Q&A: Theory: Psychological development has two dimensions

A school of thought, first introduced in the 1970s, holds that depression and perhaps most mental illness, stems from disruptions in psychological development. Introduced by Sidney J. Blatt, Ph.D., professor of psychiatry and psychology at Yale University, the theory contends that psychological development has two basic dimensions: a sense of self and a relationship with others. Any disruptions or an exaggerated emphasis on either dimension will lead to mental disorders.

According to Blatt, this theory is a break from current treatment modalities that would see illness as a cluster of symptoms. In two books on the subject, “Experiences of Depression: Theoretical, Clinical and Research Perspectives” and “Polarities of Experiences: Relatedness and Self-definition in Personality Development, Psychopathology and the Therapeutic Process,” Blatt highlights numerous research supporting the idea that “psychological development is a careful balancing act between the two polarities.”

Blatt spoke with New England Psychologist’s Catherine Robertson Souter about his theory and how it has been and is currently received within the psychology field.

 Q: You’ve been working on this theory and supporting research for nearly 40 years. Can you provide a brief overview?

A: We each evolve from infancy through senescence struggling with two major tasks – to develop quality of interpersonal relatedness and to have a sense of who we are. These two developmental lines evolve in an interacting synergistic dialectic throughout life. When we have sense of relatedness it gives us a sense of who we are and as we revise a sense of who we are, we evolve a more mature level of relatedness and so on.

 I’m interested in how we become a person – how that development of becoming a person evolves psychologically over time with the people who care for us and we are engaged with and how that process gets disrupted and how that leads to psychopathology. Having that view of psychopathology enables me to understand the issues behind the symptoms.

 Q: You first noticed this dichotomy while doing research on depression?

A: There is a whole theoretical literature throughout psychology in the second half of the 20th century that specifies that these are two of the most fundamental dimensions of psychological being.

 Back in the early 1970s, I became aware of two forms of depression. There is the classic depression that everybody writes about around guilt and self-definition. But there’s another type of depression around loneliness and feeling unloved and abandoned.

 The book I published in 2004, “Experiences of Depression,” is a culmination of research that stemmed from that initial observation in 1974 (and that, with colleagues, I published some empirical support for in 1976). Since that time, a number of other investigators in depression have made this distinction.

 Q: How have you seen this theory received over the years?

A: There’s been an enormous amount of research on this mainly from a psychological point of view. It has not impacted as fully in the psychiatric community, but a lot of research in depression by psychologists is around these two dimensions.

 It takes time for things to filter through the system. Of course, I would have preferred it to have been more rapid and had more impact but people are trained and committed to a certain point of view. That’s part of the problem with the field is that people don’t read the literature and explore other points of view. That’s true of me, too.

 One of the major current issues in mental health is the revision of the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Illness – the DSM. Some of the task force working on the revision of the DSM-V, have noted the importance of the two dimensions of relatedness and self-definition and have integrated it into some of their work. But, in my judgment, they have not utilized this conceptual structure to its full potential. I hope a recent chapter (2009) presenting my approach, in a book edited by Ted Millon and Robert Krueger on future directions of the DSM, may call the attention of the DSM task forces more fully to the two polarities model.

 Q: Tell us about some of the research that has been done?

A: There are at least four instruments that measure these two dimensions, which we think are central to depression. Using these instruments, people have been able to identify the early developmental issues, the life experiences with parents that lead to depression. It also has enabled people to demonstrate that there are different qualities to these types of depression. Their symptoms, their expressions of depression are very different.

 Q: How does this affect therapy?

A: The treatment process has to be altered to some degree to focus on these issues rather than on the symptoms. It is a major change in not treating the disease or what we think we call the disease, but rather treating the individual and their experiences that make them feel depressed.

 We find that the most important aspect is the quality of the therapeutic relationship. It’s not the techniques that you use, whether it’s cognitive behavior therapy or interpersonal therapy or medication. The issue that determines outcome primarily is how the patient perceives the relationship.

 Q: Would this go against ideas that some mental illness is caused primarily by chemical malfunctions in the brain?

A: I assume there are biological processes involved. What those processes are and how they link into the psychological processes is an enormous and important area of investigation. I leave it to others to understand what possible biological mechanisms might be at work. I assume it works both ways. I assume that biology impacts on psychology and I assume that psychology impacts on biology.

 I think that the search for biological markers of psychiatric disorders is not a very productive research area, filled with all sorts of methodological problems. I am much more interested in the biological factors as they impact on psychological development. That is where the field has to move.

Q: So, that means that treating these diseases with medication alone will not necessarily resolve the issues?

A: Exactly. That’s what the data show. If you give someone medication, it reduces the symptoms temporarily but does not alter the life functioning and their capacities for adaptation. That only occurs in psychotherapy or primarily in psychotherapy. If you don’t establish a relationship with them, or show that you care about them, if you do not help revise their sense of themselves and a sense of the people who they want to love them, it is just going to reduce symptoms and will only last temporarily. Medication can be helpful and sometimes is essential but it primarily reduces symptoms and does not alter underlying psychological functioning and processes.