A metanalytic review of 17 longitudinal studies reported that people who had conduct disorder, defiant disorder, or disruptive disorder as children were more likely to develop depression later in life. The study was published in Clinical Psychology & Psychotherapy.
Depression or major depressive disorder is one of the most common mental disorders. Approximately 5% of people worldwide suffer from it. The World Health organization ranks it as the third largest cause of burden of disease in the world. It is projected to rank first by 2030.
Symptoms of depression include continuous low mood or sadness, low self-esteem, feeling tearful, hopeless, helpless, guilt-ridden and others. Depression is often associated with substance abuse and having suicidal thoughts.
Previous studies have indicated that externalizing emotional disorders in children may predict later difficulties in different areas. Externalizing disorders are disorders characterized by problematic behaviors directed externally, towards the social environment, such as aggression, impulsivity, rule breaking, inattention (e.g., in school) and others.
These include conduct disorder (children has difficulty following rules and behaving in a socially acceptable way, sometimes even being hostile and physically violent), oppositional defiant disorder (children are uncooperative, defiant and hostile towards others), and disruptive disorder (children disrupt activities around them – at home, at school or with peers).
The authors of this study wanted to better understand the relationship between these childhood disorders and later depression. They searched databases of scientific publications — PubMed, Psych Info, and Google Scholar — for longitudinal studies (i.e., studies that followed participants for a longer period of time and recorded developments) conducted on children or people younger than 18, that assessed depression, conduct disorder, oppositional defiant disorder, and disruptive disorder. They only included studies that followed study participants for at least 2 years.
The search resulted in a final list of 17 studies. The researchers used these to conduct two metanalyses. The first metanalysis explored the link between conduct disorder in childhood and later depression (eight studies). The second metanalysis focused on the link between either oppositional defiant disorder or disruptive disorder in childhood and later depression (nine studies).
The first metanalysis showed that conduct disorder was found to be a risk factor of later depression in all eight studies. Depending on the study, children with conduct disorder were between 1.4 and 16.4 times more likely to develop depression later in life than children without conduct disorder.
When oppositional defiant disorder and disruptive disorder were considered, people who had these disorders in childhood were between 1.4 and 14.4 time more likely to develop depression later than people without these disorders.
“Our findings indicate a strong relationship of conduct disorder, oppositional defiant disorder and disruptive disorder in children to the later development of depression. We did not find a single study selected by our a priori criteria which did not show a significant result in the hypothesized direction. The meta-analyses were, of course, strongly positive. As our findings were strong and did not conflict with previous literature in the area, we feel our hypotheses were supported,” the study authors concluded.
The study made a valuable contribution to systematizing scientific knowledge about early risk factors of depression. However, it also has limitations that need to be considered. Notably, as authors themselves write, it is not certain that the three childhood disorders chosen were the best measures of maladaptive coping with stress in childhood. Additionally, the studies were very heterogenous with regard to the groups studied, assessment methods used, and the time periods during which participants were followed.
The study, “Childhood maladaptive coping mechanisms and the subsequent development of depression”, was authored by James Reich and Alan Schatzberg.