Thanks for asking. If they have gotten proper help, the diagnosis has been reactive attachment disorder. However, all of these children are complex. In fact, we refer to it generally as "Complex Trauma." Most of these kids have many other diagnoses including oppositional defiant disorder, anxiety, PTSD, fetal alcohol, bipolar disorder, significant learning delays of all types*, adhd, etc. These kids have often been hit genetically and environmentally with lots of deficits.
Interesting on the learning deficits, my child has a nonverbal learning disability and also tends to take things VERY literally. When I have watched JA argue about specific words in a very literal sense, I have recognized that. While there is no doubt she is vying for control and being difficult, I also sense that she may have difficulty processing the questions as most people would. Her word "hyper-literal" would be very accurate for my child, as well.
Although I work with biological families too, our families are mostly adoptive families where there is clear evidence of abuse, neglect, or chronic instability in the first three years of life which alters brain function. Add drug exposure or fetal alcohol and that compounds things. Then, with altered brain function, you see some common traits such as failure to emotionally regulate, no impulse control, etc. These traits then often lead to the ADHD diagnosis and others. So, again, the commonality to my families is the early trauma. Some of our kids have a long list of diagnoses because of these brain changes and alcohol exposure.