That's not what I said.
What you today call mental problems just didn't have that name in the bible. The same problems we label today as mental issues, back then were dealt with by casting the demons out. Instant results.
Here's a few to illustrate it.-
Here's one of your "mental" problems, healed by casting the demons out
Lk8v29For He was commanding the unclean spirit to come out from the man. For it had seized him many times, and he was bound, being kept with chains and shackles. And breaking the chains, he was driven by the demon into the deserts.
Here's another "mental" problem, again healed by casting the demons out
Mark9v17Then one of the crowd answered and said, “Teacher, I brought You my son, who has a mute spirit. 18And wherever it seizes him, it throws him down; he foams at the mouth, gnashes his teeth, and becomes rigid. So I spoke to Your disciples, that they should cast it out, but they could not.”
19He answered him and said, “O faithless generation, how long shall I be with you? How long shall I bear with you? Bring him to Me.” 20Then they brought him to Him. And when he saw Him, immediately the spirit convulsed him, and he fell on the ground and wallowed, foaming at the mouth.
21So He asked his father, “How long has this been happening to him?” And he said, “From childhood. 22And often he has thrown him both into the fire and into the water to destroy him. But if You can do anything, have compassion on us and help us.”
23Jesus said to him, “If you can believe, all things are possible to him who believes.” 24Immediately the father of the child cried out and said with tears, “Lord, I believe; help my unbelief!”
25When Jesus saw that the people came running together, He rebuked the unclean spirit, saying to it, “Deaf and dumb spirit, I command you, come out of him and enter him no more!” 26Then the spirit cried out, convulsed him greatly, and came out of him. And he became as one dead, so that many said, “He is dead.” 27But Jesus took him by the hand and lifted him up, and he arose.
Here's another "mental" problem, hearing voices! Paul sorts it by casting the demon out!
Acts16 v16Now it happened, as we went to prayer, that a certain slave girl possessed with a spirit of divination met us, who brought her masters much profit by fortune-telling. 17This girl followed Paul and us, and cried out, saying, “These men are the servants of the Most High God, who proclaim to us the way of salvation.” 18And this she did for many days.
But Paul, greatly annoyed, turned and said to the spirit, “I command you in the name of Jesus Christ to come out of her.” And he came out that very hour. 19But when her masters saw that their hope of profit was gone, they seized Paul and Silas and dragged them into the marketplace to the authorities.