Developmental Psychopathology

What Is Developmental Psychopathology?

Pioneers of developmental psychopathology Sir Michael Rutter and Alan Sroufe offered that the field of developmental psychopathology is the study of the origins and course of individual behavioral adaptation, with special emphasis given to the how of developmental processes. Thus, the overarching questions asked by developmental psychopathologists include: How does psychopathology develop and how does this differ for individuals with different characteristics? How does a person’s  development  affect  psychopathology?  How does psychopathology affect a person’s development? We will briefly consider what is meant by psychopathology and then consider why it is critical that psychopathology and developmental be linked.

What Is Psychopathology?

Although a variety of conceptualizations are possible, what most scholars mean when they refer to psychopathology is abnormal behavior—what is variously called emotional/behavioral problems, psychiatric disorders, or psychological syndromes. While there remains debate regarding the intricacies of classification of psychopathology, there is much consensus and empirical support for what constitutes common syndromes of problems—depression, anxiety, autism, schizophrenia, and antisocial behavior are all generally accepted classes of behavior that are considered to be abnormal in and of themselves or when exhibited in excess. By abnormal we mean that these behaviors are maladaptive for either the individuals themselves or for society. By excess we mean a higher level of symptoms than exhibited by most individuals. Most people feel sad from time to time and many people occasionally break the law (i.e., drive too fast), but most people do not feel so sad and down that they cannot get out of bed for days on end, and most people do not repeatedly break the law and regularly violate the basic rights of others. It is the latter behavior, which violates societal norms, makes the person miserable, or renders one incapable of caring for oneself or others, that is defined as abnormal behavior, or psychopathology.

Importance of Development

Why is it so critical that inquiry regarding psychopathology be developmental? Historically, the two concepts have not been linked, yet development is central to what we now know about how psychopathology works. Normal development presents individuals with frequent challenges in every domain of life (behavioral, cognitive, emotional, social, physical), that once mastered constitutes growth—this is how babies become children and children become adults. For example, toward the end of the first year of life, infants become aware that there is a large and fascinating world out there that other people move around in. More importantly, they come to understand that they are people— thus, if they could move around, they could partake in the fun. However, infants must learn how to crawl,  stand, and eventually walk in order to fully interface with this stimulating environment. This is a challenge for an infant, who does not just wake up one morning capable of walking. The infant must try and fail repeatedly before mastering this new skill. Virtually all infants eventually master it and become capable walkers. However, some infants are very large or have low muscle tone and the challenge is more difficult for them than for other children, and thus they walk later than other children. It is likely that for many of these late walkers, other gross motor tasks may be somewhat difficult for them as well, and thus the next developmental challenge that comes along involving gross motor skills or large muscle strength may also be a larger hurdle for them than for other children. Current research and theory suggest that this is how psychopathology operates as well. Some children have or develop emotion regulation problems that make developmental challenges involving or requiring emotion regulation difficult for them. While such a child may eventually make it through a particular emotion-related challenge with support, this area will likely remain an area of vulnerability for the child, and when the next emotion-related developmental challenge arises, the child may have difficulty again. Mindfulness of developmental challenges can help parents or teachers anticipate hurdles for vulnerable children and provide preemptive support to help the child through subsequent challenges and minimize disruptions. Thus, there is much to be gained by including development in the conceptualization and study of psychopathology.

History of Developmental Psychopathology

While interest in description, classification, and treatment of psychological problems is not new, the field of developmental psychopathology is considered to have emerged primarily in the past three decades. This area of inquiry has its roots in several disciplines concerned with human behavior, including developmental psychology, clinical psychology, and psychiatry, and its links to these disciplines remain strong. However, it is now considered to be a unique field of science that has fundamentally changed child mental health research and policy.

To some degree, the field arose because of growing dissatisfaction with prevailing models of psychopathology that often left children out of the equation. The dominant diagnostic system (Diagnostic and Statistical Manual of Mental Disorders) gave almost no consideration to development in the guidelines set forth for diagnosis of psychopathology. It was assumed that children either did not experience true psychopathology or that if they did, it would look very much the same as psychopathology in adults. Several landmark publications and meetings have elaborated on this concern and/or offered solutions for how to improve the study of psychopathology. Thomas Achenbach’s 1974 textbook entitled Developmental Psychopathology introduced the idea that childhood psychopathology should be viewed as separate and distinct from adult psychopathology. Michael Rutter and Norman Garmezy are credited with charting the course of future inquiry for developmental psychopathology with their 1983 chapter on the topic in the Handbook of Child Psychology. Next, the 1989 Rochester Symposium on Developmental Psychopathology  brought  together  and  unified  a  diverse array of scholars whose work on psychopathology was explicitly developmental in scope and approach. Finally, the establishment of a journal in 1990 devoted exclusively to the topic, Development and Psychopathology, cemented the foundation of developmental psychopathology as a unique field unto itself. Developmental psychopathology has been an exciting and active area of research ever since.

Key Issues In Developmental Psychopathology

Diagnosis and Classification

The most basic question that developmental psychopathology is charged with answering is: What grouping of symptoms makes up a disorder? There are at least two approaches to answering this question: the top-down and bottom-up approaches. The top-down approach starts with the assumption that psychiatric diagnoses exist and, importantly, that we know what they are. Thus, the task at hand is to name the disorders and describe the set of symptoms that defines each one. The dominant nosology in American psychiatry was derived from a top-down approach: The Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV), is a catalog of hundreds of psychiatric disorders  used  by  clinicians  to  diagnose  patients. The bottom-up approach to classification starts at an entirely different place: It starts with an observation of all of the different types of symptoms that people report and uses statistical analysis to see how symptoms tend to group together to form syndromes. A major alternative to the DSM-IV can be found in these empirically based taxonomies, exemplified by the Achenbach system of empirically based assessment, where symptoms group into eight syndromes ranging from aggressive behavior to social withdrawal. Each of these approaches has strengths and weaknesses, and both are used currently. However,  debate  remains  about  which  approach  is most useful and accurate. Some developmental psychopathology researchers rely on the top-down DSMIV approach and study psychological disorders such as autism or panic disorder, while many opt for the bottom-up approach and focus on syndromes or groupings of symptoms, such as anxiety or antisocial behavior. At one level, the differences between disorder and syndrome are semantic—we hope that in the end we are all studying the same underlying problematic processes. At another level, however, our definitions shape and constrain the questions we ask. Thus, for example, studying only disorders may preclude the possibility of finding that the underlying biological mechanism of all psychopathology is the same and it is various cultural, social, and environmental factors that determine what form of psychopathology emerges. Alternatively, studying only syndromes could preclude the possibility of attending to qualitatively different groups of individuals whose functioning is so far outside the typical range that they need special research attention, such as persons with schizophrenia. For the purposes of this chapter, we will go with the first assumption: Both types of inquiry will lead to roughly the same place in the end, an understanding of maladaptive behavior in its many forms.

Risk, Resiliency, and Etiology

Much developmental psychopathology research is aimed at answering the question of etiology, or what causes psychopathology. Central to this line of inquiry are the concepts of risk and resiliency. What is risk? A developmental psychopathologist rarely asks the question “What causes disorder x?” expecting a simple answer. As with heart disease, there is no one cause. Some people appear to be vulnerable to developing heart disease because they are related to someone with heart disease—thus they are at genetic risk. However, being at genetic risk is not enough. It is a vulnerability that can be triggered by environmental stimuli, such as too much stress, being overweight, or having hypertension. The misconception that genes are destiny is fundamentally wrong—genes are probabilistic, not deterministic, when it comes to psychopathology. Most forms of psychopathology appear to operate in a very similar fashion to heart disease. Risk for psychopathology comes in many forms: genetics is one form, but histories of trauma, growing up in poverty, parental psychopathology, and interparental conflict also make some individuals more likely to develop certain forms of psychopathology than those without such a history.

What is resiliency? Resiliency can be defined as thriving despite having serious risk factors. Emmy Werner and Ruth Smith conducted an extensive 40year study of factors related to positive development in a cohort of almost 700 children born in 1955 on the Hawaiian island of Kauai. Eighty percent of the study children experienced multiple risk factors, including persistent poverty, parental alcoholism, parental psychopathology, and low parental education. Most of the children in this high-risk group experienced significant emotional, behavioral, academic, and/or occupational problems in childhood and beyond. However, 30% of this group showed none of these adverse life outcomes and in fact were thriving in childhood, adolescence, and adulthood. Werner and Smith documented  the  factors  that  made  these  children  stand out from the rest—the factors that protected these children. They identified five personal protective factors and five environmental protective factors. Personal protective factors were autonomy/social maturity, school competence, easy/extroverted temperament, self-efficacy, and good physical health. Environmental protective factors included maternal competence; emotional support in childhood, adolescence, and adulthood; and fewer stressful life events. Thus, competence and emotional support appear to be strengths that vulnerable children can draw on to be successful and healthy despite significant adversity.

Diathesis-Stress Model

A key theory espoused in much developmental psychopathology research and theory explicitly or implicitly is that of the diathesis-stress model. While this theory was originally developed as a theory specific to development of depression, it has broad applicability for a number of forms of psychopathology. Individuals develop diatheses (vulnerabilities) to psychopathology as a result of exposure to risk factors such as genetics, biological or environmental insults, child abuse/neglect, or poverty. Vulnerabilities come in a variety of forms ranging from innate temperamental characteristics to problematic thinking styles, ineffective regulation of emotions/arousal, and poor problem solving. For some individuals, these vulnerabilities lie dormant for a lifetime and they never develop psychopathology. For many though, the vulnerability becomes activated under challenging or difficult circumstances. Take, for example, cognitive vulnerability to depression. A large number of studies have found that individuals with depression tend to make errors in how they think about themselves, the world, and the future. They tend to believe that they are the cause of negative things that happen to them and that they play little role in the good things that happen to them. Individuals who have this thinking style are more likely to develop depression following a negative life event than individuals without this negativistic, self-defeating thinking style. This thinking style is believed to result from previous experiences that teach an individual that they are powerless or helpless, but it does not lead directly to depression except under stressful or difficult circumstances. Thus, the negative thinking style is the diathesis that lies in wait for a stressor potent enough to activate it and create a cascade of negative thoughts and feelings.

Nature Versus Nurture No  More

For years a battle has waged between those who believed that the causes of psychopathology were primarily genetic or biological and those who asserted that the environment played the major role in the etiology of psychopathology. The past two decades have seen a major shift whereby most psychopathologists recognize that genetics play some sort of role in the development of most types of psychopathology, and at the same time recognize that the environment is often what  determines  whether  a vulnerability  or  trait  is expressed, what form it takes, and how severe it is. Behavior geneticists emphasize that genes are probabilistic, not deterministic. A study by Avshalom Caspi and his colleagues aptly demonstrates this idea. They showed that the dopamine transporter gene (5-HTT), thought to be implicated in the development of depression, only predicted future depressive episodes in the presence of a major stressful life event. The absence of a main effect for the 5-HTT gene shows that indeed genes are not destiny. Some genes need to be activated, as do other diatheses. If there is no trigger for the gene, there will be no depression. Similarly, a study by Eric Turkheimer and colleagues at the University of Virginia showed that extreme poverty reduced the genetic influence on IQ to nonsignificance. In this case, the substantial and robust finding that approximately 70% of the variance in IQ scores can be explained by genetics received a noteworthy caveat: not in extreme environmental circumstances. Poverty has the power to suppress a child’s genetic IQ potential to such an extent that aspects of the environment explain more variance in the IQ score than does heritability.  These  two  studies  illustrate  the  power  of both the environment and genetics in determining psychological traits—in fact, these studies illustrate how woefully inadequate our explanations of psychopathology would be if we ignored either side of the equation.

Temperament

Infants are born with different styles of reactivity and self-regulation. Some babies are easy to soothe; regular in their eating, sleeping, and elimination habits; and quick to smile. Other babies are irritable and easily upset, irregular in their habits, and hard to engage in smiling or cuddling. Alexander Thomas, Stella Chess, and Herbert Birch observed that these characteristics, which they called temperament, appear at birth, remain stable over time, and place some individuals at risk for psychopathology. They categorized infants on nine dimensions of temperament ranging from activity level to adaptability, and they identified several groups of children based on how they scored on the various temperamental dimensions. Children were categorized as having “easy” and “difficult” temperaments. Thomas and colleagues found that difficult temperament may predispose a child to negative interactions with peers, parents, and teachers, but this is not inevitable—thus, difficult temperament is only a vulnerability for psychopathology, not an eventuality. Thomas and colleagues introduced the concept of “goodness of fit” to describe the fact that parenting styles and children’s temperaments may match well and promote optimal development or may clash and cause problems. Some parents are able to respond well to a “difficult” temperament and thus protect that child in the face of their temperamental vulnerability. Much of what is currently understood to be genetic risk may lie in these constitutionally based characteristic ways that individuals interact with the world beginning in infancy.

Comorbidity

Another chief concern of developmental psychopathology surrounds what we call comorbidity. This is the co-occurrence of two or more different types of psychological problems in the same individual at the same time. Thus, for example, an adolescent who meets diagnostic criteria for both major depressive disorder and conduct disorder at the same time is said to have comorbid depression and conduct disorder. A national survey found that 14% of U.S. adults surveyed met diagnostic criteria for at least three disorders at once. There are multiple theories to explain comorbidity, and many of them are specific to the particular diagnostic pairings. For example, anxious and depressive disorders are highly comorbid, and one theory to explain this phenomenon is that anxiety and depression have a common underlying cause: a propensity to experience negative emotions (negative affectivity). Another theory is that the distinction between anxious and depressive disorders is largely artifactual—that, for most individuals, anxiety and depression are simply facets of the same problem. Thus, prone individuals are likely to feel both nervous and sad at the same time. This is an important issue to sort out for anyone interested in the nature and course of psychopathology because, for example, there are different trajectories based on whether one has depression alone or in conjunction with another disorder. It also has treatment implications—comorbidity is related to more severe pathology and worse response to treatment. We know little about how best to treat depression in the face of another disorder— Which disorder takes precedence? Do you treat one before the other? Can you treat both at the same time? These questions remain largely unanswered.

Epidemiology

Documenting how many people of what age and gender meet diagnostic criteria for what forms of psychopathology is the charge of psychiatric epidemiologists. For policy makers to estimate treatment funding needs, we need reliable data on the prevalence of psychopathology (i.e., the number of people with a psychiatric disorder at any given time). We now know, for example, that close to 50% of Americans can be expected to meet diagnostic criteria for a DSM-IV psychiatric disorder at some point in their lifetime. We also know that anxiety and depressive disorders are more prevalent in females and that substance use disorders and antisocial personality disorders are more prevalent in males. In addition to basic questions about which disorders are most prevalent and for whom, developmental psychopathologists are particularly interested in determining the factors that influence prevalence rates. Thus, much research has attempted to address gender differences such as why women are prone to depression. The answer is multifaceted and as yet incomplete, but at this point stressful events appear to be a primary mechanism. Women are at heightened risk for experiencing a disproportionate number of stressful events/circumstances such as sexual abuse. Frequent stressful events repeatedly activate the brain’s stress response system (hypothalamic-pituitary-adrenal axis; HPA), which can cause the system to become dysregulated. Dysregulation in the HPA makes people more sensitive to future stressful events and to resulting depression. There may also be genetic vulnerabilities to dysregulation of the HPA, which further complicates understanding of this gender-based risk. This is another example of the exquisite interplay of genetic and environmental influences on psychopathology.

What Progress Have We Made?

Research has identified many factors that either place an individual at risk for or protect them against developing psychopathology. However, our remaining challenge is to begin finding the mechanisms of risk or the “hows” of risk. Mechanisms are often the factors that need to be targeted in intervention. For example, poverty is a substantial risk factor for the development of antisocial behavior, but not all individuals who experience poverty go on to develop psychopathology. Thus, the more we know about the factors that determine individual differences in response to poverty, the better able we are to target those most at risk with interventions. Here we review the research on antisocial behavior, one of the most common and persistent forms of psychopathology.

Antisocial behavior has received copious research attention, in part because of the social costs that result from delinquency and criminal activity. Longitudinal research  has  borne  extremely  useful  information for understanding the development of antisocial behavior, from how the symptoms change with age, to the factors that place children at risk, to the different subgroups of antisocial children. The DSM-IV lists oppositional  defiant  disorder  (ODD;  a  pattern  of  negativistic, oppositional behavior), conduct disorder (CD; persistent rule breaking), and attention deficit/hyperactivity disorder (ADHD; inability to inhibit inappropriate responses) as three distinct entities with different symptom groupings. However, the preponderance of data clearly suggests that ODD and CD are the same thing—that aggression and oppositionality are the early manifestations of the disorder and that persistent rule breaking is the later manifestation of the disorder, both reflecting age-specific misbehavior. In addition, the data suggest that the impulsive inhibition problems of ADHD may also be a component of the same disorder, although this is less well established than the ODD-CD link.

Terrie Moffitt’s studies following young children into adulthood were groundbreaking in showing that there are at least two distinct groups of antisocial youths. She found a relatively small group of antisocial children who were aggressive and antisocial at age 4 and remained so at every assessment until age 18 and beyond. This group of “life course persistent” antisocial children had multiple risk factors, including early aggression, impulsivity, poor peer relations, family adversity, and cognitive impairments. Their problems often progressed to adult criminality. The other major group in their study was a cadre of children who showed no antisocial behavior in childhood, but in adolescence began rule breaking at a level similar to the life course persistent group. This much larger group of “adolescence limited” antisocial children had none of the risk factors of life course persistent youths, but rather  had  poor  parental  monitoring  and  associated with antisocial peers. These teens tended to desist from delinquency in adulthood and rarely progressed to adult criminality. Individuals in this group did have some lingering mental health concerns in adulthood, however, such as impulsivity, substance abuse, financial problems, anxiety, and depression. There remain some important questions to be answered about delinquency in youths: Are there more than two groups of antisocial youths? Is ADHD part of a general disruptive syndrome? If so, how do we reconcile high genetic loadings for some forms of disruptive behavior (ADHD) and very low genetic loadings for other forms (adolescence limited antisocial behavior)?

What Don’t We Know Yet?

There are a few key areas in need of the attention of developmental psychopathology researchers in the next decades. The first concerns measurement issues. Despite the recognition that it is a problem to rely only on parents or children to tell us about their symptoms, reconciling the reports of multiple informants has proven to be challenging. Parent and child reports of children’s psychological symptoms tend to only be correlated at about 30%, indicating modest agreement. While a number of theories have been proposed to  understand  the  poor  cross-informant  agreement on key psychological constructs, we no longer assume that any one person will be 100% accurate. The leading theory currently is that different informants are privy to different aspects of an individual’s behavior; thus, each informant reports on the part that they are aware of. However, testing this theory has proven difficult and we still do not understand the mechanisms of informant disagreement—what predicts it, why it occurs,  and  what  variations  in  disagreement  mean vis-á-vis psychopathology.

The second area in need of future research attention involves gender differences in psychopathology. There are substantial gender differences in prevalence rates of some types of psychopathology. How much of this phenomenon is due to definitions that largely exclude one gender because they are unlikely to exhibit specific behaviors? Some researchers, for example, claim that the diagnostic criteria for conduct disorder are biased in favor of diagnosis for boys because of the overt aggressive nature of so many of the symptoms. These researchers assert that girls are antisocial as well, but that their aggression tends to be in the form of indirect or relational aggression. Thus, girls are less likely than boys to beat someone up, but they are likely to spread vicious rumors that serve to socially ostracize another girl. The current diagnostic criteria do not take such genderbased differences in behavior into account, which could account for gender-based differences in rates of conduct disorder, for example.

Finally, the brass ring of developmental psychopathology—etiology—remains out of grasp currently as we have much to learn about the causes of various forms of psychopathology. We do know that both genetics and the environment play a role in most forms of psychopathology and that these two things constantly interact, but we still do not understand the role of the mechanisms in the emergence of psychopathology. For example, if genetic vulnerability to depression operates indirectly through stress, then we need to search not for the depression gene, but rather the gene that makes individuals reactive to stress. Similarly, we need to better understand the role of temperament and other inherited characteristics in how an individual responds to environmental challenges. We need to understand the mechanisms of environmental indicators (i.e., how do they trigger genetic or other types of diathesis?). Finally, we hope to one day fully understand the lasting biological and psychological changes created by environmental risk events.

Implications Of Developmental Psychopathology

George Albee  has  written  extensively  about  the idea that individual treatment—in the form of medication or psychotherapy—can never change incidence rates of psychopathology. He asserts that the only way to stem the tide of psychopathology is through prevention. Even if there were adequate treatment services available for every individual with psychopathology (which there are not), the individualized treatment approach will always be a zero-sum game. The way to make things better is to take the public health approach and reduce incidence rates by reducing the pathogens (causes) of disease. Thus, for psychopathology, the known causes include poverty, trauma, and abuse, and the mechanisms of these risks include emotion regulation, problem solving, coping, academic preparedness, and the stress response system. Thus, prevention efforts have begun to target these risks and mechanisms in order to reduce incidence rates of psychopathology.

The contextual developmental psychopathology approach has also encouraged a communitarian perspective on treatment and prevention to emerge. Prevention scientists are calling for community-based interventions that reduce risk factors in an entire community. Thus, approaches to prevention that draw from Afro-centric community interventions and emancipatory education are exciting directions for community-oriented developmental psychopathologists. My colleagues and I, for example, have borrowed from the Afro-centric approach and are developing an empowerment prevention model that targets, builds, and channels resistance to race, class, gender, and sexuality oppression. With this contextual approach, we hope to use the best of developmental psychopathology research and theory to prevent delinquency in the most vulnerable, most treatment-resistant youths who currently see little hope for a future not marked by jail, failure, and a perpetual cycle of abuse and marginalization.

Thus, in addition to adding to our understanding of fundamental aspects of human behavior, developmental psychopathology has the promise of being transformative and making large-scale changes for the better mental health of all.

References:

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