Holt-Lunstad J, Smith TB, Layton JB. Social Relationships and Mortality Risk: A Meta-analytic Review. PLoS Medicine, 2010; 7 (7):

The experimental task was to watch a 10-minute video clip of a Scarborough shopping district , and participants had to remember a series of instructions which they then had to carry out when they saw specified locations.

So what happened? The binge drinkers did far worse than the non-binging students, recalling significantly fewer combinations of location-action/items. This form of recall linking an action to a point in the future is known as prospective memory, for example remembering to go to a doctor’s appointment.

Research team leader Heffernan points out that so far there is no known “safe” level for teenagers’ drinking, and that possibly excessive drinking might interfere with the neuro-cognitive development of the teenage brain. This research adds to the evidence which is mounting up that because teenage brains are still maturing and undergoing significant development in terms of structure and function they could be seriously affected by environmental factors such as alcohol binges. However, one fact which has come out of this research is that self-reports showed that binging participants did not think their own memory functioned poorly, suggesting that they are unaware of the damage being caused.

So maybe if you do have your own lucky mascot it could be a good idea to keep it by you when you are competing or doing exams.

Good luck!

* from old stuffed animals, and stones to wedding rings

That experiment was adapted from one using fruit smoothies where participants were shown either a small or a large portion of fruit ‘used’ to make their smoothie. Their perception of satiety was directly linked to their perception of the quantity of fruit seen.

These findings, if reliable and valid, have real implications. When we consume a diet drink or food, or a reduced calorie or reduced sugar/fat food, does this affect how we feel afterwaards?  Do we feel hungry again much sooner because of our perception? If this is so, then using different descriptions might have a beneficial effect on those people who are trying to lose weight. One famous firm has for some time been marketing ‘hearty’ soups – this may have been a very smart move!

Now research suggests that many depressed people really do eat more chocolate. These findings came from both men and women who scored high on a psychometric depression scale but who were not receiving medication. There were no reported increases in other antioxident-rich foods, or other sources of caffeine, fat or sugar, between these depressed adults and non-depressed adults, just the increased chocolate consumption. What is not known is why the chocolate intake increased.

The evolutionary hypothesis explains our liking of chocolate as a combination of pleasures – the sweetness, the creamy texture in the mouth perhaps in some way reminiscent of breast milk – with the high energy-denseness of this food. But there is a complete lack of evidence that breast milk, even in mothers who do eat a lot of chocolate, has any chocolate flavour! So this does not explain why consumption of chocolate rather than any other sweet and creamy food increased in depressed people. Is it the pleasure which is the key factor? Or is it the cultural perception of chocolate as a reward food? Or is there another reason?

*PO=prolyl oligopeptidase

A recent interesting finding in rats shows that females are definitely more sensitive to stress. Their brain cells respond far more strongly to the precursor to corticosteroid stress hormones, a neurochemical called corticotropin-releasing factor, CRF. Female rat neurons are activated by CRF, male rat neurons adapt to it and less stress hormones are produced.

But does this rat behaviour also happen in humans? Well, we don’t know; but we do know that CRF regulation gets disrupted in human stress-related psychological disorders, so there could be a similarity, although one needs always to be very careful in generalising between species.

There were small improvements in physical health but greater improvements were found in mental states. Improvements in anxiety and depression from exercise were greater than similar improvements in standard care without an exercise component.

These studies support the findings of two earlier studies, which suggests the importance of further research into the effects of exercise programmes in the treatment of schizophrenia plus initiatives looking into how to implement such programmes and engage sufferers in taking part.