Variation in GNB3 predicts response and adverse reactions to antidepressants.

There is substantial inter-individual variation in response and adverse reactions to antidepressants, and genetic variation may, in part, explain these differences. GNB3 encodes the ß3 subunit of the G protein complex, which is involved in the downstream signalling cascade following monoamine receptor activation. A functional polymorphism in this gene (C825T) has been associated with response to antidepressants. Several lines of evidence suggest that GNB3 moderates improvement in the neurovegetative symptoms of depression (such as sleep and appetite) and related adverse reactions independently of change in core mood symptoms. We here report analysis of data from GENDEP, a part-randomized pharmacogenomic trial, on the outcome of 811 subjects with major depression undergoing treatment with either escitalopram or nortriptyline in which the C825T SNP and three further SNPs in GNB3 were genotyped. The TT genotype was significantly associated with a superior response to nortriptyline and these effects were specific to improvements in neurovegetative symptoms. In addition, the same genotype predicted fewer incidents of treatment-emergent insomnia and greater weight gain on the same drug. Our results are consistent with previous associations with GNB3 and emphasize the importance of signalling genes in antidepressant response.

Utility of the pooling approach as applied to whole genome association scans with high-density Affymetrix microarrays.

BACKGROUND: We report an attempt to extend the previously successful approach of combining SNP (single nucleotide polymorphism) microarrays and DNA pooling (SNP-MaP) employing high-density microarrays. Whereas earlier studies employed a range of Affymetrix SNP microarrays comprising from 10 K to 500 K SNPs, this most recent investigation used the 6.0 chip which displays 906,600 SNP probes and 946,000 probes for the interrogation of CNVs (copy number variations). The genotyping assay using the Affymetrix SNP 6.0 array is highly demanding on sample quality due to the small feature size, low redundancy, and lack of mismatch probes. FINDINGS: In the first study published so far using this microarray on pooled DNA, we found that pooled cheek swab DNA could not accurately predict real allele frequencies of the samples that comprised the pools. In contrast, the allele frequency estimates using blood DNA pools were reasonable, although inferior compared to those obtained with previously employed Affymetrix microarrays. However, it might be possible to improve performance by developing improved analysis methods. CONCLUSIONS: Despite the decreasing costs of genome-wide individual genotyping, the pooling approach may have applications in very large-scale case-control association studies. In such cases, our study suggests that high-quality DNA preparations and lower density platforms should be preferred.

The Bipolar Association Case-Control Study (BACCS) and meta-analysis: No association with the 5,10-Methylenetetrahydrofolate reductase gene and bipolar disorder.

Bipolar disorder (BD) is a complex genetic disease for which the underlying pathophysiology has yet to be fully explained. 5,10-Methylenetetrahydrofolate reductase (MTHFR) is a crucial enzyme in folate-mediated one-carbon metabolism and folate deficiency can be associated with psychiatric symptoms. A single base variant in MTHFR gene (C677T) results in the production of a mildly dysfunctional thermolabile enzyme and has recently been implicated in BD. We conducted an association study of this polymorphism in 897 patients with bipolar I or bipolar II disorder, and 1,687 healthy control subjects. We found no evidence for genotypic or allelic association in this sample. We also performed a meta-analysis of our own, and all published data, and report no evidence for association. Our findings suggest that the MTHFR C677T polymorphism is not involved in the genetic etiology of clinically significant BD.

Suicidal ideation during treatment of depression with escitalopram and nortriptyline in genome-based therapeutic drugs for depression (GENDEP): a clinical trial.

BACKGROUND: Suicidal thoughts and behaviours during antidepressant treatment, especially during the first weeks of treatment, have prompted warnings by regulatory bodies. The aim of the present study is to investigate the course and predictors of emergence and worsening of suicidal ideation during tricyclic antidepressant and serotonin reuptake inhibitor treatment. METHODS: In a multicentre part-randomised open-label study, 811 adult patients with moderate to severe unipolar depression were allocated to flexible dosage of escitalopram or nortriptyline for 12 weeks. The suicidality items of three standard measures were integrated in a suicidal ideation score. Increases in this score were classified as treatment emergent suicidal ideation (TESI) or treatment worsening suicidal ideation (TWOSI) according to the absence or presence of suicidal ideation at baseline. RESULTS: Suicidal ideation decreased during antidepressant treatment. Rates of TESI and TWOSI peaked in the fifth week. Severity of depression predicted TESI and TWOSI. In men, nortriptyline was associated with a 9.8-fold and 2.4-fold increase in TESI and TWOSI compared to escitalopram, respectively. Retirement and history of suicide attempts predicted TWOSI. CONCLUSION: Increases in suicidal ideation were associated with depression severity and decreased during antidepressant treatment. In men, treatment with escitalopram is associated with lower risk of suicidal ideation compared to nortriptyline. Clinicians should remain alert to suicidal ideation beyond the initial weeks of antidepressant treatment. TRIAL REGISTRATION: EudraCT (No.2004-001723-38) and ISRCTN (No. 03693000).

A national survey of psychiatric mother and baby units in England.

OBJECTIVE: This study identified all mother and baby units (MBUs) (defined in this study as inpatient psychiatric units where mothers and babies could be admitted that had at least four beds and were separate from other wards) in England and established the operating procedures of MBUs and the clinical characteristics of their inpatients. METHODS: A national cross-sectional survey of alternatives to standard acute inpatient care was conducted in England in 2005. Multiple methods, including telephone inquiries and consultation with relevant experts, were used to identify services. All MBUs identified were contacted and invited to participate in an interview with a researcher. RESULTS: Twenty-six facilities that accommodated mothers and babies were identified. Thirteen were excluded from the final analysis, because they did not fulfill the study's operationalized criteria for a MBU. Twelve of the 13 facilities with an MBU agreed to participate. Nationally, MBUs had fewer beds than needed and marked geographical variation. Ward size ranged between four and 12 beds, average occupancy was 78%, and the mean length of stay was 56 days. On admission, 45% of women were experiencing psychotic symptoms, and 18% were detained compulsorily. A significant proportion of MBUs did not offer psychological treatments (42%). CONCLUSIONS: The provision of MBUs in England is inequitable, and the clinical and operating characteristics of these services are highly variable. However, this study demonstrated that MBUs are serving women with severe mental illness. If services are to expand and develop in the future, more qualitative and quantitative studies are required to identify the most effective components of MBUs and examine for whom the MBUs are most helpful.

Differential efficacy of escitalopram and nortriptyline on dimensional measures of depression.

BACKGROUND: Tricyclic antidepressants and serotonin reuptake inhibitors are considered to be equally effective, but differences may have been obscured by internally inconsistent measurement scales and inefficient statistical analyses. AIMS: To test the hypothesis that escitalopram and nortriptyline differ in their effects on observed mood, cognitive and neurovegetative symptoms of depression. METHOD: In a multicentre part-randomised open-label design (the Genome Based Therapeutic Drugs for Depression (GENDEP) study) 811 adults with moderate to severe unipolar depression were allocated to flexible dosage escitalopram or nortriptyline for 12 weeks. The weekly Montgomery-Asberg Depression Rating Scale, Hamilton Rating Scale for Depression, and Beck Depression Inventory were scored both conventionally and in a more novel way according to dimensions of observed mood, cognitive symptoms and neurovegetative symptoms. RESULTS: Mixed-effect linear regression showed no difference between escitalopram and nortriptyline on the three original scales, but symptom dimensions revealed drug-specific advantages. Observed mood and cognitive symptoms improved more with escitalopram than with nortriptyline. Neurovegetative symptoms improved more with nortriptyline than with escitalopram. CONCLUSIONS: The three symptom dimensions provided sensitive descriptors of differential antidepressant response and enabled identification of drug-specific effects.

Personality and the bipolar spectrum: normative and classification data for the Eysenck Personality Questionnaire-Revised.

BACKGROUND: Personality traits dispose individuals toward particular affective states and may therefore have an important role in the etiology of affective disorders in particular. Despite being one of the most widely used and well-researched personality instruments, few studies have studied bipolar spectrum disorders using the revised Eysenck Personality Questionnaire (EPQ-R) (Eysenck HJ, Eysenck SBG. The Eysenck Personality Questionnaire-Revised. Sevenoaks: UK; Hodder & Stoughton, 1992). METHODS: The EPQ-R was administered to 50 bipolar patients, 50 unipolar patients, and 50 controls matched on age and sex. Participants in clinical groups were euthymic, and participants in the control groups were screened for symptoms of depression. RESULTS: The EPQ-R scores were most effective at discriminating unipolar patients from controls, such that unipolar patients were higher on neuroticism and lower on extraversion. Bipolar patients showed a similar personality profile to, but were not clearly distinguished from, unipolar patients. CONCLUSIONS: This research provides preliminary normative data for the EPQ-R that complement previous theoretical and empirical work in this area and suggests the usefulness of this tool in a clinical setting.

Collaborative genome-wide association analysis supports a role for ANK3 and CACNA1C in bipolar disorder.

To identify susceptibility loci for bipolar disorder, we tested 1.8 million variants in 4,387 cases and 6,209 controls and identified a region of strong association (rs10994336, P = 9.1 x 10(-9)) in ANK3 (ankyrin G). We also found further support for the previously reported CACNA1C (alpha 1C subunit of the L-type voltage-gated calcium channel; combined P = 7.0 x 10(-8), rs1006737). Our results suggest that ion channelopathies may be involved in the pathogenesis of bipolar disorder.

The genetics of bipolar affective disorder.

PURPOSE OF REVIEW: Molecular genetic studies of bipolar affective disorder are beginning to show some positive and reproducible findings. The most relevant of these will be reviewed. RECENT FINDINGS: Obtaining consistent findings from whole genome scans has been hampered by small sample sizes and phenotypic heterogeneity. Recently, there have been concerted efforts to overcome these problems by combining data for meta-analysis. What has become increasingly clear is that several regions that are likely to contain genes contributing to bipolar affective disorder are also relevant to schizophrenia, a finding supported by recent twin data. Studies to date have implicated the D-amino acid oxidase activator complex (also known as G72/G30), disrupted in schizophrenia-1 and neuregulin, and have pointed to several promising linkage regions in which the genes have not yet been identified. In addition, there is some evidence to support the involvement of genetic variants in catechol-o-methyl transferase and brain-derived neurotrophic factor in the aetiology of bipolar affective disorder. SUMMARY: Molecular genetic research in bipolar affective disorder may lead to the development of new diagnostic paradigms for classifying the psychoses and affective states. In addition, determining the functional significance of the susceptibility genes will pave the way for enhanced diagnostic accuracy and improved treatments.

Association between dopamine D3 receptor gene polymorphisms and schizophrenia in an isolate population.

There are several lines of evidence implicating the dopamine D3 receptor in the pathophysiology of schizophrenia. The Ser9Gly polymorphism of the dopamine D3 receptor gene (DRD3) has been the most extensively investigated DRD3 variant in connection with the disease but results have been inconclusive. Recent reports indicate that the Ser9Gly polymorphism is in linkage disequilibrium with other markers, but association studies between DRD3 haplotypes and schizophrenia have had mixed results. Genetic heterogeneity may be one of the causes of contradicting results. In order to clarify the role of DRD3 alterations in the aetiology of disease, we have investigated three D3 genetic variants (Ser9Gly, -205-G/A, -7685-G/C) in a sample of patients with schizophrenia or schizoaffective disorder (N=118) and controls (N=162) recruited from a human isolate from Navarra (Northern Spain) of Basque origin. Although no association was found between the Ser9Gly or the -205-A/G polymorphisms and disease, an excess of allele -7685-C was observed in patients (p=0.002 after correction for multiple analyses). Haplotype analysis shows the three markers to be in strong linkage disequilibrium (p<0.0001) and strongly associated with disease (p<1x 10(-5)). These results may suggest that these polymorphisms exert a combined or synergistic effect on susceptibility to schizophrenia, or are in linkage with an unknown causative factor. However, further replication in independent samples is required.