A follow-up study of young adults who were diagnosed years earlier with childhood-onset bipolar disorder suggests that their cognitive flexibility—in many cases already impaired at the time of diagnosis—may continue to deteriorate, along with other aspects of cognition, as they advance into young adulthood.

The study, appearing in European Child & Adolescent Psychiatry, also suggests that some young adults who were diagnosed with bipolar disorder as children and who have impairments in cognitive flexibility are more likely to spend time as young adults in a depressed state and to have suicidal thoughts.

Cognitive flexibility is the ability to adapt one's thinking and behavior to changes in the environment—including the ability to learn or adapt when presented with rewards or punishment.

The inability to learn or adapt in such situations has been linked with the difficulty depressed people have in experiencing or seeking pleasure, a symptom called anhedonia. Cognitive flexibility deficits are also thought to generate or reinforce feelings of helplessness in the face of a threat or challenge, thus potentially contributing to depression as well as to suicidal thinking.

A team led by Daniel P. Dickstein, M.D., of McLean Hospital and Harvard University, a 2015 BBRF Independent Investigator, 2006 Young Investigator, and winner of the 2010 BBRF Klerman Prize, and Heather A. MacPherson, Ph.D., of Brown University, studied 49 young adults with bipolar disorder who had previously been enrolled in a Brown-based study called COBY of childhood-onset bipolar disorder. In the current study they also enrolled 44 matched control subjects in order to make comparisons.

All of the participants were given tasks to perform which measured their responsivity to rewards and punishments. While prior data had indicated that like adults, children diagnosed with bipolar disorder have impaired cognitive flexibility, there had been no prior studies assessing whether these impairments changed as affected children made the critical transition to young adulthood. Nor had any past study tried to determine if any such changes in cognitive flexibility are predictive of the future course of bipolar disorder.

Children aged 7-17 had taken part in the initial COBY study, and in this study ranged in age between 18 and 30. Thirty-four of these participants had a diagnosis of BD-I, defined by the researchers as bipolar disorder marked by distinct mood episodes—depression and/or mania or hypomania (a less intense form of mania). Another 15 COBY participants had a diagnosis of BD-NOS ("bipolar disorder not otherwise specified") which is assigned to those who have bipolar symptoms that are "sub-threshold" or in which no pattern has yet emerged.

The researchers found that young adults who had been diagnosed as children with BD-I—i.e., with already established episodes of depression and/or mania-hypomania—experienced greater cognitive flexibility deficits than participants who had been diagnosed with BD-NOS or healthy controls. Also, those with childhood-onset BD-I demonstrated impaired executive functioning compared to both other groups, and impaired spatial working memory compared to controls only.

The researchers called particular attention to their finding that cognitive flexibility deficits in the BD-1 group were associated in young adulthood with amount of time depressed and with suicidal thoughts.

Taken together, this suggests to the team that cognitive flexibility deficits may be an important prognostic indicator and intervention target for those with childhood-onset BD-I, "as this deficit appears to endure into young adulthood and is associated with worse prognosis for depressive symptoms and suicidal ideation."

Evidence in childhood of cognitive flexibility deficits, the team says, could help predict future depressive symptoms, and may be related to under-sensitivity in reward processing and reinforcement (i.e., anhedonia). "Patients with BD-I thus may benefit from therapeutic strategies specifically targeting reward processing and positive reinforcement, such as behavioral activation and problem solving."

These strategies are part of existing psychotherapies for childhood-onset bipolar disorder, the team notes, and may be supplemented "to enhance the learning/uptake of these skills, such as cognitive remediation and specialized psychosocial treatments like Mindfulness-Based Cognitive Therapy."

The team also points to the potential utility of specialized interventions for suicidality, such as Dialectical Behavior Therapy, especially for children diagnosed with BD-I.