an effect on the incidence of more mild forms, such as Asperger syndrome. The benefits were seen in those women who had been taking folic acid for 4 weeks before conception and continued to take the supplement during the first 8 weeks of pregnancy.
Irritability is common in unipolar depression. Emslie suggested that if a child’s irritability is severe and the child destroys objects and denies being irritable, bipolar disorder might be likely. Irritable unipolar depressed children will generally acknowledge being irritable.
Emslie reported that 96% of youth in his randomized placebo-controlled studies of selective serotonin reuptake inhibitor antidepressants (SSRIs) recovered from their unipolar depression, but 46.6% relapsed. Those children with residual depressive symptoms were at double the risk for relapse into a depression compared to those who remitted completely. In those without residual depressive symptoms, there were no relapses if the children stayed on their medications.
Children were excluded from Emslie’s study if they had a positive family history of bipolar disorder, and perhaps because of this, very few participants switched into mania with antidepressants.
MORAL: Treat to remission and stay on the antidepressants associated with the remission. This has previously been found to be important for adults as well. (Emslie added that he would advise that a child stay on an antidepressant for at least a year after a remission was achieved, and longer if the child had difficulties in academic performance or relationships at school.)
Children with unipolar major depression who had a few manic symptoms at a subsyndromal level had poorer outcomes in Emslie’s study. The presence of subsyndromal manic symptoms in bipolar depressed adults is a risk factor for increased switching into mania when antidepressants are added to a mood stabilizer.
Comorbid substance abuse is another risk factor for poor outcome in childhood depression.
In two posters presented at the 2012 meeting of the American Academy of Child and Adolescent Psychiatry, a research group led by Kiki Chang reported that increased severity of manic symptoms is associated with increased size of the amygdala (especially the right amygdala) in adolescents who are at high risk for developing bipolar disorder.
The amygdala is a crucial area for emotion regulation. The increasing size, either with more manic symptoms or as patients with bipolar disorder age into adulthood compared to normal volunteer controls (as we describe in the article on brain imaging at far left) could reflect increased use of the amygdala in bipolar disorder.
The increased amygdala size could be linked to increased emotion dysregulation, or it could be a compensatory mechanism in which the amygdala works harder to exert better emotion control.
Experience-dependent neuroplasticity describes a phenomenon in which the volume of a brain area increases as it gets more use (like a muscle that grows when it gets more exercise). One interesting example in which this may occur is London taxi drivers, who have larger hippocampi than the general public. (The hippocampus is responsible for some of the brain’s spatial recognition abilities.) This could be explained in two different ways. The discrepancy in size between the hippocampi of taxi drivers and of the general population may exist because the taxi drivers’ brains change over the course of their careers via experience-dependent neuroplasticity, or it may exist because those with excellent spatial recognition abilities and bigger hippocampi choose to become taxi drivers.
At the 2012 meeting of the American Academy of Child and Adolescent Psychiatry (AACAP), Carrie E. Bearden presented data from a study that predicted conversion to psychosis in at-risk youth (those who have prodromal symptoms or a particular genetic mutation that leads to psychosis) by observing white matter abnormalities.
Bearden found that the degree of white matter abnormality seen during magnetic resonance imaging (MRI) was proportional to the degree of cognitive deficit in pat