At the 2013 meeting of the American Academy of Child and Adolescent Psychiatry, Kyle Lapidus of Mount Sinai Hospital reviewed the literature from controlled studies on the efficacy of intravenous (IV) ketamine at a dosage of 0.5 mg/kg over a 40-minute infusion for adults with treatment-resistant depression (with consistent response rates of 50% or more), and suggested that intranasal ketamine may also be effective.
Ketamine is a strong blocker of the glutamate NMDA receptor. At high doses (6 to 12 mg/kg) it is an anesthetic, at slightly lower doses (3 to 4 mg/kg) it is psychotomimetic (causing psychotic symptoms) and is sometimes used as a drug of abuse, and at very low doses it is a rapidly acting antidepressant, often bringing about results within 2 hours. Antidepressant effects typically last 3 to 5 days, so the question of how to sustain these effects is a major one for the field.
Murrough et al. reported in Biological Psychiatry in 2012 that five subsequent infusions of ketamine sustained the initial antidepressant response and appeared to be well tolerated by the patients. Another NMDA antagonist, riluzole (used for the treatment of ALS or Lou Gehrig’s disease), did not sustain the acute effects of ketamine, and now lithium is being studied as a possible strategy for doing so.
The bioavailability of ketamine in the body depends on the way it is administered. Compared to IV administration, intramuscular (IM) administration is painful but results in 93% of the bioavailability of IV ketamine. Intranasal (IN) administration results in 25-50% of the bioavailability of IV administration, while oral administration results in only 16-20% of the bioavailability of IV administration, so Lapidus chose to study the IN route. He compared intranasal ketamine at doses of 50mg (administered in a mist ) to 0.5 ml of intranasal saline. Both were given in two infusions seven days apart. Lapidus observed good antidepressant effects and good tolerability. Papolos et al. had reported earlier that intranasal ketamine had good effects in a small open trial in treatment-resistant childhood onset bipolar disorder.
Editor’s Note: Further studies of the efficacy and tolerability of intranasal ketamine are eagerly awaited.
At a symposium on ketamine for the treatment of depression in children at the 2013 meeting of the American Academy of Child and Adolescent Psychiatry, David Brent, a professor at the University of Pittsburg, gave the opening talk on the fact that as many as 20% of adolescents who are depressed fail to improve, develop chronic illness, and are thus in need of alternatives to traditional treatment. Predictors of non-improvement include substance use, low-level manic symptoms, poor adherence to a medication regimen, low blood levels of antidepressants, family conflict, high levels of inflammation in the body, and importantly, maternal depression. In adolescents insomnia was associated with poor response, but in younger children insomnia was associated with a better response.
Brent suggested using melatonin and sleep-focused cognitive behavioral therapy for insomnia in youth, but not using trazodone (which is commonly prescribed). Trazodone is converted to a compound called Meta-chlorophenylpiperazine or MCPP, which induces anxiety and dysphoria. MCPP is metabolized by hepatic enzymes 2D6, and fluoxetine and paroxetine inhibit 2D6, so if trazodone is combined with these antidepressants, the patient may get too much MCPP.
Surprisingly and contrary to some data in adults about the positive effects of therapy in those with abuse histories, in the study TORDIA (Treatment of SSRI-Resistant Depression in Adolescents), if youth with depression had experienced abuse in childhood, they did less well on the combination of cognitive behavioral therapy and selective serotonin reuptake inhibitors (SSRIs) compared to SSRIs alone.
While the nutritional supplement folate (also known as folic acid or vitamin B9) can be useful for depression, there appears to be one instance when augmentation with regular folate could be counterproductive. In those with a transport defect associated with a MTHR (methyl tetrahydrofolate reductase) deficiency, folate can compete with l-methylfolate for uptake into the brain. Folate would thus limit the beneficial effects of l-methylfolate supplementation, which is required for this 15% of the population.
Severe malnutrition in the first year of life even when corrected for the rest of a person’s life leaves a legacy of permanent cognitive deficits, marked deficits in attention, and increases in depression, conduct disorders, and medical disorders compared to carefully matched controls. Jamina Galler, a researcher at Harvard Medical School, gave a plenary talk at the 2013 meeting of the American Academy of Child and Adolescent Psychiatry on the long-term effects of even short-term childhood malnutrition, including marasmus (calorie deficiency) and kwashiorkor (protein deficiency).
Galler’s studies followed three generations of people born in Barbados and observed the consequences of prior malnutrition, which was completely eliminated in Barbados by 1980. The consequences of malnutrition in the first year of life not only affected the first (G1) generation, but subsequently their offspring in the G2 generation who also suffered an excess of attention-deficit hyperactivity disorder, low IQ, and low annual income into adulthood. That is, the early malnutrition had transgenerational effects.
Malnutrition is a huge problem worldwide and is especially bad in sub-Saharan Africa and some parts of Asia. Globally, malnutrition accounts for 50% of the deaths of children under age five. However, even in the US hunger is a problem for one in four children, or about 16 million individuals, and the long-term consequences of hunger remain to be further studied.
Studies in animals indicate that early malnutrition has epigenetic effects that can be passed on to four future generations before they are reversed. Epigenetic effects refer to environmental factors that cannot change the sequence of DNA, but change how easily it is transcribed by adding or taking away acetyl and methyl groups on DNA and histones, the structures around which DNA is wound. Malnutrition (defined as 6–8% casein, a type of protein, in the diet instead of the normal 25%) in rodents affects cognitive abilities and blood pressure and can lead to diabetes, obesity, and other metabolic abnormalities. The next generation is also affected because a previously malnourished mother huddles too much with her offspring, and they become obese as a result of these poor parenting skills. The second generation also exhibits epigenetic changes in the prefrontal cortex (such as too few glucocorticoid receptors due to methylation of the glucocorticoid promoter) and fewer neurons in the hippocampus.
Editor’s Note: Other data indicate similar long-lasting epigenetic and transgenerational effects of other types of childhood adversity, such as verbal, physical, or sexual abuse. These findings in humans are also paralleled by findings in animals, and give strong credence to the idea that the environment can have long-lasting effects on neurobiology and behavior via epigenetic effects that can be superimposed on whatever genetic effects are inherited.
Data from this editor (Robert Post) and colleagues on verbal abuse in childhood is striking; this supposedly less severe form of abuse is still associated with a more difficult course of bipolar disorder and an increase in medical comorbidities. Thus, the experience of early abuse, even just verbal abuse, appears to have long-lasting consequences for psychiatric and medical health into adulthood.
Several studies in adults and children suggest that omega-3 fatty acid supplementation may have antidepressant effects. At the 2013 meeting of the American Academy of Child and Adolescent Psychiatry in October, Melissa DelBello, a professor at the University of Cincinnati, reported on a new study of omega-3 fatty acids in depressed children who had a parent with bipolar disorder. The children taking omega-3 fatty acids were more likely to improve than those taking a placebo, but the findings were only of marginal significance.
Cold-water fish are a good source of omega-3 fatty acids, and DelBello said salmon is by far the best in this regard. People who live in countries where fish is consumed in greater quantities are less likely to suffer from depression. Other sources of omega-3 fatty acids include shellfish, plant and nut oils, English walnuts, flaxseed, algae oils, and fortified foods.
The omega-3 fatty acids from fish are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), while the omega-3 fatty acids from plants are alpha-linolenic acid (ALA), which breaks down into EPA and DHA. All of these are anti-inflammatory, though one must consume much greater quantities of ALA to match the benefits of EPA and DHA. In contrast, omega-6 fatty acids, which are much more common in the typical American diet, are pro-inflammatory.
In DelBello’s study of 56 depressed children of a parent with bipolar disorder, the participants were randomized to either 1.8 g of omega-3 fatty acids (1.2 g of EPA and 0.6 g of DHA) or placebo (olive oil). Those who received the omega-3 fatty acids had a 55.6% rate of remission versus 34.5% for those who received placebo, but while the odds ratio of 2.4 favored the omega-3 fatty acids, the difference in remission rates was not statistically significant, likely because of the small size of the study. However, improvement on the Children’s Depression Rating Scale was significantly different across the two groups, with children taking omega-3s improving more. Omega-3 fatty acids are known to have an anticoagulant effect (preventing the clotting of blood), and four children in the study did have prolonged clotting times (but no clinical problems with bleeding).
Editor’s Note: Given the existing literature on omega-3 fatty acids and the trend in this study, omega-3s are worthy of consideration for the treatment and potentially for the prevention of depression in children. This later possibility is further suggested by findings from Australia that, when compared to placebo, omega-3 fatty acids significantly reduced the rate of conversion from prodromal (preliminary) psychotic symptoms to a full-blown diagnosis of schizophrenia.
In a 2013 study of children by Luby et al. in the Journal of the American Medical Association Pediatrics, poverty in early childhood was associated with smaller white and gray matter in the cortex and with smaller volume of the amygdala and hippocampus when the children reached school age. The effects of poverty on hippocampal volume were mediated by whether the children experienced stressful life events and whether a caregiver was supportive or hostile.
The children were recruited from primary care and day care settings between the ages of three and six, and were studied for five to ten years. They were initially assessed annually for three to six years and information on psychosocial, behavioral, and developmental dimensions were collected. Then the children took part in a magnetic resonance imaging (MRI) scan and continued annual assessments that included information such as whether the children experienced stressful life events.
Previous research has shown that poverty affects children’s psychosocial development and economic success in adulthood. This research shows that poverty also affects brain development. The findings suggest important targets for intervention that could help prevent these developmental deficits.
Evidence is growing that stressful events in childhood are associated with an earlier onset of bipolar disorders and a more difficult course of illness than in those who did not experience this type of adversity. Monica Aas and colleagues in Norway have found for the first time that emotional abuse in childhood, especially before age five, also increases risk of bipolar disorder. This study indicates that while bipolar disorder has a genetic component, environmental factors also play a role.
In Norway and France, the research group surveyed patients with bipolar disorder and people in the general population about childhood trauma, including emotional abuse, sexual abuse, physical abuse, emotional neglect, and physical neglect. Among the almost 800 participants, patients with bipolar disorder were twice as likely as control participants to have experienced multiple types of trauma. However, emotional abuse was the only factor specifically linked to bipolar disorder. People who were emotionally abused in childhood were more than twice as likely to develop bipolar disorder in adulthood. Moreover, the more severe the emotional abuse, the more likely it was that a child would go on to develop bipolar disorder.
Among the adults with bipolar disorder, emotional abuse and sexual abuse in childhood predicted younger age of illness onset, more suicide attempts, more rapid cycling, and greater proneness to depression. Emotional or sexual abuse were linked to the most suicide attempts, and sexual abuse was linked to rapid cycling.
More trauma in childhood was also linked to affective instability in adults. Aas’ research was presented at the 14th International Congress on Schizophrenia Research.
The psychiatric community has been preparing for the 2013 release of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) by the American Psychiatric Association for years. Each new edition of the manual reflects changing conceptions of illnesses and their diagnosis and treatment.
Tom Insel, the director of the National Institute of Mental Health (NIMH), the largest research organization in the world devoted to the understanding and treatment of mental disorders, caused a stir this past spring when he wrote in a blog post that the DSM-5 lacks validity and that patients deserve better.
The DSM-5 guidelines for diagnosis of mental disorders rely on descriptions of clusters of symptoms, and Insel suggested that new methods of diagnosis that rely on laboratory measure should be developed. The NIMH is launching a project called Research Domain Criteria (RDoC) to incorporate genetics, imaging, and other data in a new classification system for illnesses, and is re-orienting their funding toward projects that “look across current categories,” for example by including all patients in a mood disorder clinic rather than only those who meet DSM-5 criteria for major depressive disorder.
A major concern about this change at the NIMH, which funds much of the research that leads to Federal Drug Administration-approved treatments, is that it will diminish funding for treatment studies in specific diagnostic categories where research is already sparse, such as childhood onset bipolar illness. This may leave many children and adults without a sound evidence base upon which their doctors can base treatment decisions.
Under the NIMH’s new rubric, clinical treatment studies to collect comparative data and evidence-based treatment research would likely lose out to studies focused on the broad collection and identification of biomarkers and the pursuit of new treatment targets. Answering an important clinical question such as whether symptoms of childhood onset bipolar disorder respond to the same medications as oppositional defiant disorder (ODD) or disruptive mood dysregulation disorder (DMDD) might not be a high priority for study.
David Kupfer, chair of the APA’s DSM-5 Task Force, responded to Insel’s statement saying that while it would be great to identify biomarkers and genetic indicators for mental illnesses, “this promise, which we have anticipated since the 1970s, remains disappointingly distant.” Insel acknowledged in his statement that this is only the beginning of development of research domain criteria, and that “for the present” the DSM will continue to be used.
Electroconvulsive therapy (ECT) is an effective treatment for patients with treatment-resistant depression, but still many patients relapse after the treatment. Medications can prolong the period of remission, but even so, relapse rates have increased in recent decades (probably at least partly because ECT was once a standard initial treatment but is now only used with those patients with the most difficult-to-treat illnesses.) A 2013 meta-analysis by Jelovac et al. in Neuropsychopharmacology reviewed existing research on relapse and which medications might be able to best prolong remission after ECT.
The researchers analyzed 32 studies that each included at least 2 years of followup. In studies from the recent era in which patients received continuation treatment with medication following ECT, 51.1% of patients relapsed within a year, and the majority of those (37.7%) relapsed within the first 6 months after ECT. Among patients treated with continuation ECT, a similar proportion (37.2%) also relapsed within 6 months of the initial ECT treatment. In randomized controlled trials, treatment with antidepressants with or without lithium following ECT halved the rate of relapse within 6 months compared to placebo.
Even with continuing intermittent ECT treatment, risk of relapse remains high, especially within the first 6 months. The authors concluded that maintenance of wellbeing following ECT must be improved.
Editor’s Note: One possibility for prolonging remission is the more intensive continuation regimen using right unilateral ultrabrief pulse ECT suggested by Nordenskjöld et al. in the Journal of ECT in 2013. Continuation treatment with a combination of ECT and medication resulted in 6-month relapse rates of 29% (compared to 54% with medication alone) and one-year relapse rates of 32% (compared to 61%).
Finding an Appropriate Control
Comparing ketamine to placebo has challenges because ketamine produces mild dissociative effects (such as a feeling of distance from reality) that are noticeable to patients. At the 2013 meeting of the Society of Biological Psychiatry, James W. Murrough and collaborators at the Mount Sinai School of Medicine reported their findings from the first controlled trial of intravenous ketamine in depression that uses an active control, the short-acting benzodiazepine midazolam, which has sedative effects and decreases anxiety, but is not known as an antidepressant. On virtually all measures intravenous ketamine was a more effective antidepressant following 2 infusions per week.
These data help dispel one of the criticisms of intravenous ketamine, that studies of the drug have not been sufficiently blinded (when patients and medical staff are kept from knowing which patients receive an active treatment and which are in the placebo control group) and that the lack of an appropriate active placebo contributed to the dramatic findings about ketamine’s antidepressant effects. It now appears that these criticisms have been appropriately answered and that intravenous ketamine is highly effective not only in comparison to placebo but also to an active comparator.
This research was presented as a poster at the meeting and published as abstract #442 in the meeting supplement to the journal Biological Psychiatry, Volume 73, Number 9S, and was also published in the Archives of General Psychiatry in 2013.
Slowing Down Ketamine Infusions to Reduce Side Effects
Ketamine is commonly given in 40-minute intravenous infusions. Timothy Lineberry from the Mayo Clinic reported in Abstract #313 from the meeting that slower infusions of ketamine over 100 minutes were also effective in producing antidepressant effects in patients with treatment-resistant depression. Lineberry’s research group used the slower infusion in order to increase safety and decrease side effects, such as the dissociative effects discussed above. In the 10 patients the group studied, they observed a response rate of 80% and a remission rate of 50% (similar to ketamine’s effects with 40-minute infusions).
Family or Personal History of Alcohol Dependence Predicts Positive Response to Ketamine in Depression
Mark J. Niciu and collaborators at the NIMH reported in Abstract #326 that a personal or family history of alcohol dependence predicted a positive response to IV ketamine in patients with unipolar depression.
Ketamine Acts on Monoamines in Addition to Glutamate
Ketamine’s primary action in the nervous system is to block glutamate NMDA receptors in the brain. In addition to its effects on glutamate, it may also affect the monoamines norepinephrine and dopamine. Kareem S. El Iskandarani et al. reported in Abstract #333 that in a study of rats, ketamine increased the firing rate of norepinephrine neurons in a part of the brain called the locus coeruleus and also increased the number of spontaneous firing dopamine cells in the ventral tegmental area of the brain.
Editor’s Note: These data showing that ketamine increased the activity of two monoamines could help explain ketamine’s ability to induce rapid onset of antidepressant effects, in addition to its ability to immediately increase brain-derived neurotrophic factor (BDNF, important for long-term memory and the creation of new synapses) and to restore healthy mushroom-shaped spines on the dendrites of neurons in the prefrontal cortex.