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Background It was recently reported that an interaction of the dopamine D2 receptor (DRD2) and catechol-O-methyltransferase (COMT) influences the behavioural approach system – as measured using Carver and White's Behavioural Inhibition and Behavioural Approach System (BIS/BAS) scales – in a sample of healthy German subjects. The Temperament and Character Inventory (TCI), in particular the novelty seeking (NS) and harm avoidance (HA) scales, correlates moderately with the BIS/BAS measure. This study aimed to examine support for an association of DRD2 and COMT with behavioural activation, using the TCI within two independent samples of depressed outpatients (for both samples n = 146). Methods Two clinical samples of depressed patients were ascertained to assess the efficacy of two different pharmacotherapy and psychotherapy treatments. Analysis of variance (ANOVA) was used to analyse NS and HA scale and subscale scores with respect to gene loci within each clinical sample. Analysis of covariance were undertaken to examine the association of age and gender with NS and HA scores. An association of age group or gender with gene loci were explored using chi-squared tests, in each sample. Results No significant effect of DRD2 or COMT, either independently or as an interaction, on NS or HA scores was observed, within either sample. Whilst age was significantly negatively associated with NS scores, including age in the two- and three-way interactions did not affect the significance of the association of personality with gene loci. Conclusion This study suggests that the COMT-DRD2 Equilibrium Model of Positive Emotionality recently proposed by Reuter and his colleagues is not applicable amongst currently depressed individuals, whose behavioural approach and inhibition tendencies have been assessed using the TCI.

Background. There are few cross-national comparisons of the rates of suicide ideation and attempts across diverse countries. Nine independently conducted epidemiological surveys using similar diagnostic assessment and criteria provided an opportunity to obtain that data. Methods. Suicide ideation and attempts were assessed on the Diagnostic Interview Schedule in over 40000 subjects drawn from the United States, Canada, Puerto Rico, France, West Germany, Lebanon, Taiwan, Korea and New Zealand. Results. The lifetime prevalence rates/100 for suicide ideation ranged from 2·09 (Beirut) to 18·51 (Christchurch, New Zealand). Lifetime prevalence rates/100 for suicide attempts ranged from 0·72 (Beirut) to 5·93 (Puerto Rico). Females as compared to males had only marginally higher rates of suicidal ideation in most countries, reaching a two-fold increase in Taiwan. Females as compared to males had more consistently higher rates for suicide attempts, reaching a two- to three-fold increase in most countries. Suicide ideation and attempts in most countries were associated with being currently divorced/separated as compared to currently married. Conclusions. While the rates of suicide ideation varied widely by country, the rates of suicide attempts were more consistent across most countries. The variations were only partly explained by variation in rates of psychiatric disorders, divorce or separation among countries and are probably due to cultural features that we do not, as yet, understand.