basal ganglia and bipolar depression

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(http://www.medwire-news.md/news/article.aspx?k=55 & d=2006-05-15) | _08 May_ (http://www.medwire-news.md/news/article.aspx?k=55 & d=2006-05-08) | _01 May_ (http://www.medwire-news.md/news/article.aspx?k=55 & d=2006-05-01) | _24 Apr_ (http://www.medwire-news.md/news/article.aspx?k=55 & d=2006-04-24) | _Archive_ (http://www.medwire-news.md/news/article.aspx?k=55 & d=archive) Basal ganglia plays role in bipolar depression11 May

2006J Affect Disord 2006; 91: 235-242 Researchers have found evidence to support the involvement of the basal ganglia in bipolar disorder and depressive illness. They found that the globus pallidus was less responsive during a simple motor task in bipolar patients in depressed states compared with when they were in normal or euthymic states. Caligiuri (University of California at San Diego, USA) and colleagues believe this effect may underlie the clinical manifestations of depression in patients with bipolar disorder. The investigators carried out functional magnetic resonance imaging on 10 patients with bipolar disorder. Using a simple motor reaction time task, they were able to monitor activity in the subcortical regions bilaterally. The participants were scanned on two occasions, once when their self-reported mood ratings indicated hypomania or euthymia and then again

when they were in depressed states. When patients were in their euthymic or hypomanic states, they exhibited increased activity in the head of the caudate nucleus bilaterally and the left globus pallidus. In contrast, patients in depressed states showed decreased activity in the external segment of the right globus pallidus. Patients taking antidepressants exhibited greater activation in the thalamus, external globus pallidus, and caudate than those not taking antidepressants. Conversely, patients taking antipsychotics when in depressed states exhibited less activation in thalamus, putamen, both segments of the globus pallidus, and caudate, than those not taking such drugs. "These results are consistent with current physiologic models of basal ganglia circuitry in which an increase in caudate activity results in an increase in inhibitory gamma-aminobutyric acid (GABA)ergic

outflow to the external globus pallidus and subsequent decrease in thalamocortical excitation," the researchers explain. "Reduced thalamocortical excitation may underlie the behavioral changes observed in depression, such as slowed movement, reduced energy, diminished appetite, anhedonia, slowed thinking and speech, and depressed mood," they conclude. _Free abstract _ (http://www.jad-journal.com/article/PIIS0165032706000346/abstract?browse_volume=91 & issue_key=TOC@@JOURNALSNOSUPP@JAD@0091@0002 & issue_preview=no & select1=no & select1=no & vol) ________________________________________________________________________________________________________________________________________________Message 2 From: "Jackel669@..." Jackel669@... Date: Tue May 16, 2006 6:37am(PDT) Subject: Check out MedWire News - News_Click here: MedWire News - News_ (http://www.medwire-news.md/news/article.aspx?k=56 & id=56829) _http://www.medwire-news.md/news/article.aspx?k=56 & id=56829_ (http://www.medwire-news.md/news/article.aspx?k=56 & id=56829) Weekly service, published on Mondays, offering news on every aspect of depression,

from screening and predictive factors to disease recognition, treatment, and management of the condition. _15 May_ (http://www.medwire-news.md/news/article.aspx?k=56 & d=2006-05-15) | _08 May_ (http://www.medwire-news.md/news/article.aspx?k=56 & d=2006-05-08) | _01 May_ (http://www.medwire-news.md/news/article.aspx?k=56 & d=2006-05-01) | _24 Apr_ (http://www.medwire-news.md/news/article.aspx?k=56 & d=2006-04-24) | _17 Apr_ (http://www.medwire-news.md/news/article.aspx?k=56 & d=2006-04-17) | _Archive_ (http://www.medwire-news.md/news/article.aspx?k=56 & d=archive) Acute stress 'predominant depression risk factor for high-risk individuals'15 May 2006J Affect Disord 2006; 91: 195–203 Researchers have found that risk factors for depression differ between people who have a familial risk for affective disorders and individuals from the general population. Tobias Drieling and colleagues from the University of Freiburg in Germany report that patients at increased risk of depression due to having a family member with an affective disorder are more sensitive to the depressogenic effects of acute stress, whereas depression in others is associated with persistent factors such as personality and

chronic difficulties. The researchers looked for risk factors for depressive disorders over a period of 6.5 years in 89 high-risk individuals who had siblings or parents with an affective disorder and 49 controls without any personal or family history of affective disorders. Assessments showed that neurotic traits, including neuroticism and frustration intolerance, were associated with depressive symptoms at the end of the study for both groups. However, when the sub-traits were looked at individually, neuroticism – reflecting a more general emotional instability – was a risk factor predominantly in controls. In contrast, low frustration tolerance, which represents mainly high stress reactivity, turned out to be a risk factor for subsequent depressive symptoms mainly for high-risk individuals. The broadly defined personality trait "melancholic type" was not a risk factor for

depression in either group. But the sub-trait of rigidity, which describes high consciousness, perfectionism, and orderliness, was a more specific predictor of depression, but only in controls. For the high-risk group, acute adverse life events were a strong predictor of depression, whereas they had no predictive value in controls. Rather, controls tended to be affected by more chronic difficulties. Despite having less stressful life events as controls and the same risk for chronic difficulties, adverse events were perceived by the high-risk individuals as being more stressful. "The most important risk factors in high-risk subjects appear to be of a more acute nature such as acute life events or personality traits like frustration intolerance that impair the ability to cope with acute stressors," say Drieling et al in the Journal of Affective Disorders. "High-risk subjects may thus be more

vulnerable for depression, because their coping with acute adverse life events is compromised," they explain. "They may therefore avoid adverse life events to a higher extent as compared to controls and perceive adverse events as more burdening." _Free abstract _ (http://www.jad-journal.com/article/PIIS016503270600005X/abstract?browse_volume=91 & issue_key=TOC@@JOURNALS@JAD@0091@0002 & issue_preview=no & select1=no & select1=no & vol)

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