A lack of dopamine (especially in the extrapyramidal system) is what causes Parkinson's. An excess of dopamine (especially in the mesolimbic pathway) is what ca

A lack of dopamine (especially in the extrapyramidal system) is what causes Parkinson's. An excess of dopamine (especially in the mesolimbic pathway) is what causes schizophrenia. Nicotine does increase dopamine in the brain, but only in the same way that my car plays music. It does that, but it's not really relevant to the way nicotine works -- nicotine acts to stimulate an ion channel called the nicotinic acetylcholine receptor. This ion channel stimulation causes several downstream effects, most notably the release of endorphins (biomolecules which mimic the function of morphine), and also the release of adrenaline (which increases focus and concentration).