I made a post about this last year, but I think it bears repeating.
There are several ways to help your body produce more serotonin. Some people have levels that are naturally depressed and some have levels that have been artificially depressed due to chemical indulgences. Regardless, these tips will work for both situations.
Sunshine.
Natural sunshine helps the body produce more serotonin. Get OUTSIDE! (or sit in a sunny window) :)
Tryptophan.
Tryptophan gets converted to serotonin. You may think immediately of turkey, but you are only partly right. Turkey has LOTS of tryptophan; however, the absorption of tryptophan is hindered by protein. Thus, if you have a turkey sandwich, you're not going to get the turkey-tryptophan high that you think you might. What aids the absorption of tryptophan is carbohydrates. Carbs help speed the tryptophan to the brain where it gets converted much more readily to serotonin. THIS is why you will get a tryptophan high at Thanksgiving. It's not just the turkey; it's the turkey + the mashed potatoes + that rice dish from your aunt + the fruit salad + whatever other carbolicious dish you feed yourself. Your brain is flooded with serotonin and your blood sugar is sky high and now you have a happy food coma. And then your whole family's blood sugar collectively crashes and everyone starts fighting. This is why excess carbs are not always fun. Just enough is vitally necessary.
Bananas.
Bananas make me deliriously happy. Bananas have tryptophan. They don't have nearly as much tryptophan as turkey or chicken, but what they have that turkey and chicken don't is a good amount of carbohydrates and pretty much zero protein. This is good because eating bananas (especially the super ripe, sweet ones!) speeds the tryptophan to your brain and voilà, serotonin! Yay! Super Banana Happiness! Wheee!! The carbs in bananas help make the smaller amount of tryptophan contained within bananas much more effective.
5-HTP.
This is a supplement which you can purchase at healthfood stores. Some people use it in lieu of anti-depressants, though the side effects (usually, but not limited to, nausea) can be kinda harsh. I've never taken it, myself, but I know plenty of people who have. 5-HTP is the intermediary step in the conversion of tryptophan to serotonin: tryptophan --> 5-HTP --> decarboxylase --> serotonin
There are certain vitamins that help in this conversion
*: B6, niacin, and magnesium.
B Vitamins.
Niacin is important for two reasons. If you're taking 5-HTP, niacin helps convert it to serotonin. Also, IIRC, if the body is depleted of niacin, the body will use tryptophan to help produce more. This means less serotonin for you to enjoy because the tryptophan your body does have is being diverted from serotonin production to niacin production. So if your body has enough niacin, then your body doesn't need to grab from your tryptophan store to make more. This means more serotonin for you, which is happiness.
Also, niacin has a calming effect on one's nerves. It, out of all the different B vitamins, is among the most helpful when dealing with stress. When your serotonin levels are depressed, so are your coping skills. Upping your intake of niacin will help you stay calm and avoid some of the hideousness that accompanies lowered serotonin levels.
Pyridoxine, or B6, helps in a couple of different ways. When paired with magnesium OR with 5-HTP, pyridoxine amplifies serotonin production. This is especially important for women on BC pills to note because BC pills are notorious for depleting one's B6 levels. Because B6 is a "cofactor for enzymes that convert L-tryptophan to serotonin and L-tyrosine to norepinephrin.... [a] vitamin B6 deficiency might result in depression"
* B5 (Pantothenic acid) helps you to stay calm, as well. It makes "cortisone and other adrenal hormones that counteract stress.
*"
Vitamin C.
This baby doesn't just help boost immunity, it also helps convert tryptophan to serotonin. Vitamin C is your friend!
Magnesium.
Magnesium is especially helpful if your lowered serotonin levels are due to chemical indulgences OR if you are on SSRIs. Magnesium helps allay cramping. There is some sort of connection, I have found, between bruxism (clenching your jaw) and serotonin levels. I have experienced this both on celexa and on E (independently of each other -- don't do E if you're on SSRIs OR on MAOIs -- that's asking for more trouble than you really need. be good to your body, or at least be not as bad to your body as you could be.) Magnesium helps with the jaw clenching.
(Magnesium also helps with RLS: restless leg syndrome. If you don't know what this is, then you probably don't have it. There is apparently a link between RLS, ADD, and sleep disorders. Research [by people way more qualified than me] is currently being done, so you shouldn't have to go too far afield to find correlative studies.)
Omega-3 fatty acids.
Omega-3s "may influence serotonin functionality in the brain"
* Meaning, basically, that Omega-3s help serotonin do what it needs to do. It helps it get where it needs to go. Most people in North America do NOT get enough Omega-3 fatty acids. This is a bad bad thing. Eat more fresh salmon, fresh tuna and mackerel. Use canola oil in cooking. Eat lots of walnuts. Add freshly ground flax seed to any dish that seems like it would go with (try it with everything! even ice cream!). Take Omega-3 fish oil supplements. Aim for 1000-2000 mg/daily. Much more than that, and you could have problems with blood clotting, as excessive Omega-3s thin the blood.
This PSA has been brought to you by a banana-crazed magic fox. Thank you, and be good to yourself.