Note that the subject of suicide has already been discussed (What does the Bible say about suicide?), though not this question.
The Scriptures clearly state that any sin can be forgiven if the sinner believes that God can forgive. I believe Judas could have been forgiven if he had turned to God instead of suicide. His however is a unique case, because we know what his final thoughts were regarding his guilt at having betrayed the Son of God and his story is recorded in inspired scripture. We are not in a position to fully understand the mindset of a successful suicidee.
Researchers characterise suicide as an exclusively human response to extreme psychological pain. For the sufferer it is a lonely and desperate solution. They can no longer rationally see any alternative. As followers of Christ, we do know that he and our Heavenly Father are aware of our innermost thoughts and are full of mercy and compassion. If a brother or sister of Christ commits suicide we have no right to condemn or pass judgement one way or the other. At his first coming, Jesus healed more than one demon-possessed and gave them a “right mind”. Since we believe he will heal the blind, lame, and deaf at his second coming, can we not also believe that those saints whose minds have become tormented and possessed by the “demons” of this age will also be made whole?