My husband and I raised three long-term foster sons in addition to our birth daughter. Because of confidentiality I can't go into details, but the boys had a lot of special needs. All three were deaf, two had vision problems, two had learning disabilities, two were diagnosed with ADHD, one had a seizure disorder, one was autistic, one had a personality disorder, and all three had emotional damage. Obviously they wouldn't have been in foster care without problems in their birth families, and being passed around from home to home would harm any child emotionally. One of them had also been abused.
People often ask us why we got and kept the boys since they had so many problems. When we married both my husband and I knew children whose parents didn't want them because they were deaf, so we decided to adopt deaf kids. For various reasons we weren't actually able to adopt any of the boys, but when we got them we assumed they would stay with us permanently and considered them our own kids.
As I mentioned in my previous post, at that time deaf children had usually been prevented from learning Sign Language. Many children in the school where I worked had frequent tantrums, which stopped once they learned to sign and could communicate their needs and frustrations. We assumed the two foster sons' tantrums were caused by the same thing, and by the time we figured out they had other problems we had already emotionally bonded with them.
All three boys left us for various reasons when they were in their teens. They are adults now and haven't lived with us for years, but we still consider them our sons and have stayed closely involved with two of them.