Studies of primates suggest that the amygdala plays an important role in the development of anxiety disorders. Researcher Ned Kalin suggested at the 2015 meeting of the Society of Biological Psychiatry that the pathology of anxiety begins early in life. When a child with anxiety faces uncertainty, the brain increases activity in the amygdala, the insula, and the prefrontal cortex. Children with an anxious temperament, who are sensitive to new social experiences, are at almost sevenfold risk of developing a social anxiety disorder, and later experiencing depression or substance abuse.
A study by Patrick H. Roseboom and colleagues presented at the meeting was based on the finding that corticotropin-releasing hormone (CRH) plays a role in stress and is found in the central nucleus of the amygdala (as well as in the hypothalamus). The researchers used viral vectors to increase CRH in the central nucleus of the amygdala in young rhesus monkeys, hoping to determine what impact increased CRH has on a young brain. Rhesus monkeys and humans share similar genetic and neural structures that allow for complex social and emotional functioning.
Roseboom and colleagues compared the temperaments of five monkeys who received injections increasing the CRH in their amygdala region to five monkeys who received control injections. As expected, the monkeys with increased CRH showed increases in anxious temperament. Brain scans also revealed increases in metabolism not only in the central nucleus of the amygdala, but also in other parts of the brain that have been linked to anxiety, including the orbitofrontal cortex, the hippocampus, and the brainstem, in the affected monkeys. The degree of increase in amygdala metabolism was directly proportional to the increase in anxious temperament in the monkeys, further linking CRH’s effects in the amygdala to anxiety.
At the 2015 meeting of the Transcranial Magnetic Stimulation Society in May, researcher Stephanie Ameis discussed the dearth of medication studies in children, particularly for depression but also for schizophrenia and autism spectrum disorders, which share the symptom of impaired executive functioning, which can include skills such as planning and problem solving.
Ameis noted that in a literature review, there were a total of 1046 controlled pharmacological treatment studies in adults compared to only 106 in children, which reflects a relative absence of treatment knowledge, especially for depression (where there were 303 studies in adults versus only 17 in children) and bipolar disorder (where there were 174 studies of adults and 24 of children).
Ameis then reviewed the few studies of rTMS for depression in young people. She identified several series with only a total of 33 children and adolescents who had been treated with rTMS. She is beginning to study rTMS in patients with high-functioning autism (40 patients aged 16 to 25 have been randomized in her study). Ameis also described a 2013 study of rTMS in which patients with schizophrenia showed improved performance on a test of working memory published by Mera S. Barr and colleagues in the journal Biological Psychiatry. Ameis cited this as a rationale for studying rTMS’s effect on cognitive performance in people with autism.
At the 3rd Annual Meeting of the Transcranial Magnetic Stimulation Society, Canadian researcher Frank MacMaster discussed his study of repeated transcranial magnetic stimulation (rTMS) in 50 children with depression. RTMS is a non-invasive procedure in which an electromagnetic coil is placed against the side of the forehead and magnetic pulses that can penetrate the scalp are converted into small electrical currents that stimulate neurons in the brain. The study was designed to identify biomarkers, or characteristics that might indicate which patients were likely to respond to the treatment. All of the patients received rTMS at a frequency of 10 Hz. Using magnetic resonance spectroscopy (MRS) technology, MacMaster found that children who responded well to rTMS treatment had low levels of the neurotransmitter glutamate at the beginning of the study, but their glutamate levels increased as their depression improved. Children who didn’t improve had higher glutamate levels at the beginning of the study, and these fell during the rTMS treatment.
MacMaster hopes that glutamate levels and other biological indicators such as inflammation will eventually pinpoint which treatments are likely to work best for children with depression. At the meeting, MacMaster said that in Canada, only a quarter of the 1,200,000 children with depression receive appropriate treatment for it. Very little funding is devoted to research on children’s mental health, a serious deficit when one considers that most depression, anxiety, attention deficit hyperactivity disorder (ADHD), bipolar disorder, oppositional behavior, conduct disorder, and substance abuse begins in childhood and adolescence, and early onset of these illnesses has been repeatedly linked to poorer outcomes.
Editor’s Note: The strategy of identifying biomarkers is an important one. MacMaster noted that this type of research is possible due to the phenomenal improvements in brain imaging techniques that have occurred over the past several decades. These techniques include magnetic resonance imaging (MRI) to a resolution of 1 mm; functional MRI; diffusion tensor imaging (DTI), which can depict the connectivity of white matter tracts; and spectroscopy, which can be used to identify chemical markers of neuronal health and inhibitory and excitatory neurotransmitters, and analyze membrane integrity and metabolic changes. These methods provide exquisite views of the living brain, the most complicated structure in the universe. The biomarkers these techniques may identify will allow clinicians to predict how a patient will respond to a given treatment, to choose treatments more rapidly, and to treat patients more effectively.
In a longitudinal study of 1,037 people born in Dunedin, New Zealand in 1972 and 1973, most participants with attention deficit hyperactivity disorder (ADHD) in adulthood did not have the disorder as children. The study by Terrie E. Moffitt and colleagues in the American Journal of Psychiatry is the first prospective longitudinal study to describe the childhood of adults with ADHD.
When the study participants were children, about 6% were diagnosed with ADHD (mostly males). These children also had comorbid disorders, neurocognitive deficits, multiple genes associated with risk for ADHD, and some life impairment when they reached adulthood.
In adulthood, about 3% of the participants had ADHD (roughly equal between men and women), and 90% of these participants had no history of ADHD in childhood. The participants with ADHD in adulthood also had substance dependence and life impairment, and had sought treatment for the disorder. The researchers were surprised to find that these participants with adult ADHD did not show neuropsychological deficits in childhood, nor did they have the genetic risk factors associated with childhood ADHD.
If the findings of this study are replicated, researchers will have to rethink the current classification of ADHD as a neurodevelopment disorder that begins in childhood, and begin to determine how adult ADHD develops.
Editor’s Note: Before the publication of this article, most investigators (including this editor Robert M. Post) thought that virtually all ADHD in adulthood evolved from the childhood disorder, and if it did not begin in childhood, the diagnosis was suspect. I still believe the ADHD that appears in adulthood in patients with bipolar disorder is likely attributable to residual depression and anxiety or hypomania and that more concerted treatment of the patient to full remission will often result in much better attention, concentration, and ability to follow through and stay on task.
Relatively little attention has been paid to the children of a parent with bipolar disorder, who are at risk not only for the onset of bipolar disorder, but also anxiety, depression, and multiple other disorders. These children deserve a special focus, as on average 74.2% will receive a major (Axis 1) psychiatric diagnosis within seven years.
New research published by David Axelson and colleagues in the American Journal of Psychiatry describes a longitudinal study comparing children who have a parent with bipolar disorder to demographically matched children in the general public. Offspring at high risk for bipolar disorder because they have a parent with the disorder had significantly higher rates of subthreshold mania or hypomania (13.3% versus 1.2%) or what is known as bipolar disorder not otherwise specified (BP-NOS); manic, mixed, or hypomanic episodes (9.2% versus 0.8%); major depressive episodes (32.0% versus 14.9%); and anxiety disorders (39.9% versus 21.8%) than offspring of parents without bipolar disorder. Subthreshold episodes of mania or hypomania (those that resemble but do not meet the full requirements for bipolar disorder in terms of duration) were the best predictor of later manic episodes. This finding was observed prospectively, meaning that patients who were diagnosed with manic episodes during a follow-up assessment were likely to have been diagnosed with a subthreshold manic or hypomanic episode during a previous assessment.
The study included 391 children (aged 6–18) of at least one bipolar parent, and compared these to 248 children of parents without bipolar disorder in the community. The participants took part in follow-up assessments every 2.5 years on average, for a total of about 6.8 years. Each follow-up assessment included retrospective analysis of symptoms that had occurred since the previous assessment.
In addition to having more subthreshold manic or hypomanic episodes; manic, mixed, or hypomanic episodes; and major depressive episodes, the high-risk children also showed more non-mood-related axis 1 disorders, including attention deficit hyperactivity disorder (ADHD), disruptive behavior disorders, and anxiety disorders than the children of parents without bipolar disorder. Axelson suggested that monitoring for these symptoms may help with early identification and treatment.
Children with a bipolar parent were diagnosed with bipolar spectrum disorders at rates of 23% compared to 3.2% in the comparison offspring. Mean age of onset of mania or hypomania in the high-risk offspring was 13.4 years. Of those offspring who had a manic episode, more than half had the episode before age 12, with the earliest occurring at age 8.1.
Compared to previous studies of children of parents with bipolar disorder, this study found that the mean age of onset of manic or hypomanic episodes was younger, possibly because other studies did not include young children. Another new finding was that major depressive episodes were risk factors for mania and hypomania but did not always precede the onset of mania or hypomania in the high-risk offspring.
Parents of children who are at high risk for developing bipolar spectrum disorders should be aware of the common precursors to mania—subthreshold manic or hypomanic symptoms and non-mood disorders—and make sure that clinicians assess for these symptoms and differentiate them from the symptoms of depression or other disorders.
Editor’s Note: In Axelson’s study, 74.2% of the offspring of a bipolar parent suffered a major (Axis I) psychiatric disorder. However, 48.4% of the offspring from the comparison group of community controls also had an Axis 1 psychiatric disorder. These high rates of illness and dysfunction indicate the importance of monitoring a variety of symptom areas and getting appropriate evaluation and treatment in the face of symptoms that are associated with impairment in both high risk children and in the general population.
One way of doing this is for parents to join our new Child Network, a study collecting information about how children at risk for bipolar disorder or with symptoms of bipolar disorder are being treated in the community and how well they are doing. Parents rate their children on a weekly basis for depression, anxiety, ADHD, oppositionality, and mania-like symptoms. Parents will be able to produce a longitudinal chart of their children’s symptoms and response to treatment, which may assist their child’s physician with early detection of illness and with treatment. See here for more information and to access informed consent documents.
A new study finds that omega-3 fatty acid supplementation improves attention in boys both with and without attention deficit hyperactivity disorder (ADHD). The study by Dienke J. Bos and colleagues in the journal Neuropsychopharmacology included 40 boys (aged 8–14) with ADHD and 39 demographically matched controls. Participants were given 10 g per day of margarine supplemented with either omega-3 fatty acids (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)) or placebo.
The children who received EPA/DHA supplementation showed improvements in attention (as rated by parents) compared to those who received placebo. Improvement was greater in the children with ADHD. Supplementation did not affect cognitive control or brain activity on functional magnetic resonance imaging (fMRI). Those boys who received omega-3s showed higher DHA levels on followup.
A new study from Finland suggests that low vitamin D levels in childhood and adolescence can predict atherosclerosis, or hardening of the arteries, in adulthood. The study, by Markus Juonala and colleagues in the Journal of Clinical Endocrinology & Metabolism, included 2,148 people whose vitamin D levels were measured at ages 3–18. They were checked for atherosclerosis at ages 30–45. Those participants with the lowest levels of vitamin D in their youth were at much higher risk for thickened arteries as adults. The finding was independent of other cardiovascular risk factors such as smoking, high blood pressure, poor eating, lack of exercise, and obesity.
Editor’s Note: While it is not yet clear if low vitamin D levels directly cause the development of atherosclerosis, it is important to maintain sufficient vitamin D in childhood for a host of reasons, including strong bones. Children with sufficient vitamin D levels are more likely to have normal moods and behavior than those deficient in vitamin D.
New research shows that expressions of maternal warmth following corporal punishment do not reduce children’s anxiety, and may even increase it.
The study by Jennifer E. Lansford and colleagues was published in the Journal of Clinical Child & Adolescent Psychiatry. The researchers interviewed over a thousand children aged 7–10 and their mothers about what type of physical punishment occurs in their family, and about anxiety and aggression in the children. They followed up again after one and two years. The study took place in eight countries: China, Colombia, Italy, Jordan, Kenya, the Philippines, Thailand, and the United States.
In general, corporal punishment increased anxiety in the children, while maternal warmth decreased it. How warmth and physical punishment interacted depended on the country. Anxiety increased over time in families where the mothers were high on both corporal punishment and warmth. Lansford and colleagues wrote that it might be “simply too confusing and unnerving for a child to be hit hard and loved warmly all in the same home.”
The researchers suggest that parents use nonphysical ways to promote desirable behavior in their children, including putting younger children in time-out and requiring teenagers to participate in activities that help others.
Studies have found that when a depressed mother’s symptoms remit, her children are less likely to show psychiatric symptoms. A new study by Myrna M. Weissman and colleagues in the American Journal of Psychiatry randomized 76 mothers to treatment with escitalopram, bupropion, or a combination of the two, and assessed the impact of the mothers’ treatment on their 135 children (aged 7–17).
There were no significant differences in the mothers’ symptoms or remission, but children’s depressive symptoms and functioning improved more if their mothers received (only) escitalopram. Only in that group was a mother’s improvement associated with her children’s improvement.
Mothers in the escitalopram group reported greater improvement in their ability to listen and talk to their children compared to the mothers in other groups, and the children of the mothers in the escitalopram group reported that their mothers were more caring.
Children of mothers with low negative affect improved significantly, while children of mothers with high negative affect only improved if their mothers were in the escitalopram group.
The authors suggest that for a mother’s improvement to help her children’s symptoms, her anxious distress and irritability must be reduced, and these may be better targeted with escitalopram than bupropion.
Enduring stressful life events in childhood can affect children long-term. Children who experience neglect can show increased levels of cortisol, a stress hormone. Family interventions can reduce these levels, and a new study shows that the impact of these interventions can be lasting. The study, by Kristin Bernard and colleagues in the journal JAMA Pediatrics, included 115 children whose families had been referred to Child Protective Services after allegations of neglect. After an incident of neglect in early childhood, the families received either an experimental intervention called ABC (focused on increasing parental nurturance to child distress, increasing synchronous interactions, and decreasing frightening parental behavior) or a control intervention (which provided educational information about child development). When the children reached preschool age about three years later, the researchers collected the children’s cortisol levels at waking and bedtime on three different days.
The children whose families received the ABC intervention had more typical cortisol levels than those whose families had received the control intervention. The ABC children had higher morning cortisol, with a steeper decline throughout the day, compared to a more blunted cortisol rhythm in the control group children. These patterns resembled differences in the two groups observed three months after the initial intervention. The authors concluded that the ABC intervention has long-term effects on children’s physiological stress system, helping them maintain health and adjustment.