While depression is often linked to negative thoughts and emotions, a new study suggests the real problem may be a failure to appreciate positive experiences.

Researchers at Ohio State University found that depressed and non-depressed people were about equal in their ability to learn negative information that was presented to them.

But depressed people weren't nearly as successful at learning positive information as were their non-depressed counterparts.

"Since depression is characterized by negative thinking, it is easy to assume that depressed people learn the negative lessons of life better than non-depressed people - but that's not true," said Laren Conklin, co-author of the study and a graduate student in psychology at Ohio State.

The study appears in the March issue of the Journal of Behavior Therapy and Experimental Psychiatry.

Researchers tested 34 college students, 17 of whom met criteria for clinical depression and 17 of whom were not depressed.

This study is one of the first to be able to link clinical levels of depression to how people form attitudes when they encounter new events or information, said Daniel Strunk, co-author of the study and assistant professor of psychology at Ohio State.

Strunk said the key to conducting this study was the use of a computer game paradigm co-developed at Ohio State in 2004 by Russell Fazio, a professor of psychology and co-author of this new study. Fazio and his collaborators, Natalie Shook, a PhD graduate of Ohio State now at Virginia Commonwealth University and J. Richard Eiser of the University of Sheffield (England) have used the game in many studies examining differences in the development of positive and negative attitudes.

The developers affectionately call the game "BeanFest." It involves people encountering images of beans on the computer screen. The beans could be good or bad, depending on their shape and the number of speckles they had.

Good beans earned the players points, while bad beans took points away. The goal was to earn as many points as possible.

While the game may seem trivial to a naive audience, Strunk said it offers a unique and powerful way to measure how people learn new attitudes.

"Before, if researchers wanted to investigate how people formed new attitudes, it was very difficult to do," Strunk said. If researchers asked about real-life issues, the problem is that prior learning and attitudes may impact how people respond to new information. But in this game, participants don't have any prior knowledge or attitudes about the beans so researchers could learn how they formed their attitudes in a novel situation, without interference from past experiences.

In the game phase of this study, participants had to choose whether they would accept a bean when it appeared on the screen. If they accepted the bean, the points were added or deducted from their total. If they rejected the bean, they were still told how many points they would have earned or lost if they had accepted it.

Each of the 34 beans was shown three times during the game phase, giving the participants a good opportunity to learn which beans were good and which were bad.

Then, in the test phase, participants had to indicate whether beans they learned about in the game phase were "good" (choosing it would increase points) or "bad" (choosing it would decrease points). The researchers tallied how well participants did in correctly identifying positive and negative beans.

The non-depressed students correctly identified 61 percent of the negative beans, which was about the same as the depressed students, who correctly identified 66 percent of the "bad" beans.

But while the non-depressed students correctly identified 60 percent of the positive beans, depressed students correctly classified only 49 percent of these good beans. Non-depressed students identified the good beans better than the depressed students, who failed to identify good beans better than chance.

"The depressed people showed a bias against learning positive information although they had no trouble learning the negative," Strunk said.

One of measures researchers used in the study classified whether the depressed participants were currently undergoing a mild, moderate or severe episode of depression. In the study, those undergoing a severe depressive episode did more poorly on correctly choosing positive beans than those with mild depression, further strengthening the results.

While more research is needed, Conklin and Strunk said this study suggests possible ways to improve treatment of depressed people.

"Depressed people may have a tendency to remember the negative experiences in a situation, but not remember the good things that happened," Conklin said. "Therapists need to be aware of that."

For example, a depressed person who is trying out a new exercise program may mention how it makes him feel sore and tired -but not consider the weight he has lost as a result of the exercise.

After having surgery for pancreatic cancer, obese people with a BMI of 35 or more seem to be the most likely to have poorer outcomes such as cancer that has spread to the lymph nodes, lower rates of survival and higher rates of cancer recurrence.

The study was the work of Dr Jason B Fleming, from the University of Texas MD Anderson Cancer Center in Houston, and colleagues and is published online in the March issue of the Archives of Surgery a Journal of the American Medical Association.

A person is classed as obese if their Body Mass Index (BMI, weight in kilos divided by the square of height in metres, kg/m2) is 30 or more. The "ideal" or normal range is 18.5 to 25: being outside of this range is linked to various health problems for underweight, overweight and obese people.

Rates of obesity have risen sharply in the US in the last 20 years, wrote the authors in their background information.

"In many obesity-related diseases and malignant neoplasms [cancerous tumors], an increased prevalence of pancreatic cancer has been reported in numerous epidemiologic and cohort studies focusing on obese patients," they wrote.

"Further, obesity has been associated with decreased survival in patients with pancreatic adenocarcinoma, although the mechanism remains unknown," they added.

For this study they wanted to examine the link between obesity, as measured by BMI, and medical outcomes and survival of patients who have had their pancreas removed to treat pancreatic adenocarcinoma.

The study looked at the results retrospectively (that is they found data relating to surgeries that had already taken place as opposed to setting up the study beforehand). The researchers looked at records from 285 consecutive patients whose BMI data was available and who had undergone "potentially curative pancreas resection to treat adenocarcinoma".

All the patients had attended a referral center with a dedicated multidisciplinary pancreas cancer program between 1 January 1999 and 31 October 2006.

In their statistical analysis the researchers looked for links between BMI and other prognostic information and the incidence of lymph nodes metastasis (how far the cancer had spread if it had), and survival rates.

The results showed that:

* Over the 16 month midpoint of the study (median follow up), 152 patients died (53 per cent).

* Patients whose BMI was over 35 survived a median of 13.2 months compared with 27.4 months for those whose BMI was under 23.

* At the last follow up, 15 of 20 patients (75 per cent) whose BMI was over 35 had died, compared with 137 of 265 patients (52 per cent) whose BMI was 35 or less.

* Cancer spreading to the lymph nodes was 12 times more likely in obese patients with BMI over 35 than in patients whose BMI was 35 and under.

* Disease-free and overall survival was also lower in patients whose BMI was above 35, and the risk of cancer recurrence and death after having their pancreas removed was nearly twice that of patients whose BMI was 35 and under.

The researchers concluded that:

"Obese patients with a BMI of more than 35 are more likely to have node-positive pancreatic cancer and decreased survival after surgical resection."

"Data suggest that the negative influence of BMI of more than 35 on cancer-related end points is unrelated to the potential complexity of performing major oncologic surgery in obese patients," they added.

Other studies have shown links between BMI over 35 and increased risk of death from pancreatic cancer, noted the authors, who wrote that:

"Our findings extend these observations to those patients who undergo surgery to treat pancreatic cancer and suggest that obesity is a host factor affecting tumor biology independent of the difficulties (patient- and treatment-related) involved in delivering oncologic care in obese patients."

"Future investigations should include a search for systemic or tumor biomarkers in this group of patients that could provide additional insight," they added.

Pregnant women who had untreated major depression in all three trimesters of pregnancy, as well as those who took certain antidepressants, had preterm birth rates exceeding 20 percent, according to a study by University of Pittsburgh School of Medicine researchers published in the March issue of American Journal of Psychiatry.

Approximately 10-to-20 percent of women struggle with symptoms of major depression during their pregnancies, but treating it can be complicated. Selective serotonin reuptake inhibitor (SSRI) antidepressants are usually the first line of depression treatment, but can lead to unwanted outcomes such as preterm births if used continuously throughout pregnancy, the findings suggest.

"It is well-known that the prevalence of depression in women is highest during the childbearing years, and treating the symptoms with SSRIs is a common medical therapy," said Katherine L. Wisner, M.D., M.S., director of the Women's Behavioral HealthCARE program at Western Psychiatric Institute and Clinic of UPMC, associate investigator at Magee-Womens Research Institute, and professor of psychiatry, obstetrics, gynecology and reproductive sciences and epidemiology at the University of Pittsburgh School of Medicine. "However, given the similarity in outcomes we found for continuous SSRI treatment and continuous depression, it is possible that underlying depressive disorder is a factor in preterm birth among women taking SSRIs."

Throughout this prospective study, researchers followed 238 women with no, partial, and continuous exposure to either depression or SSRI treatment during pregnancy and compared neonatal outcomes. They found that women exposed to either continuous SSRI treatment, or to continuous depression with no SSRI treatment, had comparable levels of increased risk for preterm birth at 21 percent and 23 percent, respectively. However, women with no exposure to either depression or SSRI medication had lower rates of preterm births, around 6 percent.

The researchers also discovered that either depression or SSRI treatment did not affect the baby's birth weight or the mother's weight gain during pregnancy or influence the rate of minor physical birth defects in the infant.

Previous studies have associated both depression and SSRIs with an increased risk for miscarriage. But taking these antidepressants during pregnancy does not greatly increase the overall risk of birth defects, noted Dr. Wisner.

While the results add more evidence linking SSRI treatment to risk of preterm birth, the risk of untreated depression conveys no less risk and suggests that factors independently related to both the disease and its treatment are associated with preterm birth.

"The relationship of preterm birth to depression and SSRI exposure must be clarified through further research," said Dr. Wisner. "In the meantime, it is recommended that each pregnant woman consult with her doctor to weigh the benefits and risks of depression treatment with antidepressants."

For 25 years, researchers have tried and failed to develop an HIV vaccine, primarily by focusing on a small number of engineered "super antibodies" to fend off the virus before it takes hold. So far, these magic bullet antibodies have proved impossible to produce in people. Now, in research published March 15 online by Nature, scientists at The Rockefeller University have laid out a new approach. They have identified a diverse team of antibodies in "slow-progressing" HIV patients whose coordinated pack hunting knocks down the virus just as well as their super-antibody cousins fighting solo.

By showcasing the dynamic, natural immune response in these exceptional patients, the research, led by Michel C. Nussenzweig, Sherman Fairchild Professor and head of the Laboratory of Molecular Immunology, suggests that an effective HIV vaccine may come from a shotgun approach using of a wide range of natural antibodies rather than an engineered magic bullet.

"We wanted to try something different, so we tried to reproduce what's in the patient. And what's in the patient is many different antibodies that individually have limited neutralizing abilities but together are quite powerful," says Nussenzweig, who also is a Howard Hughes Medical Institute investigator. "This should make people think about what an effective vaccine should look like."

HIV strains mutate rapidly, making them especially wily adversaries of the immune system. But one element is shared almost universally among the diverging strains - a protein on the envelope of the virus called gp140 that HIV needs to infect immune cells. Prior research has shown that four randomly engineered antibodies that block the activity of that protein prevent the virus from infecting immune cells in culture, but all attempts to coax the human body into producing those four have failed.

So Johannes Scheid, a visiting student in Nussenzweig's lab who is now a doctoral candidate, turned his attention to the antibodies produced by six people infected with HIV whose immune systems put up an exceptionally strong fight. The patients represent the roughly 10 to 20 percent of HIV patients who are able to control the virus and are very slow to progress to disease. Their immune systems' memory B cells produce high levels of antivirus antibodies, but until now, researchers have known little about the antibodies or how effective they are.

With help from Rockefeller's Center for Clinical and Translational Science and Rockefeller scientists David D. Ho and Jeffrey V. Ravetch, Scheid and colleagues isolated 433 antibodies from these individuals' blood serum that specifically targeted the envelope protein - the chink in HIV's protean armor. He cloned the antibodies and produced them in bulk, mapped which part of the envelope protein each targeted, and gauged how effective each was in neutralizing the virus. In the process, he identified a new structure within the envelope protein - called the gp120 core - that had never been recognized as a potential target for antibodies. "It's the first time that anyone has defined what is really happening in the B cell response in these patients," says Scheid.

It is more difficult to recognize and treat epilepsy in old than in young patients. In the new edition of Deutsches Ärzteblatt International (Dtsch Arztebl Int 2009; 106[9]: 135), Konrad J. Werhahn of the Epilepsy Center of Johannes Gutenberg University in Mainz, Germany, presents the clinical characteristics of the disease and the therapeutic options.

It is often not possible to recognize epileptic seizures unambiguously in older patients; they may be identified as confusion of unclear etiology, memory disturbance, or giddiness. Aura is a typical symptom in young patients, but is rare in old patients. Moreover, confusion after a seizure may last much longer in older patients with epilepsy, giving the impression of dementia or stroke.

Drug treatment of old patients with epilepsy is complicated. There has not yet been enough research on changes in drug distribution and decreased elimination through the liver and kidneys in epilepsy in the elderly. For this reason, many therapeutic decisions are based on experience with young epileptics, together with the knowledge of the general principles of pharmacotherapy in age. As old patients often require different drugs for a variety of diseases, drug interactions may occur. Moreover, older patients react more sensitively to drug side effects. The author discusses conventional antiepileptics, together with their side effects and interactions. Nevertheless, many questions cannot be answered with the current state of knowledge and the available studies.