Broadly speaking, one should always bring concerns before God in prayer. Confession is not for the healing of the physical body (including the brain), because individual illnesses are not generally seen as the result of individual sins. That said, the rite of Holy Unction (healing) does include many prayers for the healing of the soul, since any corruption of the body is the result of our categorical separation from God's Eternal Life. The rite of Unction ought to be practiced in the community of the Church, since our separation from one another is an additional resulting tragedy of illness. Healing our isolation from God and from one another are major components of the rite; if God chooses to perform a miraculous healing for His Glory, then we celebrate that. There are many such stories in our hagiography and most parishes have plenty of miracle stories sitting just beneath the surface if you ask with enough sincerity. Americans sometimes get the willies at miracle stories, though, so sometimes it takes a bit of poking. But they are there, because God is active in His Church.
That said, if one is sick, one should seek healing from physicians specializing in the illness. If the sickness is of the body, then one should seek help from doctors of the body; if it is of the mind, then one should seek help from psychiatrists or psychologists; if it is of the soul, then one should seek help from an experienced doctor of the soul.
So generally, Orthodox Christians seek and use medical expertise. Many Orthodox Christians are doctors and nurses (great service professions!), psychologists, psychiatrists, and teachers (doctors of the mind and intellect). Most succinctly, we welcome God's intervention on the terms God chooses to provide it; if that intervention comes through the loving hand of our sister or brother (a doctor), then glory to God - if it comes through direct Divine action as the result of prayer, then glory to God.
Ultimately, though, all such healing is temporary. We all die. We all must die, so that we may be made alive in Christ and Christ alone. Without that death, we humans rather stubbornly hang on to the illusion of our self-determination and self-control, and in the presence of such illusions God's activity is stymied by our pride.
In Christ,
Macarius