Differential Impact of a Complex Environment on Positive Affect in an Animal Model of Individual Differences in Emotionality.

Differential impact of a complex environment on positive affect in an animal model of individual differences in emotionality.

Neuroscience. 2013 Jun 24;
Perez-Sepulveda JA, Flagel SB, Garcia-Fuster MJ, Slusky RJ, Wayne Aldridge J, Watson S, Akil H

Anhedonia, or the inability to experience positive feelings is a hallmark of depression. However, few animal models have relied on decreased positive affect as an index of susceptibility to depression. Rats emit frequency modulated ultrasonic vocalizations (USVs), designated as “positive” calls in the 50kHz range. USVs have been associated with pharmacological activation of motivational reward circuits. Here we utilized selectively-bred rats differing in “emotionality” to ask whether there are associated differences in USVs. Rats bred based on locomotor response to novelty and classified as bred high-responders (bHRs) or bred low-responder (bLRs) exhibit inborn differences in response to environmental cues, stress responsiveness, and depression-like behavior. These animals also exhibit differences in anxiety-like behavior, which are reversed by exposure to environmental complexity (EC). Finally, these animals exhibit unique profiles of responsiveness to rewarding stimuli accompanied with distinct patterns of dopamine regulation. We investigated whether acute and chronic environmental manipulations impacted USVs in bHRs and bLRs. We found that, relative to bLRs, bHRs emitted significantly more 50 kHz USVs. However, if a bLR is accompanied by another bLR, there is a significant increase in 50kHZ USVs emitted by this phenotype. bHRs emitted increases in 50kHZ UVSs upon first exposure to EC, whereas bLRs showed a similar increase only after repeated exposure. bLRs’ increase in positive affect after chronic EC was coupled with significant positive correlations between corticosterone levels and c-fos mRNA in the accumbens. Conversely, a decline in the rate of positive calls in bHRs after chronic EC was associated with a negative correlation between corticosterone and accumbens c-fos mRNA. These studies demonstrate that inborn differences in emotionality interact with the environment to influence positive affect and underscore the potential interaction between glucocorticoids and the mesolimbic reward circuitry in modulating 50 kHz calls. HubMed – depression


Loneliness Among Older Veterans in the United States: Results from the National Health and Resilience in Veterans Study.

Am J Geriatr Psychiatry. 2013 Jun 25;
Kuwert P, Knaevelsrud C, Pietrzak RH

This study examined the current prevalence, and demographic, military, health, and psychosocial correlates of loneliness in a contemporary nationally representative sample of older U.S. veterans.Two thousand twenty-five veterans aged 60 years and older participated in the National Health and Resilience in Veterans Study. Loneliness was assessed using a questionnaire adapted from the Revised UCLA Loneliness Scale. A broad range of demographic, military, health, and psychosocial variables was also assessed.44% of veterans reported feeling lonely at least some of the time (10.4% reported often feeling lonely). Greater age, disability in activities of daily living, lifetime traumas, perceived stress, and current depressive and post-traumatic stress disorder symptoms were positively associated with loneliness, and being married/cohabitating, higher income, greater subjective cognitive functioning, social support, secure attachment, dispositional gratitude, and frequency of attending religious services were negatively associated with loneliness. The largest magnitude associations were observed for perceived social support, secure attachment style, and depressive symptoms.Loneliness is prevalent among older veterans in the United States, and associated with several health and psychosocial variables. These results suggest that multifactorial interventions that emphasize bolstering of social support and reduction of depressive symptoms may help mitigate loneliness in the rapidly growing population of older veterans. HubMed – depression


Dietary patterns and anthropometric indices among Iranian women with major depressive disorder.

Psychiatry Res. 2013 Jun 24;
Rashidkhani B, Pourghassem Gargari B, Ranjbar F, Zareiy S, Kargarnovin Z

Major depression is a common mental disorder among women. A number of studies have demonstrated the association between some nutrients and food items with depression, but the studies on the association of dietary patterns with depression, especially in the Middle East, are rare. Further, the literature examining the relationship between anthropometric status and depression are inconsistent. In this study, 45 women with major depression and 90 patients with no mental disorder participated. We collected dietary intakes by a semi-quantitative food frequency questionnaire, and measured anthropometric indices (weight, height, waist and hip circumferences). Using factor analysis, two major dietary patterns were extracted: Healthy and Unhealthy. After adjusting for confounders, individuals who gained higher scores in healthy dietary pattern, had 84% lower odds of major depression; while the odds of major depression in participants who gained higher scores in unhealthy dietary pattern showed no significant association. No significant association was found between anthropometric indices and major depression. These results suggest that the healthy dietary pattern is significantly associated with lower odds of major depression in adult women. Further researches are needed to confirm these findings. HubMed – depression