Forgetting the name of the person you met a week ago or where you left your wallet over the weekend could soon be something that's actually treatable with a "memory drug."

New studies by researchers in Japan have found that a dose of histamine may help improve long-term memory, defined as remembering objects from more than 48 hours prior.

Over three dozen people in their mid-20s completed memory tests on a computer in which they were shown objects like glasses or a watch and then returned several days later to see if they could recall what images they had been shown previously. 

When they returned they were either given a placebo pill or a dose of a drug that increases the amount of histamine in the brain. Those participants that had a hard time remembering were able to recall more images correctly after taking the drug. Also, images that were difficult to recall for even those with relatively good memories also became easier to remember.

But there is a rather significant catch to what may seem like a miracle memory drug treatment.

The pro-histamine treatment actually lowered scores of study participants with relatively good memories and easy to recall images became slightly harder for all the subjects to recollect.

Professor Yuji Ikegaya of the University of Tokyo, one of the research leaders, thinks what might be going on is that memories are stored but sometimes the nerves in the brain don't always fire to allow us to recall them until some kind of threshold is reached.

"You still have the memory, but you can't access it unless it is above a particular threshold," said Ikegaya.

Some memories reach that threshold easily and we remember, while others do not. Ikegaya says it seems that histamine may help reach that threshold for some hard-to-access memories. However, the effect also seems to work in reverse. Histamine may block the threshold from being reached for memories that would normally be easy to remember. 

It could be that memory is not as simple as remembering or forgetting things, with remembering always being positive and forgetting always negative. Forgetting sad or traumatic memories may be beneficial for some processes in the mind and body.

"If we have typical memory, then there is a balance between the brain systems for remembering and for forgetting. Too much forgetting or too much remembering is likely an upset of that balance," said Ikegaya.

He adds one final warning to anyone thinking they're ready to get their hands on some pro-histamines to get a memory edge:

"To any students thinking about using this drug as a study aid, I must warn them to first always protect their health, and second to realize that we have not tested whether this drug helps anyone learn or memorize new things."

The research is published in the latest issue of the journal Biological Psychiatry.

More research is planned for the investigating the effects of histamine on memory. Specifically, the researchers are looking at potential impacts for older adults and for "prospective memory," which includes the type of things we actively want to remember; the type of things we might write on a sticky note at our desk.

Or put another way, the kind of thing you might be willing to take a memory pill for.