1. serotonin depletion. (get some L-tryptohan, natural essential amino acid...meaning you must get it from your diet) try taking 50-100mg a night after you eat. DO NOT DO ANY STIMS DURING/IMMEDIATELY AFTER TAKING L-TRYPTOPHAN...A GREAT WAY TO ENTER PSYCHOSIS!!...
2. Mal-nutrition. taking a multi vitamin everyday wont save you. You need proteins, sugars etc for your body to re-produce dopamine, serotonin. etc.
3.tolerance to the drug can cause a paradoxical effect. its believed (arguably) that after long term use your brain anticipates the reaction and puts up some kind of chemical barrier because your receptor sights and so fried ur brain is desperate.
4. Bad Meth! This is more common then people think. One day their meth makes them alert and awake, next time its a different batch and they enter the matrix....sometimes the cooking method may vary due to a lack of a certain compound and so a substitute is used. I have read about this before. But i dont want to encourage you to seek out a new source of meth.
5. you have add or adhd and havnt been diagnosed.
6. Sleep deprivation is a serious problem. when your asleep your brain is most active, fixing itself, stocking the shelves, storing memories, repairing itself etc. you can become psychotic from lack of sleep, not so much the drugs.
But ultimately you really need to give it a break. If you cant control yourself there are doctors out there that can give you something to help your brain recover and ease withdrawls. Its not just ...you take a drug and boom dopamine makes you happy. its a very complex process that involves other neurotransmitters, meth causes massive release of serotonin. As a result something happens to your norepinephrine density in certain receptor sites, this causes this....that causes this....and so on. Did you know that a overload of dopamine can mess with ur immune system?
anywho....A sure thing is to just give it a rest. Your brain knows what you did to it, and it will remind you!
