65 Interestingly, the diagnostic frequency of ADHD was about three times as high with children of bipolar parents compared to the offspring of controls, suggesting that ADHD can be associated with an increased risk for bipolarity of family members, but also that BD increases the risk of ADHD in the family.58-65 The prevalence rate of roughly 22% for the diagnosis of ADHD among relatives of patients with ADHD and comorbid BD is about seven times as high as that for the relatives of controls (3%), whereas relatives of patients with ADHD alone had diagnostic rates for pure ADHD approximately five times as high as relatives Inhibitors,research,lifescience,medical of controls.67 The prevalence rates of BD were found to be

much higher in relatives of patients with ADHD and comorbid BD. In contrast to

the rates on ADHD prevalence, no significantly enhanced risk for bipolarity was found regarding relatives of patients with ADHD without bipolar symptoms.66 Finally, the prevalence of BD without comorbid ADHD was not found to be higher in relatives Inhibitors,research,lifescience,medical of patients with ADHD or ADHD and comorbid BD.66 As Faraone et al point out, these findings are far from being unquestionable; this can be put down to low prevalence rates Inhibitors,research,lifescience,medical of pure BD as a single diagnosis without comorbid ADHD. This in turn tends to support the hypothesis that BD and ADHD possibly share underlying psychopathological mechanisms.58 Faraone and colleagues58 recommend two pathways towards addressing the issue of selleck products familiarity in BD and ADHD. The first possibility might be that certain risk alleles for BD and ADHD can be independently transmitted, thus influencing the high comorbidity of BD and ADHD.58 Secondly, BD and ADHD may share a common Inhibitors,research,lifescience,medical underlying psychopathological entity which can be transmitted as a complex differing from BD and ADHD, but still sharing Inhibitors,research,lifescience,medical some of the ADHD and BD symptoms.58 Faraone et al have undertaken a study on ADHD and comorbid BD prevalence in relatives of ADHD patients with and without BD including controls and their relatives. why The indication was that relatives

of controls tended to have no diagnosis of ADHD and comorbid BD, whereas the ADHD/BD prevalence in relatives of patients with the same diagnoses was 12% and the prevalence of ADHD/BD in relatives of patients with ADHD was 2%.65 According to Faraone et al, these findings provide preliminary evidence that ADHD and BD could cosegregate through generations as a symptom complex, thus sharing a potential underlying psychopathophysiological mechanism.58 Summary Epidemiological data suggest a high comorbidity of ADHD with BD symptoms, whilst each disorder seems to increase the risk of the other, a factor supporting the hypothesis that these two disorders are interrelated in terms of common underlying psychopathological properties.