Many people I work with grew up in households where one or both parents were struggling. It is almost never the case that the parents were bad or intended any harm to their children, it is more often the case that they struggled due to depression, poverty, their own histories of trauma, or something else that they themselves did not create or wish to have happen. Often they were working very hard to try to cope with their difficulties and trying to minimize the impact on their children, and tried very hard to be good parents. However, they usually could not protect their children from experiencing at least some of the impact of their struggles.
I have noticed that many people who grow up in these kinds of households experience similar challenges as adults. So much so that when I first begin working with a person and hear them talkng about issues such as guilt, feeling burdened by other people, and feeling fearful of burdening others themselves, I can ususally make a fairly accurate guess about the kind of home environment they experienced when they were growing up. Much of our work becomes about tracking connections between their struggle and their upbringing, gradually reducing the sense of guilt and responsibility toward others, and starting to express their own needs to be able to have more equal and satisfying relationships. Here are some of the common patterns I notice.
Firstly, many children in struggling households become helpers as adults. Children need to feel like their home environment is stable and predictable enough to be able to focus on the tasks of their development (education, making friends and learning how to be social, developing a sense competence in doing things for themsleves, building self-esteem etc.). If the home environment is not sufficiently stable, it makes it hard for children to focus on what they need to be doing. It's like if you were working in a building that was crumbling. It would be very hard to focus because you would be worried about the building around you falling apart. When the building is stable, you are able to ignore it and focus on your work.
When the home environment is not entirely stable, children will often compensate by taking on the role of the helper. The belief they (usually unconsciously) carry is that if they can prop up their parents then that will stabilize the environment, and they can then focus on their own tasks. What they don't know is that stabilizing the environment is usually beyond their capability. Children cannot heal their parents' depression, or resolve their trauma, or fix addiction, or reduce poverty or most of the others things that cause destabilization. The result is that they work harder and harder to prop everything up and increasingly take on the role of the helper. But rarely does anything get fixed, so they can end up feeling overwhelmed and unsuccessful, and sometimes carry this theme throughout their lives: worrying about the dependability of other people; working hard to take on the burdens and concerns of others; feeling that others may not be able to cope without the help; and trying to be the stable helper. They often feeling overwhelmed by the tasks they take on, unsuccessful at carrying them, and then either depressed themselves at their perceived failure, or angry at other people for allowing them to take on the burdens and not reaching out reciprocally to help.
A second thing that happens in this environment is that children often learn not to communicate their own needs. Often they feel that if they put their needs on their already struggling parents then it may crush them entirely, so they learn to repress their needs and focus on taking care of the needs of their parents. Because they also often experience carrying the needs of their parents as overwhelming, they can struggle later in life to reach out to others for support or communicate their needs to others. On some level they fear it will destabilize their relationships and the wellbeing of other people (as they feared it would for their parents) and that it will burden others to hear their needs in the same way that they felt burdened by carrying the needs of their parents. Much energy is usually going out to help others, but often little comes back, partly because they find it hard to ask for support, and appear to others on the outside as happy to take the burdens on.
A third pattern is that they often feel responsible for problems, so experience high levels of guilt. This happens because most children, when there are problems in the home and their parents are not functioning well, tend to blame themselves for the problems rather than their parents. This happens for a couple of reasons. Firstly it is more hopeful to blame yourself. This might seem strange, but if you really knew that you, as a child, were unable to fix your parents then that would be devastating because you would lose hope that the situation could get better. If you blame yourself then at least you have the hope of being able to fix the problem and feel like you have some control over doing so. Secondly it usually doesn't occur to children that their parents could be the source of problems. Parents usually seem larger than life and somewhat infallible to children, so it usually seems more likely to children that they themselevs are doing something wrong when there is a problem happening in the home.
As a result, children in this situation go through childhood carrying a lot of guilt about the problems in the household, even though it is not their fault, and go into adult life feeling the same way when problems happen in relationships. The automatic thought is usually "I've done something wrong" and it becomes hard to accurately judge who is responsible for what when a problem happens.
To recap, common patterns for adults who have grown up with parents who were not functioning well are that they often take on the role of the helper with other people in their lives, but frequently have a hard time asking for help themselves and can feel overwhelmed and unsuccessful in the helper role (though they often end up in helping professions such as nursing or social work and can do some amazing work and gain great satisfaction in these careers because they are so adept at helping); they can have difficulty communicating their own needs and often worry that depending on other people will burden them in the same way that they felt burdened as a child; and they often carry around a lot of guilt in relationships and have a hard time distinguishing responsibility in issues that arise in relationships.
Psychotherapy can be an excellent place to untangle this web. I find that in a reatively short space of time most people are able to begin understanding the connections between their upbringing and their current struggles, are able to reduce their sense of responsibility and failure, reduce their sense of guilt, reduce their fear of burdening other poeple, and begin reaching out for help to others, which results in less stress and more satisfying and close relationships.