My apologies, I thought that it was outside of the context of the conversation.

A surprisingly high percentage of people have nutritional deficiencies. For example, an alarmingly high percentage of people in the US are deficient in Magnesium, an essential nutrient (meaning that your body cannot manufacture it).

http://en.wikipedia.org/wiki/Magnesium_deficiency_%28medicin...

> 57% of the US population does not meet the US RDA for levels of magnesium

And we're talking about a first-world country here! Magnesium is essential for a healthy stress response, and, as we probably know from experience, many people struggle with the stresses of day to day life. Anybody who regularly consumes alcohol, tobacco or caffeine is likely to be deficient as those drugs rapidly deplete Mg reserves in the body.

That is just one example. Another is Calcium, which 75% of people have deficiency of (http://www.livestrong.com/article/365193-heart-disease-cause...).

The body also becomes less efficient as time goes on. Have you ever wondered by old people tend to be more grumpy than everybody else? Because our serotonin (a neurotransmitter which is implicated in mood and irritability) levels fall as we age - http://www.pslgroup.com/dg/4098E.htm

One way to offset the brain's natural decline of neurotransmitters is to supplement with the precursor amino acids which are used to manufacture those neurotransmitters. For example, L-Tryptophan, an essential (again, meaning that you cannot make it) amino acid is rapidly absorbed by the body and is used to make more serotonin (among other things). The difference between protein and straight amino acids is that the latter are ready for use, whereas proteins, which are composed of amino acids, need to be broken down to their constituent parts before the body can use them.

Another age-related neurotransmitter decline - dopamine. A lot of older people have had some success with using D,L-Phenylalanine and L-Tyrosine to boost dopamine levels and reclaim their sex drive.

Healthy acetylcholine levels are also essential for cognition and can be boosted with things containing Choline (eggs are an excellent source).

GABA levels are very important for short term memory and focus. For example, anyone who drinks coffee will have experienced that overexcited state where you have a mountain of motivation but lack proper focus. Taking L-Theanine (Green Tea also contains this), an amino acid which causes increases GABA levels will restore the focus. I never drink coffee without L-Theanine for this reason.

Taking L-Glutamine prior to drinking alcohol will prevent a hangover. It will also stop alcohol and sugar cravings. This is because the body is capable of using L-Glutamine as a source of energy.

But the most important thing is how all of these neurotransmitters interact with each other. Some of them are polar opposites, some modulate the release/inhibition of others. The brain is always striving for balance (homeostasis). All of these neurotransmitters, nutrients and minerals are vectors which pull it in one direction or another. Keeping them in balance is the key to feeling good. Having a model of their interactions makes it considerably easier to debug problems and fix them. This comes with experimenting with your body and gaining an intuitive understanding of what's what. I think that it would be difficult to come up with a generalised approach due to people's baseline levels of each neurotransmitter being different.

Note that even popular multivitamin brands sometimes contain too little of a given nutrient. I recently bought a doctor-recommended one and it barely contains and magnesium or calcium. It pays to educate yourself and not to completely defer your health to someone else. It's your body and it's essentially your problem.

After addressing deficiencies, I found that I felt a lot better and that my rate of recovery from stress, a night of drinking or strenuous physical activity had improved considerably.

Another important factor is removing things which cause harm. E.g. alcohol, in sufficiently high doses (high enough to be drunk), is neurotoxic, meaning that it directly harms the brain. One of the primary mechanisms of alcoholism is that the damage caused by alcohol directly contributes to future alcohol cravings. A lot of people have problems with anxiety - they would be wise to discontinue caffeine intake altogether as it is a major risk factor in anxiety disorders.

Meditation has a host of benefits and structural changes have been observed in the brains of practitioners - http://www.scientificamerican.com/podcast/episode.cfm?id=med...

Exercise is absolutely essential and, frankly, should be a first-line treatment for things such as depression.

There are also a few new and interesting nootropic substances such as Piracetam, Aniracetam and Noopept, the last one being the most effective for me personally.

All the wise folk say that the body should be treated like a temple. I completely agree with them since the mind and the body are but one and the same. Treat the body right and the mind will follow. Treat the mind right and you will feel right.