A new 4-year longitudinal study of children and their families found inattention, one of the components of attention deficit hyperactivity disorder, to predict symptoms of depression 4 years later. The study was published in the Research on Child Adolescent Psychopathology.
The share of population suffering from depression has risen consistently during the last 80 years in the United States. Costs of treating depression are currently assessed at $210 billion per year. This increase in prevalence of depression is accompanied with earlier age of onset with 2% of children and up to 8% of adolescents meeting diagnostic criteria for major depressive disorder. Another 5-10% of youth are experiencing subclinical symptoms of depression.
A number of factors in children have been suspected to be linked with the early onset of depression. These include attention deficit hyperactivity disorder (ADHD), executive functioning (various psychological functions such as memory, behavior control, capacity for goal-oriented behavior), rumination and others.
To study the possible links between ADHD and executive functioning with depression, Michelle C. Fenesy and Steve S. Lee conducted a study of 216 children (67% boys) and their families over a 4-year period. The study was divided into three waves i.e., time points when the data were collected from the participants.
At the start of the study, in wave 1, researchers interviewed parents and teachers of children participating in the study to assess the presence of ADHD in children. The children also completed a battery of different cognitive psychological tests that assessed their executive functioning and the presence of ADHD symptoms. ADHD was assessed through its two key components – inattention and hyperactivity/impulsivity.
Two years later, in the second wave, researchers assessed the academic achievement of children through tests focusing on reading and mathematics skills and by obtaining an assessment of children’s behavior from their teachers (Child Behavior Checklist and the Teacher Report Form).
Teachers and parents also provided for each child an assessment of whether it is accepted, rejected or ignored by peers (Dishion social preference Scale, assessment of social problems). Researchers expected that academic achievement and social problems might have a role in the relationship between factors measured in the first wave and depression.
Two years after wave 2, in the third wave, children, now teenagers, completed a battery of psychological tests assessing the presence of depressions symptoms.
The results showed that children who scored high on inattention, one of the key components of ADHD had higher levels of depression symptoms four years later. This link remained even after accounting for parental education and income. Higher levels of inattention were linked to worse executive functioning, but executive functioning by itself was not associated to depression when inattention was accounted for. For the most part, academic achievement and social problems were not associated with symptoms of depression assessed two years later.
The study highlighted an important link between one aspect of ADHD and depression. Finding this link with four years of difference is an important achievement. However, authors note that a higher number of participants would allow the associations between variables to be studied better, given the statistical analysis techniques used. Noting that at wave 3, only one participant had completed pubertal development, authors suggest that future replications of their study should plan assessments of depression after puberty, the period that sees a dramatic increase in psychopathological symptoms in the population.
The title of the study was “Childhood ADHD and Executive Functioning: Unique Predictions of Early Adolescent Depression“.