ADHD and BSD co-occurrence linked to reduced global functioning
MedWire News: The co-occurrence of attention-deficit hyperactivity disorder (ADHD) and bipolar spectrum disorder (BSD) in children is associated with reduced global functioning and increased symptom severity compared with either disorder alone, research shows.
"Both BSD and ADHD manifest symptoms of impulsivity, hyperactivity, and irritability, with impairments in social relations, increased substance use, and underachievement," explain Eugene Arnold (Ohio State University, Columbus, USA) and colleagues.
But they add that studies investigating the co-occurrence of these disorders and effects on symptom severity, functioning, and other variables have produced conflicting results.
To investigate further, the researchers studied data on 707 children, aged 6-12 years, who participated in the Longitudinal Assessment of Manic Symptoms study.
The team used the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime version to screen the participants for BSDs and a variety of other assessments were used to confirm the diagnosis. The presence of ADHD was assessed according to DSM-IV criteria.
The children were also assessed for global functioning using the Children's Global Assessment Scale (CGAS), and for symptom severity using the Clinical Global Impressions Scale-Severity (CGI-S).
In total, 421 children met criteria for ADHD alone, 45 had BSD alone, and 117 had both ADHD and BPSD. The remaining 124 children had neither disorder. The researchers note in the journal Bipolar Disorders that the co-occurrence of ADHD and BSD (16.5%) was slightly less than would be expected by chance (17.5%).
They found that there was no significant difference in mean age at mood symptom onset between children with both BSD and ADHD and those with BSD alone, at 6.68 and 6.88 years, respectively.
However, children with both disorders had greater symptom severity and poorer global functioning than those with BSD alone or ADHD alone, with CGI-S scores of 4.03 versus 3.69 and 3.31, respectively, and CGAS scores of 50.03 versus 54.45 and 55.15, respectively.
Children with both ADHD and BPSD also had a higher mean number of other comorbidities, at 3.27, followed by those with ADHD alone, at 2.57, and those with BSD alone, at 1.87.
Nevertheless, children with BSD alone were just as likely to have been hospitalized as children with BSD and ADHD. Those with ADHD alone had the lowest hospitalization rates.
Arnold and team conclude: "The high rate of BSD in ADHD reported by some authors may be better explained as a high rate of both disorders in child outpatient settings rather than ADHD being a risk factor for BPSD.
"Co-occurrence of the two disorders is associated with poorer global functioning, greater symptom severity, and more additional comorbidity than for either single disorder."
By Mark Cowen