Trying to cope with something that happened thirty years ago (and bring my family closer together again)?

In 1981, my eight-year-old brother Andrew was kidnapped by a family acquaintance and held hostage for three weeks. During this time, he was routinely beaten and sexually abused by his captor. He was also burned with boiling water and forced to listen while his captor made crank calls to our family pretending to be the police, telling us that Andrew had been found. He was rescued after three weeks. It had taken that long to track him down because his captor had them moving around all the time. It's strange to me how a period of time as short as three weeks could destroy so many lives, and leave so many still broken after thirty years. Andrew's body recovered from the trauma, but his mind never healed. The Andrew that came back to us was not the Andrew we had previously known. Before the trauma, Andrew was very social and outgoing. We were only two years apart and always very close. I never had any other brothers or sisters. He was a sweet little boy with a good sense of humor, and, being an older sister, I teased him constantly. Not meanly, but in a playful way. He is the most ticklish person to ever walk planet Earth, and as a little kid he loved it when I tickled his feet. We wrestled and play-fought and just enjoyed being with each other. When he came back, everything changed. Andrew had always been close to me and my parents also, but after he came back he acted like he couldn't even stand the sight of us. I could never understand that. I thought he should be happy to be back with us, people who loved him. He told me when he was older that I was a stranger to him and that there was a gulf separating him from everyone else. He was resentful that other people hadn't been where he had been. When he first came back and started beng like that, I tried so hard to bring him back. I tickle-attacked him like I used to and even though he squirmed and laughed just the same, he didn't enjoy it at all. He wouldn't wrestle either, and didn't seem to want to be around me at all. He did well in school and never had issues with drugs and alcohol, he's been successful in life and has a wife and kids, but for the past thirty years you can tell that something in him is just gone. Something inside him died all those years ago and, despite this, I still hope so hard that I can bring him back. I still see him and our children play together, but that confidence is gone. He underwent counseling as a child and teen but it didn't help him and he doesn't see anyone anymore. I encourage him to see someone about his depression and the pain he still feels but he says it wouldn't make any difference. I'm sorry this post is so long but I just don't know what to do to help him. He's physically healthy and financially stable, but I want to be close to him again and my parents want the same. Is there anything I can do to bring him back, to make us all just a little closer?