When it comes to the issues that trigger a bipolar episode, sleep disturbance is one of the likely causes. However, disruptions in the circadian rhythm (our 24 hour body clock) are thought to be particularly influential in the onset of rapid mood cycles associated with bipolar disorder in children.

Alexander Niculescu, from Indiana University School of Medicine, Indianapolis, and colleagues, recently reported variations in the regulatory gene RORB in some children diagnosed with bipolar disorder.

The study tested 292 children of which 152 were considered to have bipolar disorder. A further 140 children acted as a control group against which to compare the findings. Researchers found four variations in RORB in some of the children with bipolar disorder.

Decreased sleep has been identified as one of the factors that help to discriminate kids with bipolar disorder from those with attention deficit hyperactivity disorder (ADHD). Covering the story, Crystal Phend, staff writer at Meddpagetoday.com says that circadian rhythm abnormalities are suspected as one of the underpinnings of bipolar disorder in children. She quotes Niculescu as saying:

            "Clock genes in general and RORB in particular may be important candidates for further investigation in the search for the molecular basis of bipolar disorder."

Niculescu has cautioned that further studies are now needed to very these early findings.

Sources:

McGrath. C.L. et al (2009) Evidence for genetic association of RORB with bipolar disorder. BMC Psychiatry DOI: 10.1 186/1471-244X-9-70

Phend. C (2009) Circadian Clock Implicated in Kids' Bipolar Disorder. Medpagetoday.com. accessed November 13, 2009.