One major theory address the social aspects of human suffering, and thus may be helpful to know about when pursuing a self-help agenda. Family Systems theory can help provide you the perspective to see that your problems may be larger than you think they are, caused by forces not directly under your control, and affecting people beyond yourself.
Family Systems theory was created during the middle of the 20th century when the idea of ecology was borrowed from biology and applied to the study of human problems. Ecological thinking teaches that individual creatures cannot be adequately understood when studied in isolation, but rather must be appreciated within their network of relationships to the other creatures around them if their lives are to make sense. Individual creatures depend upon their network of relationships with other creatures (animal and vegetable) for their survival; This is apparent in the relationship between flowers and bees, where bees use the flowers as a source of food, and the flowers depend on the inter-flower traffic that the bees provide to spread their pollen and insure healthy genetic diversity within the flower community. These two species are interconnected and cannot be understood in isolation. If the bees become damaged, the flowers suffer, and vice versa. When any part of such a network is altered or damaged, it affects all the other parts of that network, for all are interconnected.
The Family Systems insight is that what is true about flowers and bees is also true of human relationships. People live in families and social groupings, and depend upon one another for the means that insure their mutual survival, including (as Maslow has taught us) food clothing and shelter, but also safety, belonging and social support. Family members are interconnected: Every person within a family has a role to play within the life of the family as a whole. Alteration or damage to one family member affects the entire family, for all are interconnected.
Family Systems theory's ecological view of the family makes it very different than conventional psychological theories. Where other psychological theories view problems as things that occur within individuals, Family Systems theory takes an ecological approach, viewing problems as things that occur between people. They tend to see individual problems as instances of larger relationship problems occurring within families (or within communities or society). This means that when a family member becomes depressed, the effect of that depression are not localized within the depressed person, but rather affect all family members. It is thus a family problem, not an individual one. The depression may even be a consequence of some other family problem. For example, a mother's "empty nest" depression (occurring when her last child leaves home) may result as much from the radical alteration of her day to day family life as from any chemical problem she may have.
Family Systems theorists pay careful attention to the boundaries between family members, because such boundaries are exactly where problems tend to manifest. A boundary is a sort of psychological perimeter and definition that people draw around themselves, and around particular relationships they are involved in. Boundaries mark off where one person or group ends and another begins. Healthy boundaries act as containers that keep things apart that need to stay apart, and also as roles that help people to know how to act. The boundary around the family as a whole helps family members know who is a member and who is not, for instance. The boundary around the parents helps them keep their adult sexuality and communication apart from their children. The boundary around each child and adult within the family helps each family member keep some secrets that are theirs alone.
Family problems occur when boundaries become strained or break and members are put into situations that may harm them. Incest situations are probably the worst sorts of boundary violations, but others are also worth pointing out as examples. Families dealing with spousal abuse often fail to protect their children from that abuse (as well as vulnerable spouses from abuse), resulting in traumatized children and adults. Alcoholic parents may be incapable of taking care of themselves, influencing their children to become "parentified" (e.g., responsible before their time). Angry divorced parents may start fighting through their children (a situation known as "Triangulation because of the shape of the communication communication)", in essence making them into unwilling messengers, filling them with venom and forcing them to choose between parents. Family systems therapists look for patterns of boundary violation in the families they work with, and then work with family members to try to correct what is bent or broken.
For all that family members are bonded, they are frequently blind to how much they are ecologically interdependent with one another. It is very disturbing to most people to think that they might be contributing to a problem. For this reason, dysfunctional families are often quick to blame individuals within the family for their woes, falsely localizing the cause of their pain into a scapegoated member. The family that has created an "identified patient" through this process may still be quite dysfunctional, but this fact becomes conveniently less apparent to the members. A family systems oriented therapist who might work with such a family would look to see whether any identified patients had been created, and then work to educate them as to the truer ecological nature of their family issues.
The key insights to take home from family systems theory are that: 1) the problems people have frequently reflect problems experienced by the families and groups those people are a part of, 2) it is necessary to address family or group problems at the family or group level (the "system" level) if they are to be resolved, and 3) the way to identify what is going wrong within a family or group is to pay attention to how the boundaries governing the family or group members are functioning. Frequently, role transgressions (e.g., abuse situations, failures to carry out particular responsibilities, etc.) serve as good indicators that boundaries are not functioning properly.