Neurobiology of Child Neglect/Abuse: Nemeroff Lecture Notes

I had the opportunity to attend the Warren Neuroscience Lecture presented by Dr. Charles Nemeroff in Tulsa, OK on June 2, 2015.

Dr. Nemeroff has been an international leader in research in mood and anxiety disorders. His recent focus has been on the effects of adverse childhood environments on risk for adult mood and anxiety disorders. 

Here are my notes that summarize some of the key points from his lecture.

Introduction:

• Stress is an important factor in understanding depression
• Early life stress is a risk factor for later adult depression
• Genes account for a significant portion of the variation in risk following stress exposure
• Brain systems that regulate emotions are disrupted during episodes of major depression

Psychiatry research slowed by complexity of brain, multiple cell types, complex heterogeneous disorders. But we are beginning to understand the key role genes play in a variety of key disorders. Genetic factors account for 65% of bipolar disorder variance, 50% of schizophrenia variance and around 35% of variance in major depression.

Early childhood abuse and neglect is common. Recent surveys estimate prevalence rates for each of the following:

• Physical abuse 15-28% of general population in U.S.
• Sexual abuse in 11-21% 
• Emotional abuse in 11-36%
• Parental divorce or separation in 25%

Early childhood abuse and neglect has multiple effects in neurobiology and later adult mood and anxiety disorder risk:

• Increased adult cerebral spinal marker of stress known as corticotrophin releasing factor (CRF)
• Increase serum ACTH and cortisol
• Increase inflammatory markers  such as interleukin-6
• Decreased cerebral spinal fluid oxytocin that may impair social function and bonding with children
• Reduced brain cortex thickness and hyperactivy amygdala response
• Increased adult PTSD and depression
• Increased adult rates of substance abuse
• Increased risk of suicidal behavior and completed suicide

There is a growing body of evidence that ten or more genes influence vulnerability to childhood abuse and neglect including genes regulating the HPA axis, serotonin function and a gene known as FKBP5. These genetic effects may interact with environmental stresses to reduce or amplify stress vulnerability. Stress may be viewed as a teratogen that influences genetic features through epigenetic and gene regulation effects.

For clinicians there are important treatment implications:

• Major depression in the context of moderate to severe childhood abuse is less responsive to medication or to psychotherapy intervention
• Childhood abuse and neglect in bipolar disorder is linked to early onset, greater severity and poor treatment response.

During the discussion following the lecture Dr. Nemeroff noted the importance of population-based efforts to reduce societal levels of exposure to child abuse and neglect including:

• Early education with teacher training to look for evidence of abuse/neglect
• Increased training for primary care physicians treating infants/children
• Increased training and funding for social services that evaluate and treat children referred for child abuse/neglect
• Increased detection and surveillance for sexual predators
• More research in the treatment of sexual disorders including pedophilia. There is almost no NIH funding in this area and little research interest and activity.

Below I have added citations featured in the presentation to allow readers with more interest to delve into some of the primary research studies.

Image is this post is "PBB Protein CRH image" from Wikipedia chapter on CRH. Image by ProteinBoxBot.  Licensed under Public Domain via Wikimedia Commons  

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Heim C, Newport DJ, Heit S, Graham YP, Wilcox M, Bonsall R, Miller AH, & Nemeroff CB (2000). Pituitary-adrenal and autonomic responses to stress in women after sexual and physical abuse in childhood. JAMA, 284 (5), 592-7 PMID: 10918705

Heim C, Mletzko T, Purselle D, Musselman DL, & Nemeroff CB (2008). The dexamethasone/corticotropin-releasing factor test in men with major depression: role of childhood trauma. Biological psychiatry, 63 (4), 398-405 PMID: 17825799

Binder EB, Bradley RG, Liu W, Epstein MP, Deveau TC, Mercer KB, Tang Y, Gillespie CF, Heim CM, Nemeroff CB, Schwartz AC, Cubells JF, & Ressler KJ (2008). Association of FKBP5 polymorphisms and childhood abuse with risk of posttraumatic stress disorder symptoms in adults. JAMA, 299 (11), 1291-305 PMID: 18349090

Saveanu, R., & Nemeroff, C. (2012). Etiology of Depression: Genetic and Environmental Factors Psychiatric Clinics of North America, 35 (1), 51-71 DOI: 10.1016/j.psc.2011.12.001