Kindling models and antikindling effects of mood normalizers

In animal experiments, kindling designates the appearances of increasing EEG and behavioral responses when an initially ineffective stimulus on certain cerebral areas is repeated (Goddard et al., 1969). Its development occurs in association with increasing duration and spread over the major part of the brain of electric afterdischarges. This process may lead to critical changes in behavior. Kindling can be caused by electric stimulation or pharmacological inducement. The nature of the behavioral response varies with that of the stimuli, so different types of kindling have been described, constituting animal models notably for epileptogenesis. Their psychiatric interest stems from evidence of an inhibiting effect of certain substances, such as carbamazepine or phenytoin, which are effective in the treatment of both epilepsy and mental disorders, but this effect is also found for lithium (Post et al., 1982, 1984). Applied to the development of periodic psychoses, kindling models would account for certain unexplained clinical data and precisely explain the mechanisms and the specific action of various mood normalizers.