Effect of affective temperament on illness characteristics of subjects with bipolar disorder and major depressive disorder

BACKGROUND

Affective temperaments represent the stable, biologically determined substrates of mood disorders. The relationship between affective temperaments and bipolar disorder (BD) or major depressive disorder (MDD) has been described. However, the strength of such relationship should be tested while considering other factors influencing the diagnosis of BD/MDD. Literature also lacks a comprehensive description of the interplay between affective temperament and characteristics of mood disorders. The aim of the present study is to address these issues.

METHODS

This is a multicentric observational study including 7 Italian university sites. Five-hundred-fifty-five euthymic subjects with BD/MDD were enrolled and further divided in those with hyperthymic (Hyper, N = 143), cyclothymic (Cyclo, N = 133), irritable (Irr, N = 49), dysthymic (Dysth, N = 155), and anxious (Anx N = 76) temperaments. Linear, binary, ordinal and logistic regressions were performed to assess the association between affective temperaments and i) diagnosis of BD/MDD; ii) characteristics of illness severity and course.

RESULTS

Hyper, Cyclo and Irr were more likely to be associated with BD, together with earlier age of onset and presence of a first-degree relative with BD. Anx and Dysth were more associated with MDD. Differences in association between affective temperaments and characteristics of BD/MDD were observed for hospital admissions, phase-related psychotic symptoms, length and type of depression, comorbidity and pharmacological intake.

LIMITATIONS

Small sample size, cross-sectional design, recall biases.

CONCLUSION

Specific affective temperaments were associated to certain characteristics of illness severity and course of BD or MDD. Evaluation of affective temperaments might help a deeper understanding of mood disorders.

High-resolution chromosome ideogram representation of recognized genes for bipolar disorder

Bipolar disorder (BPD) is genetically heterogeneous with a growing list of BPD associated genes reported in recent years resulting from increased genetic testing using advanced genetic technology, expanded genomic databases, and better awareness of the disorder. We compiled a master list of recognized susceptibility and genes associated with BPD identified from peer-reviewed medical literature sources using PubMed and by searching online databases, such as OMIM. Searched keywords were related to bipolar disorder and genetics. Our compiled list consisted of 290 genes with gene names arranged in alphabetical order in tabular form with source documents and their chromosome location and gene symbols plotted on high-resolution human chromosome ideograms. The identified genes impacted a broad range of biological pathways and processes including cellular signaling pathways particularly cAMP and calcium (e.g., CACNA1C, CAMK2A, CAMK2D, ADCY1, ADCY2); glutamatergic (e.g., GRIK1, GRM3, GRM7), dopaminergic (e.g., DRD2, DRD4, COMT, MAOA) and serotonergic (e.g., HTR1A, HTR2A, HTR3B) neurotransmission; molecular transporters (e.g., SLC39A3, SLC6A3, SLC8A1); and neuronal growth (e.g., BDNF, IGFBP1, NRG1, NRG3). The increasing prevalence of BPD calls for better understanding of the genetic etiology of this disorder and associations between the observed BPD phenotype and genes. Visual representation of genes for bipolar disorder becomes a tool enabling clinical and laboratory geneticists, genetic counselors, and other health care providers and researchers easy access to the location and distribution of currently recognized BPD associated genes. Our study may also help inform diagnosis and advance treatment developments for those affected with this disorder and improve genetic counseling for families.

Suicide risk in major affective disorder: results from a national survey in China

BACKGROUND

This study investigated suicide risk and its correlates among major affective disorder patients in China and examined possible risk factors for future suicide among individuals with major affective disorder to inform appropriate interventions and management approaches to minimize and prevent suicide.

METHODS

A total of 1478 major affective disorder patients were consecutively examined in 13 mental health centers in China. The patients' socio-demographic and clinical characteristics were recorded using a standardized protocol and data collection procedure. DSM-IV diagnoses were established using the Mini International Neuropsychiatric Interview (MINI), and suicide risk was assessed by the suicide risk module of the MINI.

RESULTS

Of the patients, 963 (65.2%) were in the nonsuicidal risk group and 515 (34.8%) were in the suicidal risk group. Compared to major depressive disorder patients, bipolar disorder patients had higher suicide risk levels (χ2=10.0, df=1, P=0.002); however, there were no statistically significant differences (χ2=2.6, df=1, P=0.1) between bipolar disorder-I and bipolar disorder-II patients. Suicide risk factors were associated with 6 variables in major affective disorder patients, as follows: male gender, unemployed, more frequent depressive episodes (>4 in the past year), depressive episodes with suicidal ideation and attempts, depressive episodes with psychotic symptoms, and no current antidepressant use.

LIMITATIONS

Most of the data were retrospectively collected and, therefore, subject to recall bias.

CONCLUSIONS

This study suggested that bipolar disorder patients have a higher suicide risk than major depressive disorder patients. The factors that were significantly associated with suicide risk may aid in identifying major affective disorder patients who are at risk for future suicidal behavior.