Inflammatory Marker IL-6 is Elevated in People with Depression and Those with a History of Childhood Trauma

November 21, 2018 · Posted in Risk Factors · Comment 

verbal abuse of a child

In a 2018 article in the journal Psychiatry Research, researcher Ana Munjiza and colleagues reported that the inflammatory marker IL-6 was higher in 64 depressed people than in 53 non-depressed people, and that levels of IL-6 among people in the depressed group were significantly correlated with scores on a questionnaire in which participants reported traumas experienced in childhood. They reported more physical abuse, physical neglect, and emotional abuse.

Munjiza and colleagues indicate that trauma in childhood is a risk factor for depression in adulthood, as other researchers have suggested, and that inflammation could mediate the relationship between childhood adversity and depression.

Editor’s Note: IL-6 has been associated with antidepressant treatment resistance. IL-6 is secreted from white cells in the blood and from monocytes from the bone marrow in response to stress. It enters the brain and starts an inflammatory cascade that induces depressive behaviors. Animal studies have shown that if IL-6 secretion is blocked, depressive-like behaviors do not occur.

Another indicator of inflammation is CRP, and elevations in CRP have been associated with poor response to selective serotonin reuptake inhibitor (SSRI) antidepressants, and better response to the noradrenergic tricyclic antidepressant nortriptyline and the dopamine active antidepressant bupropion.

Treatments for depressed people with histories of childhood trauma may include psychotherapy, somatic therapies such as repeated transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS), and medication. More research is needed to determine the optimal treatment regimens for this subgroup of depression sufferers, including whether anti-inflammatory drugs could play a helpful role in preventing or treating depression. People with elevated inflammatory markers (such as IL-6, CRP, IL-1, or TNF-alpha) are likely to be better candidates for adjunctive anti-inflammatory treatments than those with normal or low baseline levels of inflammation.

A Calculator of Risk for Bipolar Disorder in Youth

January 3, 2018 · Posted in Risk Factors · Comment 

Daniella Hafeman of the University of Pittsburgh described a risk calculator for predicting an individual’s risk for bipolar disorder, which is available at www.pediatricbipolar.pitt.edu. Possible factors included in the risk calculation include a parent’s early age of onset of bipolar disorder, mood shifts early in life, a child’s anxiety or depression symptoms, later affective mood shifts, and new onset of subthreshold mania.

Editor’s Note: A “poor man’s” assessment of risk can also be of help to a family or clinician. There are four components. The first is genetic. Having one parent with bipolar disorder is a potent risk factor, and can be further magnified if the other parent also has a mood disorder. If three or more first degree relatives or three or more generations of first degree relatives have a mood disorder, this further increases risk four- to six-fold.

Perinatal vulnerability is another factor. Beyond these genetic vulnerabilities, a history of maternal toxoplasmosis or a viral infection during pregnancy, or the infant being noticeably underweight at birth can contribute to bipolar risk.

Childhood adversity also contributes to vulnerability to early onset of bipolar illness. A history of psychosocial stress in the child’s early years, such as abuse or abandonment, can be an added risk factor.

Prodromal or preliminary symptoms are also a risk factor. The development of an anxiety or depressive disorder, a disruptive behavioral disorder, or a bipolar not-otherwise-specified diagnosis (BP-NOS, used to describe manic symptoms of short duration) further increases risk. In studies by David Axelson and Boris Birmaher, 50% of children with an initial diagnosis of BP-NOS developed full-blown bipolar I or II illness upon several years of followup if there was a family history of bipolar disorder. About one-third converted to full bipolar disorder if there was no family history of bipolar disorder.

Thus, if a child has three or all four types of risk factors, their risk would be substantial. In this case, one might consider attempts at prevention. This could include a good diet rich in omega-3 fatty acids, regular exercise, joining a school sports team, developing good sleep habits, playing a musical instrument, and engaging in something akin to family focused therapy. Family focused therapy emphasizes psychoeducation, good communication skills, and problem solving. Attending to and treating parents’ symptoms and building a support system for both parents and the child can also help.

While these endeavors are not a guarantee to prevent the onset of more severe illness, they are all health-promoting in general and have few downsides.

Traumatic Events in Childhood Linked to Shorter Telomeres

September 12, 2017 · Posted in Risk Factors · Comment 

verbal abuse of a child

Telomeres are bits of DNA at the end of chromosomes that protect the DNA as it replicates. Shorter telomeres have been linked to aging and increases in multiple types of medical and psychiatric disorders. A 2016 article in PNAS, the Proceedings of the National Academy of Sciences of the United States of America, reported that cumulative life adversity and particularly stressful or traumatic events in childhood, predict shorter telomere length.

The study by Eli Puterman and colleagues included 4,590 individuals from the US Health and Retirement Study who reported stressful events that had experienced. A single experience of adversity was not linked to short telomeres, but lifetime cumulative adversity predicted 6% greater odds of having shorter telomeres. This result was mainly explained by adversity that occurred in childhood. Each stressful or traumatic event in childhood increased the odds of short telomeres by 11%. These were mostly social or traumatic experiences rather than financial stresses.

Brain Volumes Affected by Type and Timing of Childhood Abuse

December 13, 2016 · Posted in Risk Factors · Comment 

age when abused affects brain volume

Maltreatment during childhood has been linked to brain changes and mental illness. In a study by researcher Carl M. Anderson and colleagues that was presented at the 2016 meeting of the Society of Biological Psychiatry, maltreatment at particular ages was statistically linked to deficits in the size of certain brain areas in young adulthood.

The brain areas under examination are critical for the regulation of emotion and behavior, and this research suggests that early experiences can stunt their development, perhaps through  altered production of synapses or via the synaptic pruning process that occurs during preadolescence. The details, summarized below, are perhaps less important than the overall finding that maltreatment in childhood affects brain volume, and this effect varies based on the timing and type of maltreatment. Abuse and neglect earlier in life affected the left side of the brain, while later maltreatment affected the right side.

Severity of physical abuse at age 3 affected the volume of the ventromedial prefrontal cortex in women. Physical abuse at ages 3 and 8 in men affected left ventromedial prefrontal cortical volume, while later abuse at ages 7 and 12 predicted volume of the right side.

In women, dorsal anterior cingulate area on the left was predicted by physical abuse at age 5 and by emotional neglect at ages 7 and 11. Later emotional neglect at ages 15 and 16 and physical abuse by a peer at age 10 was associated with smaller right dorsal anterior cingulate. In men, smaller left dorsal anterior cingulate area was predicted by physical neglect at age 2 and emotional abuse by a peer and witnessing abuse of a sibling at ages 5 and 10, and right area by physical neglect at age 12.

Link Between Childhood Trauma and Difficult Course of Bipolar Disorder Clarified

November 9, 2015 · Posted in Genetics, Risk Factors · Comment 

Trauma in childhood linked to course of bipolar disorder

A collaboration between Norwegian and French researchers led by Bruno Etain has clarified the pathway by which childhood trauma is linked to worse outcomes among people with bipolar disorder. The researchers, who presented their work in a poster at the 2015 meeting of the Society of Biological Psychiatry, replicated earlier findings by this editor (Robert Post) that patients who experienced trauma as a child had a more adverse course of bipolar disorder. Etain and colleagues found a link between childhood trauma and an earlier age of onset of bipolar disorder, rapid cycling, suicide attempts, and cannabis misuse.

The researchers identified more than 550 patients with bipolar disorder, who answered questionnaires about their history of bipolar disorder and childhood trauma. Their DNA was also analyzed, and the researchers found that the effect of childhood trauma on age of onset was mediated by the presence of common genetic variants in proteins related to stress (the serotonin transporter) and immune function (Toll-like receptors). They also found that the traits of mood lability (or moodiness) and impulsivity mediated the effects of trauma on clinical outcomes.

The lasting epigenetic effects of child maltreatment and adversity noted in the above abstract are consistent with a large literature showing more epigenetic effects in these individuals than in controls. While genetics are important, the impact of the environment is also substantial.

Molecular Biology of Depression

October 1, 2015 · Posted in Neurobiology, Risk Factors · Comment 

molecular biology of depressionDysregulation of the brain in early life can have lasting effects, and the effects of stress and depression can also accumulate. At the 2015 meeting of the Society of Biological Psychiatry, researcher Huda Akil explained that behavioral pathology can “take on a life of its own, leading to deteriorating course of illness and treatment resistance.” She illustrated how preclinical work in animals can help clarify the molecular biology of depression and develop new targets for therapeutics.

Early Life Experiences are Key

Akil discuss studies of rodents in which she used new molecular genetic techniques to increase the number of glucocorticoid receptors in the hippocampus early in life (prior to weaning). Glucocorticoid receptors mediate the effects of the stress hormone cortisol in people and corticosterone in rodents. More receptors help shut off cortisol secretion after a stressful event. People with post-traumatic stress disorder (PTSD) have high levels of glucocorticoid receptors while people with depression have low levels, leading to over-secretion of cortisol in depression.

The increased glucocorticoid receptors led to a long-term increase in anxiety behaviors and response to stimulants. When Akil carried out the same manipulation on rats that had already been weaned, it had no long-lasting effects, showing that there is a vulnerability window for some long-lasting effects on behavior.

CLOCK Genes and Circadian Rhythms

Akil also studied CLOCK genes in rodents. These genes, including BMAL-1, Per 1, Per 2, and Per3, play a role in circadian rhythms, and their transcription induces these 24-hour cycles. In rodents who were induced into a depression-like state, the CLOCK genes were dysregulated and did not correspond to normal circadian rhythms. These data show that depressive states can induce changes in CLOCK genes and circadian rhythms. Others have shown the converse, that abnormal CLOCK genes can induce behavioral abnormalities including mania-like behaviors.

Fibroblast Growth Factor

Levels of fibroblast growth factor 2 (FGF2) in the hippocampus are low in people with depression. In rodents, FGF2 inhibits anxiety. Decreases in FGF2 are seen in the hippocampus of animals in a depression-like state following repeated defeat by a larger animal. It appears that FGF2 is an endogenous antidepressant (i.e. one that is produced by the brain). When the rodent brain is manipulated to eliminate FGF2, the animals become anxious.

In addition, animals bred to have high stress, low social responsivity, and resistance to new learning also have low FGF2. Treatment with FGF2 reversed these behavioral abnormalities and also increased the production of new neurons. For the stressed rats, receiving FGF2 on their second day of life increased new neuron production, decreased anxiety, decreased proneness to social defeat stress and increased the bonding hormone oxytocin in the amygdala into adulthood.

FGF2 had no effect on rats bred for low stress and high social responsivity, indicating that it only worked for the rats that needed it. Akil compared FGF2 to “personalized medicine for rats.”

Defeat stress affects the way genes are transcribed, and FGF2 was able to reverse one of these specific transcriptional effects, suggesting it could potentially ameliorate some of the long-lasting effects of stress and depression.

The Human Brain

Akil also studied the brains of people who had died of depression, bipolar disorder, or schizophrenia. In bipolar disorder, the nucleus accumbens, the reward center of the brain, was enlarged.

In contrast, Akil described the brains of those people who had died with depression as being “low on fertilizer.” That is, they showed less cell growth, less production of new neurons, more abnormalities in cell shape, and more cell death. Akil said that by the time someone is severely ill, the pathology is all over the brain. The changes Akil saw in the brains of people who were depressed are also consistent with data indicating that several neuroprotective factors, including BDNF and VEG-F, are low in the frontal cortex and the hippocampus of depressed people (while BDNF is high in the nucleus accumbens).

Low Oxytocin Linked to Depression in Moms

September 21, 2015 · Posted in Risk Factors · Comment 

postpartum depression

At a panel at the 2015 meeting of the Society of Biological Psychiatry, researcher Andrea Gonzales described her team’s study of mechanisms related to postpartum depression and the bonding hormone oxytocin. In the study of 26 women at eight months postpartum, the team examined whether there were connections between a mother’s levels of oxytocin at baseline and after interacting with her child, her mood symptoms, and whether she was mistreated in childhood.

Those women who scored low on a history of maltreatment in childhood had bigger increases in oxytocin in their blood and saliva after interacting with their children. Those with high trauma scores but low levels of depression also saw big boosts in oxytocin after seeing their children. Those women who had both a history of trauma in childhood and current depressive symptoms did not get as big a boost of oxytocin after interacting with their children.

Gonzales and colleagues concluded that postpartum depression is linked to dysregulation of oxytocin levels, and that a history of trauma in the mother’s childhood can make this worse.

The researchers hope that these findings may make it easier to identify which women are at risk for postpartum depression, and that they may point to possible treatments in the future.

Postpartum depression is a problem for about 13% of mothers in the year after they give birth, and mother-child bonding may be disturbed if a mother is depressed. One way to foster better bonding between a depressed mother and her newborn is to use video feedback. A mother views video of herself interacting with her child while a trained professional helps her identify opportunities for greater physical contact.

Early Life Stressors Lead to Lifetime Increase in Inflammation in Mice

March 9, 2015 · Posted in Risk Factors · Comment 

mother mouse and pups

Stressors in early life can contribute to the risk of developing mood disorders. Given that many treatments for mood disorders work by blocking the serotonin 5-HT transporter, Nicole Baganz and colleagues designed a study to see whether an early life stressor, in this case maternal separation, would affect immune processes that in turn affect serotonin signaling.

In this study as in many before it, mice that were removed from their mothers exhibited behaviors that resembled human anxiety and depression. They were also found to have elevated messenger RNA for several inflammatory cytokines (including IL-1beta and IL-6) in their brain and blood. Mice that had a gene for the interleukin-1 receptor (IL-1R) removed exhibited neither the depressive behavioral effects nor the changes in cytokine levels following maternal separation, showing that the IL-1R gene plays a necessary role in the signaling process that leads to this type of depression. Levels of the stress hormone corticosterone in the blood did not differ in the mice with and without the IL-1R gene.

The researchers concluded that early life stressors can cause lifelong changes in inflammatory cytokine levels in mice.

Young Rats That Witness Maternal Abuse Show Depression-Like Behavior in Adulthood

March 5, 2015 · Posted in Risk Factors · Comment 

rat mother and baby

Rodents that are subjected to social defeat (being overpowered by a bigger, more aggressive animal) develop a syndrome that resembles human depression—they avoid social interaction, lose interest in sucrose, and do less exploring of new places or other animals. A recent finding showed that even witnessing the social defeat of a peer was enough to bring about the depressive behaviors. The same researchers, led by Samina Salim, recently found that young rats (aged 21–27 days) that witnessed their mother go through the trauma of social defeat showed depression-like behavior themselves as adults (at age 60 days).

The rats saw their mothers defeated by the larger rat every day for seven days. As adults, those who witnessed this abuse exhibited depression-like behavior compared to rats of the same age and gender that had not witnessed abuse. The depressive rats gave up more quickly on a test of forced swimming. Male rats showed great depression-like behavior than female rats.

It has been estimated by the American Psychological Association that 15.5 million children in the US witness physical or emotional abuse of a parent (usually their mother). Children who witness domestic violence often show symptoms of post-traumatic stress disorder (PTSD). This rodent research may lead to a better understanding of the consequences of witnessing trauma in childhood, and potential treatments that could help.

Editor’s Note: These data show that rats have something like empathy, and that the psychological aspects of stress (including verbal abuse in humans and witnessing another’s abuse in rodents) may have profound and lasting consequences on behavior.

Maternal Childhood Adversity Associated with Low Infant Birth Weight

February 17, 2015 · Posted in Genetics · Comment 

mother and infant

In a study of the effect on infant health of a mother’s experience of adversity in childhood by researcher Deborah Kim and colleagues, both adversity in childhood (such as physical abuse or the loss of a parent) and stress during pregnancy were associated with low infant birth weight and lower gestational age at birth.

Among 146 women enrolled in the study, 58.2% percent scored a 0 on the Adverse Childhood Experience Questionnaire (ACE), 24% scored a 1, and 17.8% scored a 2. Those who scored higher on the ACE also scored higher on a scale measuring perceived stress. A score of 2 or higher on the ACE was associated with lower gestational age at birth, indicating infants born prematurely. Greater stress during pregnancy was associated with lower gestational age at birth and lower infant birth weight. When potential confounding demographic factors were removed from the analyses, ACE scores of 2 or higher were still associated with lower infant birth weight, while perceived stress was no longer associated with either low birth weight or gestational age.

Childhood adversity is associated with increases in inflammation and multiple adverse medical consequences in adults. The researchers called childhood adversity a “significant predictor of poor delivery outcomes” for women.

Editor’s Note: This research shows that a mother’s health and earlier life stressors could have an adverse effect on her child.

Childhood adversity leaves behind a residue of neuroendocrine and neuroclinical alterations that can persist into adulthood. Many are mediated by epigenetic changes, consisting of small chemical marks that attach to DNA and the histones around which it is wrapped.

In addition to these neurobiological alterations mediated by epigenetic effects, there is new evidence that some epigenetic marks can be passed on to the next generation via a mother’s egg or a father’s sperm. Thus, either directly or indirectly, parents’ adverse life experiences can influence the health of their offspring.

Next Page »