During depression, the brain becomes less plastic and adaptable, and thus less able to perform certain tasks, like storing memories. Researchers at the Swedish medical university Karolinska Institutet have now traced the brain’s lower plasticity to reduced functionality in its support cells, and believe that learning more about these cells can pave the way for radical new therapies for depression. “We were able to cure memory dysfunction in ‘depressed’ rats by giving them doses of D-serine,” says Mia Lindskog, biologist and Assistant Professor at Karolinska Institutet’s Department of Neuroscience.

Dr Lindskog and her team used FSL rats, which are rats that have been specially bred with a disposition for ‘depression’. The rats were first put through two tests to confirm that they had the symptoms that are also characteristic of human depression. In the first, the rats’ memories were checked by repeatedly being exposed to different objects; in the second, the team assessed their level of apathy by releasing them in a container of water and observing whether they merely stayed floating in the container or immediately tried to climb out (non of the rats had to stay in the water for more than five minutes). In both cases the FSL rats’ results were compared with normal laboratory rats, and memory disorders and apathy could be confirmed.

The researchers then injected the rats with D-serine. This substance improved their memories but had no effect on the apathy. “We have shown that there are two symptoms here that can be influenced independently of one another, which means they could be treated in tandem in patients with depression,” says Dr Lindskog. The researchers also studied the synaptic activity in the hippocampus of the rats, a part of the brain which plays an important part in the memory. [continue reading…]

Trying to make a big decision while you’re also preparing for a scary presentation? You might want to hold off on that. Feeling stressed changes how people weigh risk and reward. A new article published in Current Directions in Psychological Science, a journal of the Association for Psychological Science, reviews how, under stress, people pay more attention to the upside of a possible outcome.

It’s a bit surprising that stress makes people focus on the way things could go right, says Mara Mather of the University of Southern California, who cowrote the new review paper with Nichole R. Lighthall. “This is sort of not what people would think right off the bat,” Mather says. “Stress is usually associated with negative experiences, so you’d think, maybe I’m going to be more focused on the negative outcomes.”

But researchers have found that when people are put under stress—by being told to hold their hand in ice water for a few minutes, for example, or give a speech—they start paying more attention to positive information and discounting negative information. “Stress seems to help people learn from positive feedback and impairs their learning from negative feedback,” Mather says. [continue reading…]

Do antidepressants work? Since the introduction of Prozac in the 1980s, prescriptions for antidepressants have soared 400 percent, with 17 million Americans currently taking some form of the drug. But how much good is the medication itself doing? “The difference between the effect of a placebo and the effect of an antidepressant is minimal for most people,” says Harvard scientist Irving Kirsch. Will Kirsch’s research, and the work of others, change the $11.3 billion antidepressant industry? Lesley Stahl investigates. Read Story: Treating Depression: Is there a placebo effect?

Caution If you are depressed you should see your doctor. If you are already on Anti-depressants you should not stop taking them

Source: CBS News