The most critical parental task is to enable their child's eventual independent functioning with the greatest tragedy being when things go severely awry. When their adult child, though having completed formal education, still lives at home, unemployed and dependent on their parents. Here, I'm not referring to the national economy but to an adult who, for psychological reasons, cannot function as society expects. They wasting their days playing video games or dozing, resistant to suggestions on how to improve their life. Even worse is when substance abuse is involved.
There are no easy quick solutions for what to do. A positive element is when the child is receptive to psychotherapy, during which the parents should also be advised on productive family interaction and provided emotional support. For those with more severe emotional difficulties, participation in a day hospital program can be helpful.
During this, the patient engages in a daily routine of individual and/or group psychotherapy and social interactions including lunch. This involvement can be life-changing with other problems too. An elderly woman, following the death of her husband after their long marriage, "came together" and became a valued helpful figure to the other far younger patients. But sadly, because her problems didn't fit the criteria for day hospital participation, she had to be discharged.
The most helpful parental attitude is to relinquish feelings of guilt and search for a solution. One mother, who I stated was worthy of a Presidential Medal For Parenting (if one existed), had the most helpful attitude when a problem erupted with her teenager. Rather than bemoan her fate, the mother would determine how the problem could be fixed, and then do it!