Adrian Warnock is stirring up a conversation on Christian Counseling where he invited thoughts from readers.
First, I would not want to ignore or deny the role of actual physical and medical roots of certain psychological problems. For those familiar with the U.T. sniper many years ago, he had a physical abnormality in his brain. There is no doubt that some psychological problems are medical, having a physical or chemical basis. While counseling is not going to resolve a biological problem, it can help with other types of problems.
In this conversation I'm assuming the context of Christian counseling: a Christian counselor and a Christian seeking help. At the risk of repeating what other people have surely noticed, here are some thoughts on how Christianity can build mental health. I'll keep them brief:
Problems with acceptance of reality
Perfection in this world is an unrealistic goal. Jesus tells us, "In this world you will have trouble." On a Christian view, imperfection does not interfere with something being truly valuable in God's sight. There is a framework of hope that expects God will keep his promise to redeem us and this fallen creation. In light of this, we can more readily admit that things are not as they should be or as we wish.
Problems with self-control
Everybody who tries to lead a holy life struggles with self-control at some point. This includes both addictive behaviors and other "loss of control" scenarios such as rage or abusive behavior. Christ insists on both forgiveness of sins (God remembers that we are only dust, fragile and frail) and on putting our whole-hearted efforts into turning our backs on sin. The Christian is encouraged to make repentance a daily struggle. Consciously turning away from destructive things and turning towards God are a way of life. As a practical matter, Christianity recognizes that the struggle against a problem may well be life-long. The constancy of Christ's love, the depth of his forgiveness, and the firmness with which he insists that we turn our backs on sin are all necessary for a struggling person to maintain perseverance and hope.
Problems with guilt
Christ's forgiveness is the antidote to the poison of guilt. A person's reluctance to accept their own forgiveness finds its answer in the cross of Christ. There is nothing we have done which would have demanded a more horrible or severe penalty than Christ has suffered. Christ's sacrifice for the sins of the world is the healing of our wounds. This also makes honesty about our faults less frightening.
Problems with self-acceptance
Christ befriended the despised of society. He didn't consider it a problem even when they were despised for good reason. Every once in awhile a person may think, "If people knew such a thing about me, they would despise me." That may even be true. But Christ came to seek the sick, those who need a doctor, and to heal them.
Problems with acceptance of others
Have you ever had an irritating, obnoxious, or annoying person amongst your coworkers or family? The acceptance of others begins with knowing that Christ values the person and died for them; he came for the lost, the sick, and the unrighteous. Acceptance of others is also helped by the honest knowledge that we have real faults ourselves. In accepting and loving someone who has real faults, we simply do for other as we would have them do for us. For those tempted to deny the reality of faults in people they love in order to maintain love, this provides a healthier framework for seeing the reality of the fault but keeping it in perspective.
Problems with resentment
Resentment, stewing on wrongs of the past, is a problem with forgiveness; likewise bitterness. These are mind-corroding emotions. Forgiveness does not mean that the wrong was really ok. Finding an excuse is not granting forgiveness, but denying the need for forgiveness. Christianity allows us to take an honest look at the actual wrong done, making no excuses, yet still helping with forgiveness through the cross of Christ.
Problems with grief
Grief over the deaths of loved ones can cause a long-term struggle. The resurrection of Christ and Christ's promise that he will raise us up at the last day are the only genuine consolation in the face of death. The fact that things may never be the same again can be faced squarely and accepted as part of the cross that we bear. The fact that memories are an inadequate substitute for a real person is also faced honestly.
Problems facing mortality
As grief over others' deaths can plague us, so can fear of our own death. Christ's resurrection means that the rational response to thoughts of our own death is to trust Christ, who promised he would raise us up at the last day.
Problems with stress
The background of a Christian's approach to stress is trust in Christ's statement: "In this world you will have trouble, but take heart; I have overcome the world." Even the worst defeat and damage are, in the end, reparable. God does not promise an easy life, but he does promise both his love and his redemption.
Problems with meaninglessness
It is a common experience for Christians to read Jesus' teaching on the sheep and the goats and know inside themselves what it is they hope to do for God in this life. Christianity encourages us to devote ourselves to practical action to help where help is needed most, acting in simple ways that are within our reach, as Christ has taught us. Christianity also teaches us not to despise the humble and simple things; the first people we care for are within our own families.
No doubt there is more room for discussion under every point. But in short, Christ's life, death, and resurrection provide an objective basis for hope, honesty, perseverance, compassion, and love. The Christian counselor has a far more profound way of helping someone than merely advising them to try again. They can offer them legitimate reason for hope and for perseverance, even in the face of a life-long struggle.