<qa>  What is the most common cause of asthma?Effective therapy of asthma still remains quite serious problem. According current opinion of leading specialists, asthma is an inflammatory disorder. But asthma also is a paroxysmal disorder: many specialists underline paroxysmal clinical picture of asthma. According to some authors, neurogenic inflammation may play important role in asthma mechanism. But migraine and trigeminal neuralgia are also neurogenic inflammatory paroxysmal diseases, and some antiepileptic drugs, like carbamazepine and valproates, are very effective in therapy of these diseases - more than in 80 of cases. If bronchial asthma also is paroxysmal inflammatory disease, we can suppose a possibility that some antiepileptic drugs also may show high efficacy in asthma therapy. Taken in consideration this hypothesis, we performed a double-blind, placebo-controlled 3-month trial for evaluation of carbamazepine efficacy in treatment of patients with mild-to-severe bronchial asthma. 