Bipolar disease in children is more difficult to diagnose than in adults. It is a public health problem due to the severity and chronicity of the disease. The difficulty in diagnosing is related to the distinct manifestations of the disease during its early stages of development, whereas in adults it is associated to frequent comorbidity (Pavuluri et al., 2005). The dominant presence of bipolar disease in children is atypical, as the predominant signs are acute irritability, frequent chronic trajectory, and mixed symptoms of depression and mania.

It is important to evaluate comorbidity in children affected by bipolar disease, as it may imply anything from a diagnostic difficulty to a distinct therapeutic strategy requiring mixed treatment.

Sequels of comorbidity include increased prolongation of the disease, poorer diagnosis, and more resistance to treatment, which adds further costs to the disease.

The differential diagnosis versus comorbidity with Attention Deficit Hyperactivity Disorder (ADHD) is more complex, given that bipolar disease and ADHD have aspects in common with attention deficit, impulsiveness, motor hyperactivity and pressure to talk (Wozniak J, et al, 1995).
With the aim of shedding light on this issue, Faraone et al (1997) studied 140 children affected by ADHD. After stratifying the sample of ADHD children with and without bipolar disease, they noticed that, in both subgroups, there was a higher risk of ADHD among their relatives. However, only in children suffering from the two pathologies (ADHD and bipolar disease) the risk of bipolar disease in first-degree relatives was five times higher. This author suggests that comorbid attention deficit hyperactivity disorder with bipolar disease is familiarly distinct from other forms of ADHD, and may be related to pre-pubertal bipolar disease (Faraone et al (1997), Wozniak J, 1995).

Whether early or pre-pubertal bipolar disease is a distinct subtype of post-pubertal bipolar disease, or merely an earlier manifestation of the same disease, still needs to be ascertained (Weller EB, 2004). Given that early-onset bipolar disease presents distinct clinical and family risk aspects, some authors believe it is a subtype of bipolar disease.

When studying bipolar children and comparing them with hyperactive children, Geller pointed out that some symptoms that are characteristic of mania, such as elation, ideas of grandeur, reduced sleep, and sexual disinhibition were almost only noted in bipolar children. The symptoms found both on bipolar children and on children with ADHD were irritability, logorrhea, distractibility, and higher level of energy (Charfi, Cohen, 2005).

Hunt compared 3 groups of children ranging from 7 to 17 years of age. One of the groups presented irritability without elation, the other showed predominantly elation, and the third group was characterized by showing both (elation and irritability). He noticed that the group presenting irritability without elation was formed by children younger than in the other two groups, and that there were no other differences among the subgroups, namely in terms of severity of the disease, comorbidity, length of the disease, and family history of mania (Hunt et al, 2009). As the subgroup showing predominately irritability showed similar characteristics and similar family history of bipolar disease, like the subgroups presenting elation, we continue to consider episodic irritability in our diagnosis of paediatric bipolar disease.

In order to have a better understanding of the weight of irritability and hyperactivity in childhood bipolar disease, we will divide this pathology into restricted phenotype and extended phenotype. Restricted phenotype corresponds to children who totally fulfill the DSM-IV diagnosis criteria for hypomania or mania, including duration criteria and the presence of core symptoms of elevated mood and grandiosity. Extended phenotype corresponds to non-episodic chronic disease, which does not include core symptoms, but irritability, emotional lability, hyperactivity, impulsiveness, attention deficit, and aggressive choleric outbursts towards parents, peers and teachers (“affective storms”). This phenotype is core to this controversy, given that further research is necessary to ascertain if it really is a bipolar disorder that manifests itself during childhood, or if it refers to bipolar disorder prodrome symptoms pertaining to a distinct psychiatric disease presenting instability and mood changes. (Pavuluri et al.,2005).

The controversy about the relationship between bipolar disease and ADHD continues. Early-onset bipolar disease has a high percentage of comorbility, which requires

Paula Cristina Correia
Child and Adolescent Psychiatry Unit, Cova da Beira Hospital Centre
paula.correia@chcbeira.min-saude.pt

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