Natural herbs may be of interest also, especially St. John's wort, it has few side effects and appears to alter serotonin function.
Prozac - fluoxetine (and paxil) was invented at Eli Lilly. It works by inhibiting the reabsorption of serotonin into neurons. This increases the amount of serotonin in the brain, and thus lessens the feeling of anxiety and depression by making people more optimistic. Some doctors may use botulinum toxin - Botox or even blood pressure medications. Treatment with Tofranil is intended to desensitize by breaking down nor-epinephrine and serotonin. Then there is Lithium - a mood-stabilizing drug available in nature (salt).
Note: Some drugs have terrible side effects - blurred vision, constipation, drowsiness, sexual dysfunction, weight gain, nausea, insomnia and even death when mixed with cold medications or Tyramine foods. Be aware that these drugs require a doctor's approval.
There is also the choice of using electroconvulsive therapy when drugs are ineffective. This form of therapy is geared at changing brain chemistry by affecting neurotransmitters through use of quick electric shocks in the brain that produces seizures.
Great foods for relieving anxiety and stress. It is possible to take tryptophan supplements with fruits before bed, because it needs insulin to do its work before serotonin, which makes melatonin. You can also do this before driving since serotonin makes you feel good about what you are doing. Also, check out vitamin B-6, it helps to promote neurotransmitter effectiveness. Next, definitely snack on blueberries, dark chocolate, fatty fish and omega-3-rich foods including sunflower seeds - a staple snack at baseball games.
Finally, avoid driving during the early evenings into darkness, because as melatonin increases serotonin levels decreases, otherwise you will need more tryptophan uptake to make more serotonin. You can do this by eating more carbohydrates such as snacks which creates insulin in the pancreas. So, by changing your eating habits and behavior, you can affect your anxiety by changing your serotonin levels.