scientific community, enhancing the contribution of Australian psychiatric genetics groups to gene discovery.

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.

Self-esteem, social adjustment and suicidality in affective disorders

Self-esteem (SE) and social adjustment (SA) are often impaired during the course of affective disorders; this impairment is associated with suicidal behaviour. The aim of the present study was to investigate SE and SA in unipolar or bipolar patients in relation to demographic and clinical characteristics, especially the presence of suicidality (ideation and/or attempt). Forty-four patients, 28 bipolar and 16 unipolar, in remission for at least 3 months, and 50 healthy individuals were examined through a structured clinical interview. SE and SA were assessed by the Rosenberg self-esteem scale and the social adjustment scale, respectively. The results have shown that bipolar patients did not differ from controls in terms of SE, while unipolar patients had lower SE than bipolars and controls. No significant differences in the mean SA scores were found between the three groups. Suicidality during depression was associated only in bipolar patients with lower SE at remission; similar but not as pronounced was the association of suicidality with SA. It is concluded that low SE lasting into remission seems to be related to the expression of suicidality during depressive episodes of bipolar patients, while no similar pattern is evident in unipolar patients.

Excess of allele1 for alpha3 subunit GABA receptor gene (GABRA3) in bipolar patients: a multicentric association study

The available data from preclinical and pharmacological studies on the role of gamma amino butyric acid (GABA) support the hypothesis that a dysfunction in brain GABAergic system activity contributes to the vulnerability to bipolar affective disorders (BPAD). Moreover, the localization of the alpha3 subunit GABA receptor GABRA3 gene on the Xq28, a region of interest in certain forms of bipolar illness, suggests that GABRA3 may be a candidate gene in BPAD. In the present study, we tested the genetic contribution of the GABRA3 dinucleotide polymorphism in a European multicentric case-control sample, matched for sex and ethnogeographical origin. Allele and genotype (in females) frequencies were compared in 185 BPAD patients and 370 controls. A significant increase of genotype 1-1 was observed in BPAD females compared to controls (P=0.0004). Furthermore, when considering recessivity of allele 1 (females with genotype 1-1 and males carrying allele 1), results were even more significant (P= 0.00002). Our findings suggest that the GABRA3 polymorphism may confer susceptibility to or may be in linkage disequilibrium with another gene involved in the genetic etiology of BPAD.

Pharmacogenetics of lithium prophylaxis in mood disorders: analysis of COMT, MAO-A, and Gbeta3 variants

We studied the possible association between the prophylactic efficacy of lithium in mood disorders and the following gene variants: catechol-O-methyltransferase (COMT) G158A, monoamine oxydase A (MAO-A) 30-bp repeat, G-protein beta 3-subunit (Gbeta3) C825T. A total of 201 subjects affected by bipolar (n = 160) and major depressive (n = 41) disorder were followed prospectively for an average of 59.8 months and were typed for their gene variants using PCR techniques. COMT, MAO-A, and Gbeta3 variants were not associated with lithium outcome, even when possible stratification effects such as sex, polarity, age at onset, duration of lithium treatment, and previous episodes were included in the model. The pathways influenced by those variants are not therefore involved with long-term lithium outcome in our sample.

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.

Serotonin transporter gene associated with lithium prophylaxis in mood disorders

The aim of this study was to investigate the possible association between the functional polymorphism in the upstream regulatory region of the serotonin transporter gene (5-HTTLPR) and the prophylactic efficacy of lithium in mood disorders. Two hundred and one subjects affected by bipolar (n = 167) and major depressive (n = 34) disorder were followed prospectively for an average of 58.2 months and were typed for their 5-HTTLPR variant using polymerase chain reaction techniques. 5-HTTLPR variants were associated with lithium outcome (F = 5.35; df = 2,198; P = 0.005). Subjects with the s/s variant showed a worse response compared to both l/s and l/l variants. Consideration of possible stratification effects such as sex, polarity, age at onset, duration of lithium treatment and previous episodes did not influence the observed association. 5-HTTLPR variants may be a possible influencing factor for the prophylactic efficacy of lithium in mood disorders.

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.

Variability of 5-HT2C receptor cys23ser polymorphism among European populations and vulnerability to affective disorder

Substantial evidence supports a role for dysfunction of brain serotonergic (5-HT) systems in the pathogenesis of major affective disorder, both unipolar (recurrent major depression) and bipolar.(1) Modification of serotonergic neurotransmission is pivotally implicated in the mechanism of action of antidepressant drugs(2) and also in the action of mood stabilizing agents, particularly lithium carbonate.(3) Accordingly, genes that code for the multiple subtypes of serotonin receptors that have been cloned and are expressed in brain,(4) are strong candidates for a role in the genetic etiology of affective illness. We examined a structural variant of the serotonin 2C (5-HT2C) receptor gene (HTR2C) that gives rise to a cysteine to serine substitution in the N terminal extracellular domain of the receptor protein (cys23ser),(5) in 513 patients with recurrent major depression (MDD-R), 649 patients with bipolar (BP) affective disorder and 901 normal controls. The subjects were drawn from nine European countries participating in the European Collaborative Project on Affective Disorders. There was significant variation in the frequency of the HT2CR ser23 allele among the 10 population groups included in the sample (from 24.6% in Greek control subjects to 9.2% in Scots, chi(2) = 20.9, df 9, P = 0.01). Logistic regression analysis demonstrated that over and above this inter-population variability, there was a significant excess of HT2CR ser23 allele carriers in patients compared to normal controls that was demonstrable for both the MDD (chi(2) = 7.34, df 1, P = 0.006) and BP (chi(2) = 5.45, df 1, P = 0.02) patients. These findings support a possible role for genetically based structural variation in 5-HT2C receptors in the pathogenesis of major affective disorder.

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.

Tryptophan hydroxylase polymorphism and suicidality in unipolar and bipolar affective disorders: a multicenter association study

BACKGROUND

Being the rate-limiting enzyme in the biosynthesis of serotonin, the tryptophan hydroxylase gene (TPH) has been considered a possible candidate gene in bipolar and unipolar affective disorders (BPAD and UPAD). Several studies have investigated the possible role of TPH polymorphisms in affective disorders and suicidal behavior.

METHODS

The TPH A218C polymorphism has been investigated in 927 patients (527 BPAD and 400 UPAD) and their matched healthy control subjects collected within the European Collaborative Project on Affective Disorders.

RESULTS

No difference of genotype distribution or allele distribution was found in BPAD or UPAD. No statistically significant difference was observed for allele frequency and genotypes counts. In a genotype per genotype analysis in UPAD patients with a personal history of suicide attempt, the frequency of the C-C genotype (homozygosity for the short allele) was lower in UPAD patients (24%) than in control subjects (43%) (chi(2) = 4.67, p =.03). There was no difference in allele or genotype frequency between patients presenting violent suicidal behavior (n = 48) and their matched control subjects.

CONCLUSIONS

We failed to detect an association between the A218C polymorphism of the TPH gene and BPAD and UPAD in a large European sample. Homozygosity for the short allele is significantly less frequent in a subgroup of UPAD patients with a history of suicide attempt than in control subjects.

Impact of clinical variables on illness time course in mood disorders

The aim of this study is to investigate possible clinical predictors of the long-term outcome of mood disorders. We undertook a retrospective assessment of 426 inpatients affected by major depressive disorder (n=182) and bipolar disorder (n=244), with at least two episodes of illness alternating with complete recovery; subjects were affected for an average of 14.43+/-11.34 years and presented an average of 4.4+/-2.1 episodes. Random regression model analysis (http://www.uic.eu/hedeker/mix.html) was used to investigate the longitudinal time course of the illness. A progressive cycle shortening was observed, whereby the more episodes a subject experienced, the shorter the interval was between episodes, up to a plateau frequency of one episode/year on average. Bipolar diagnosis was the strongest predictive factor toward high frequency of episodes; a manic onset among bipolars was associated with an even worse outcome. Gender, education level, family history, duration of the first interval, severity of the first episode, lifetime mean severity and lifetime mean treatment level were not associated with outcome in terms of episode frequency. Our results suggest that recurrent affective disorders recruited in a clinical setting have a marked deteriorating mean time course.

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.

Linkage of mood disorders with D2, D3 and TH genes: a multicenter study

BACKGROUND

It has been suggested that the dopaminergic system is involved in the pathophysiology of mood disorders. We conducted a multicenter study of families with mood disorders, to investigate a possible linkage with genes coding for dopamine receptor D2, dopamine receptor D3 and tyrosine hydroxylase (TH).

METHODS

Twenty three mood disorder pedigrees collected within the framework of the European Collaborative Project on Affective Disorders were analyzed with parametric and non-parametric linkage methods. Various potential phenotypes were considered, from a narrow (only bipolar as affected) to a broad (bipolar+major depressive+schizoaffective disorders) definition of affection status.

RESULTS

Parametric analyses excluded linkage for all the candidate genes, even though small positive LOD (Limit of Detection) scores were observed for TH in three families. Non-parametric analyses yielded negative results for all markers.

CONCLUSION

The D2 and D3 dopamine receptors were, therefore, not a major liability factor for mood disorders in our sample, whereas TH may play a role in a subgroup of patients.

Serotonin receptor 2A, 2C, 1A genes and response to lithium prophylaxis in mood disorders

The aim of this study was to investigate the influence of serotonin receptors 2A, 2C and 1A gene variants on lithium prophylactic efficacy in mood disorders. One hundred and twenty-four subjects affected by bipolar (n=102) and major depressive (n=22) disorder were followed prospectively for an average of 52 months and were typed for 5-HT2A (T102C: n=111, HTP: n=104), 5-HT2C (n=110) and 5-HT1A (n=61) variants. Both 5-HT2A and 5-HT2C variants were not associated with lithium outcome. Consideration of possible stratification effects like gender, polarity, family history, age at onset and duration of lithium treatment did not influence results. No 5-HT1A gene variant was identified. 5-HT2A and 2C variants are not, therefore, associated with lithium prophylactic efficacy in mood disorders.

Tyrosine hydroxylase polymorphism and phenotypic heterogeneity in bipolar affective disorder: a multicenter association study

Tyrosine hydroxylase (TH), the rate-limiting enzyme in the metabolism of catecholamines, is considered a candidate gene in bipolar affective disorder (BPAD) and has been the subject of numerous linkage and association studies. Taken together, most results do not support a major gene effect for the TH gene in BPAD. Genetic and phenotypic heterogeneity may partially explain the difficulty of confirming the exact role of this gene using both association and linkage methods. Four hundred one BPAD patients and 401 unrelated matched controls were recruited within a European collaborative project (BIOMED1 project in the area of brain research, European Community grant number CT 92-1217, project leader: J. Mendlewicz) involving 14 centers for a case-control association study with a tetranucleotide polymorphism in the TH gene. Patients and controls were carefully matched for geographical origin. Phenotypic heterogeneity was considered and subgroup analyses were performed with relevant variables: age at onset, family history, and diagnostic stability. No association was observed in the total sample or for subgroups according to age at onset (n = 172), family history alone (n = 159), or high degree of diagnostic stability and a positive family history (n = 131). The results of this association study do not confirm the possible implication of TH polymorphism in the susceptibility to BPAD.

Tryptophan hydroxylase gene and response to lithium prophylaxis in mood disorders

Lithium is an effective prophylactic agent in mood disorders but not all patients with mood disorders respond to lithium therapy; it is therefore necessary to identify responders prior to treatment. Clinical predictors account for about half of the variance and it is probable that genetic factors play a substantial role. The aim of this study was to investigate the possible association between the tryptophan hydroxylase (TPH) gene and prophylactic efficacy of lithium in mood disorders. One hundred and eight subjects affected by bipolar (n = 90) and major depressive (n = 18) disorder were followed prospectively for an average of 50.4 months and were typed for their TPH variant using polymerase chain reaction techniques. TPH variants were marginally associated with lithium outcome (F = 3.16; d.f.=2,105; P = 0.046). Subjects with the TPH*A/A variant showed a trend toward a worse response compared to both TPH*A/C and TPH*C/C variants. Consideration of possible stratification effects such as gender, polarity or age at onset did not influence the observed association. TPH variants may be a possible factor influencing the prophylactic efficacy of lithium in mood disorders.

Dopamine receptor D2 and D4 genes, GABA(A) alpha-1 subunit genes and response to lithium prophylaxis in mood disorders

Lithium is an effective prophylactic agent in mood disorders, and genetic factors are likely to modulate individual susceptibility to lithium treatment. The aim of this study is to investigate the influence of dopamine receptor D2 (DRD2), D4 exon 3 (DRD4), and gamma-aminobutyric acid type A (GABA(A)) receptor alpha-1 subunit (GABRA1) gene variants on the efficacy of lithium prophylaxis in mood disorders. Patients with mood disorders (N = 125: bipolar subtype, n = 100; major depressive disorder subtype, n = 25) were followed prospectively for an average of 53 months and were typed for DRD2 (Ser311/Cys311: n = 121, VNTR: n = 63), DRD4 (n = 125) and GABRA1 (n = 61) variants using polymerase chain reaction (PCR) techniques. DRD2, DRD4 and GABRA1 variants were not associated with response to lithium. A trend was observed toward a better outcome of DRD4* 2/4 subjects, but it was due to only two subjects. Consideration of possible stratification effects like gender, polarity, family history, age at onset and duration of lithium treatment did not reveal any association either. DRD2, DRD4 and GABRA1 variants therefore do not appear to be associated with the outcome of lithium prophylaxis in mood disorders.

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.

Social adjustment and self-esteem in remitted patients with mood disorders

Mood disorders are characterized by manic and depressive episodes alternating with normal mood. While social function is heavily impaired during episodes of illness, there are conflicting opinions about inter-episode function. The present paper focuses on self-esteem and social adjustment in remitted mood disorders patients. Patients with mood disorders (99 bipolar and 86 major depressive subjects, in remission) were compared with a group of 100 control subjects. The self-esteem scale (SES) and the social adjustment scale (SAS) were used to measure self-esteem and social adjustment, respectively, in both groups of subjects. Patients with mood disorder exhibited worse social adjustment and lower self-esteem than control subjects. These results strongly confirm previous observations of poor inter-episode function in patients with mooddisorder.

Self-esteem in remitted patients with mood disorders is not associated with the dopamine receptor D4 and the serotonin transporter genes

Disturbances of the dopaminergic and serotoninergic neurotransmitter systems have been implicated in the pathogenesis of depressive symptoms. Associations have been reported between markers of the two neurotransmitter systems and the presence of illness or severity of depressive episodes, but no attention has been focused on the periods of remission. The present report focuses on a possible association of self-esteem in remitted mood disorder patients with the functional polymorphism located in the upstream regulatory region of the serotonin transporter gene (5-HTTLPR) and the dopamine receptor D4 (DRD4). Inpatients (N=162) affected by bipolar (n=103) and unipolar (n=59) disorder (DSM III-R) were assessed by the Self-Esteem Scale (SES, Rosenberg, 1965) and were typed for DRD4 and 5-HTTLPR (n=58 subjects) variants at the third exon using polymerase chain reaction (PCR) techniques. Neither DRD4 nor 5-HTTLPR variants were associated with SES scores, and consideration of possible stratification effects such as sex and psychiatric diagnosis did not reveal any association either. The serotonin transporter and dopamine receptor D4 genes do not, therefore, influence self-esteem in remitted mood disorder subjects.