Correlations versus causation?
A central methodological challenge in developmental psychopathology concerns establishing causal relationships. One way to establish causation is through a randomized controlled trial (RCT) in which individuals are randomly assigned to a condition/treatment or a control. Because individuals were assigned at random, there should be no other factor that explains group differences beyond the experimental manipulation. RCT’s are considered the “gold standard” in understanding causality; however, there are ethical and logistical concerns to designing experiments. To study the effects of living in poverty on developmental outcomes, it would not be ethical to take one child and randomly assign them to live in poverty and assign another to live in a wealthy home; thus, researchers must sample from different populations to compare effects, a method that does not truly assess causation. Similarly, researchers cannot intentionally design experiments to expose children to adverse experiences. However, researchers have utilized “experiments of nature” to understand how early adversity shapes developmental and neurobiological outcomes.
Person‐centered designs
Person‐centered research designs are used to examine the effects of risk/protective factors on subgroups of a sample, such as genotypes, personality, neighborhood, or other grouping factors and their developmental trajectories (Bergman & Magnusson, 1997). Advanced statistical strategies (growth mixture modeling, group‐based trajectory modeling) are used to study continuities and trajectories of behaviors as well as examine subgroups and how they change over time.
RESEARCH METHODOLOGIES
In this chapter, we have discussed how developmental psychopathology encompasses a wide range of disciplines and methods to answer our big questions. Improvements in brain imaging techniques and genetics have advanced research in these areas and development of psychopathology as a result. This section will briefly explain some of the methods discussed in later chapters.
Examining genetic factors
There are three main types of genetic studies that have increased our understanding of relationships between genes and behavior. The first is behavioral genetics, which separates variability in behavioral traits (e.g., aggression, anxiety) into heritability, environment, and Gene × Environment mechanisms. The second method of studying genetics is molecular genetics, which examines specific alleles, genetic markers, and gene expression patterns that are associated with psychopathology. Lastly, epigenetics refers to changes in gene expression due to environmental influences.
Neuroimaging
There are many available tools for capturing information about brain function and structure in children. Investigating brain function and structure helps us understand the neurobiological factors that contribute to current or later psychopathology risk. (e.g., Pinkham et al., 2008). Magnetic resonance imaging (MRI) is a technique that is widely used because it is non‐invasive and can capture properties about brain structure and function at all ages, even prenatally (Peterson, 2003). Structural MRI studies inform about brain anatomy and are used to examine the volume and shape of brain regions. Functional MRI (fMRI) studies provide information about activation in the brain, often in key regions, during rest or during specific tasks that require basic cognitive or emotional functioning. Electroencephalography (EEG) and magnoencephalography (MEG) are techniques that allow for the non‐invasive assessment of brain function. EEG and MEG provide highly accurate measurements of the timing of neural responses, but there is less spatial precision. Each neuroimaging technique offers specific advantages and disadvantages for studying neurobiological functioning across development.
Chapter Summary
This chapter provided an introduction to the developmental psychopathology framework. We first discussed the history of the developmental psychopathology model and discussed how it provided a new model for better understanding changes and individual differences in psychopathology across the lifespan. We provided an overview of several key tenets of the framework. Finally, we outlined various research designs and methodologies that have been employed to shed light on DP questions. An emphasis of this chapter is how the application of this framework to the study of psychopathology can be leveraged to support improved detection, diagnosis, prevention, and treatment.
Further Reading
1 Beauchaine, T. P., & Hinshaw, S. P. (Eds.) (2017). Child and adolescent psychopathology. Hoboken, NJ: John Wiley & Sons, Inc.
2 Cicchetti, D. (Ed.) (2016). Developmental psychopathology (vols 1–4). Hoboken, NJ: John Wiley & Sons, Inc.
3 Pollak, S. D. (2015). Developmental psychopathology: Recent advances and future challenges. World Psychiatry, 14(3), 262–269.
4 Sroufe, L. A. (2013). The promise of developmental psychopathology: Past and present. Development and Psychopathology, 25(4 pt. 2), 1215–1224.
5 Toth, S. L., & Cicchetti, D. (2010). The historical origins and developmental pathways of the discipline of developmental psychopathology. The Israel Journal of Psychiatry and Related Sciences, 47(2), 95–104.
Discussion/Essay Questions
1 How does studying normal and abnormal behavior inform understanding of developmental psychopathology?
2 Discuss how risk/resilience factors relate to psychopathology and provide an example of each.
3 Explain at least three levels of analyses that researchers study and how you would research a psychological disorder/concept at each level.
4 Discuss three research methods and at least one advantage and limitation of each method.
5 Discuss the nature vs. nurture debate and provide evidence for each side.
Glossary
Behavioral genetics separates variability in behavioral traits (e.g., aggression, anxiety) into heritability, environment.
Cross‐sectional design occurs when researchers do not sample variables over time. Data are collected at one time point.
Developmental milestones are indicators for how an individual has adapted and is functioning in their environmental context.
Developmental psychopathology is the study of the origins and course of individual patterns of behavior.
Epigenetics refers to changes in gene expression due to environmental influences.
Equifinality refers to the idea that many different pathways or early experiences may lead to the same outcome or condition.
Gene–environment interactions occur when both genes and the environment predict behavior or other outcomes. In a statistical model, GxE refers to when the effect of a gene depends on an environmental factor or the effect of the environment depends on genotype.
Heterotypic continuity is defined as stability of an underlying construct that is exhibited differentially across development; that is, different disorders predict one another over time (e.g., anxiety predicting later depression).
Homotypic continuity is defined as stability in the same or similar behavioral responses over time; that is, the same disorder predicts itself over time (e.g., earlier depression predicting later depression).
Macro factors such as family environment, school, peer interactions, community, and cultural context.
Magnetic resonance imaging (MRI) is a neuroimaging technique that is widely used because it is non‐invasive and can capture properties about brain structure and