Neurofeedback training is a learning process and results occur over time. Improvements in many conditions can be seen in ten sessions, though permanent changes take longer. It may not always be possible to predict how successful training may be for every individual, but a reasonable expectation of results can usually be seen early in the course of training. Initially sessions need to be regular and frequent with a minimum of two sessions a week. As the brain re-regulates to healthy patterns of brainwave activity, the frequency of the sessions can then be decreased. Many symptoms are "permanently" reduced by 30-40 sessions. However, developmental disorders such as Autism may require many more than the standard protocol due to the complexity of issues being dealt with. The amount of time depends on the type of problem, consistency of training, presence of medication in one's system and especially how well other areas of one's life are managed in terms of nutrition, activity level (ex: frequent computer and TV usage; lack of exercise) and sleep routines.
The formation of new neurons and connectors in the brain typically requires at least two months to begin to develop. Neurofeedback changes existing patterns while encouraging the development of new neuronal connections. This is why changes can be seen after a few sessions but may take longer to become permanent.