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Cerebrum
The Dana Forum on Brain Science
Volume 2 ■Number 4 ■Fall 2000
Cerebrum
©2000 Dana Press
The Dana Foundation
www.dana.org
About the Author:
Martin H. Teicher, M.D., Ph.D., directs the Developmental Biopsychiatry Research
Program and is chief, Laboratory of Developmental Psychopharmacology, at
McLean Hospital. His recent studies have been of the neurobiological effects of
childhood mistreatment and the neurobiology of attention deficit/hyperactivity
disorder.
ARTICLE
Wounds That Time Won’t Heal: The Neurobiology of Child Abuse
Martin H. Teicher
Neuropsychologist Teicher reveals the alarming connections scientists are discovering between
child abuse—even when it is psychological, not physical—and permanent debilitating changes
in the brain that may lead to psychiatric problems. The discoveries are a wake-up call for our
society, but they may also hold hope for new treatments for abused children and the adults that
they become.
We easily understand how beating a child
may damage the developing brain, but what
about the all-too-common psychological abuse
of children? Because the abuse was not physi-
cal, these children may be told, as adults, that
they should just “get over it.”
But as developmental neuropsychiatrist
Martin H. Teicher reveals, scientists are dis-
covering some startling connections between
abuse of all kinds and both permanent debil-
itating changes in the brain and psychiatric
problems ranging from panic attacks to post-
traumatic stress disorder. In these surprising
physical consequences of psychological trauma,
Teicher sees not only a wake-up call for our
society but hope for new treatments.
We know that the abuse or
neglect of children is tragically
common in America today.
Nor are most of us surprised when studies
point to a strong link between the physical,
sexual, or psychological maltreatment
of children and the development of psychi-
atric problems. To explain how such
problems come about, many mental health
professionals resort to personality theories
or metaphors. Perhaps the child’s adaptive
or protective mechanisms have become
by Martin H. Teicher, M.D., Ph.D.
Wounds That Time Won’t Heal:
The Neurobiology of Child Abuse
counterproductive or self-defeating in the
adult. Perhaps childhood abuse has
arrested psychosocial development, leaving
a “wounded child” within the adult.
Although such explanations may offer gen-
uine insight and may support patients in
therapy, too often they instead minimize
the impact of early abuse. They make it
easy to reproach the victims, to say, in so
many words, “Get over it.”
Research on the effects of early mal-
treatment, including the work of my
colleagues and myself at McLean Hospital
in Belmont, Massachusetts, appears to tell
a different story: that early maltreatment,
even exclusively psychological abuse, has
enduring negative effects on brain develop-
ment. We see specific kinds of brain abnor-
malities in psychiatric patients who were
abused as children. We are also beginning
to understand how these abnormalities may
account directly for the personality traits
and other symptoms that patients manifest.
With The Etiology of Hysteria (1896),
Sigmund Freud first introduced the topic
of childhood sexual abuse in a scientific
context. He was convinced that, as children,
many of his patients had been sexually
abused by their parents, older siblings, or
The Dana Forum on Brain Science
other relatives. Furthermore, he claimed,
based on his new analytical method, that
their hysterical and neurotic symptoms
could be traced directly to repressed memo-
ries of that early abuse. This hypothesis
marked the birth of psychoanalysis. Freud
later retreated from this theory, though,
refusing to believe that childhood abuse
could be as prevalent as he had initially
claimed. He evolved the more complex theory
that “memories” of early sexual abuse
were merely repressed childhood fantasies.
This theory has so swayed psychiatry for
almost a century that it has largely blinded
us to the frequency of real abuse in psychi-
atric patients’ childhoods and to the role of
abuse in psychopathology.
Physical abuse of children by their par-
ents remained a hidden problem until 1962,
when C. Henry Kempe published The Bat-
tered Child Syndrome, and an avalanche of
publicity led to the enactment of child abuse
reporting laws. During the 1970s, case
reports of sexual abuse and incest appeared
with increasing frequency in medical litera-
ture. By the 1980s, scientifically valid studies
of the incidence and consequences of child-
hood sexual abuse were being published.
Today, episodes of serious neglect
and physical abuse are featured regularly in
the news, constantly reminding us of the
horrifying cruelty adults inflict on children.
In separate surveys in San Francisco,
Los Angeles, and Canada, and of college
students in New England and Texas, the
percentage of women reporting sexual
abuse during childhood ranged from 19 to
45. The medical literature is replete with
research on this problem; clinicians, super-
sensitized to it, increasingly suggest that
childhood abuse lies behind a patient’s
problem, even in the absence of direct
evidence. Despite occasional hysteria and
misuse of the diagnosis, however, the
problem is all too real.
It is our hope that as we identify the
specific physiological pathways by which
abusive experiences alter brain develop-
ment, our society will take more seriously
the challenge of uprooting the violence
against the children in our midst.
A HARVEST OF PSYCHIATRIC DISORDERS
Physical, sexual, and psychological trauma
in childhood may lead to psychiatric diffi-
culties that show up in childhood, adoles-
cence, or adulthood. The victim’s anger,
shame, and despair can be directed inward
to spawn symptoms such as depression,
anxiety, suicidal ideation, and post-traumat-
ic stress, or directed outward as aggression,
impulsiveness, delinquency, hyperactivity,
and substance abuse.1
Childhood trauma may fuel a range
of persistent psychiatric disorders. One
is somatoform disorder (also known as
psychosomatic disorder), in which patients
experience physical complaints with no
discernible medical cause. Another is panic
Episodes of serious neglect and
physical abuse are featured
regularly in the news, constantly
reminding us of the horrifying
cruelty adults inflict on children.
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disorder with agoraphobia, in which
patients experience the sudden, acute onset
of terror and may narrow their range of
activities to avoid being outside, especially
in public, in case they have an attack.
More complex, difficult-to-treat
disorders strongly associated with child-
hood abuse are borderline personality
disorder2and dissociative identity disorder3
Someone with borderline personality disor-
der characteristically sees others in black-
and-white terms, first putting them on a
pedestal, then vilifying them after some
perceived slight or betrayal. Such people
have a history of intense but unstable rela-
tionships, feel empty or unsure of their
identity, often try to escape through sub-
stance abuse, and experience self-destructive
impulses and suicidal thoughts. They are
plagued by anger, most often directed at
themselves.
In dissociative identity disorder,
formerly called multiple personality disorder
(the phenomenon behind Robert Louis
Stevenson’s “Dr. Jekyll and Mr. Hyde”), at
least two seemingly separate people occupy
the same body at different times, each with
no knowledge of the other. This can be
seen as a more severe form of borderline
personality disorder. In borderline personal-
ity disorder, there is one dramatically
changeable personality with an intact mem-
ory, as opposed to several distinct personali-
ties, each with an incomplete memory.
People with dissociative identity disorder
have two or more (on average, eight to
fifteen) personalities or personality frag-
ments that control their behavior at
different times. Often there is a passive,
depressed primary identity who cannot
remember personal history as fully as can
the other more hostile, protective, or
controlling identities.
Post-traumat
ic stress disorder (PTSD)
afflicts some people who have undergone a
traumatic event involving serious injury or
a threat to life or limb. Initially identified in
combat veterans, PTSD seems to result as
well from natural disasters, child abuse, and
other devastating experiences. People with
PTSD keep re-experiencing the traumatic
event in waking life or in dreams, and they
actively avoid situations that might bring
back memories of the trauma. They may
also suffer a general numbing of their
responsiveness, show diminished interest in
significant activities, restrict the range of
their emotions, or have feelings of detach-
ment or estrangement from others. Finally,
they may also experience increased arousal
(such as difficulty falling or staying asleep),
irritability or outbursts of anger, difficulty
concentrating, hyper vigilance, and an
exaggerated startle response.
Initially identified in combat veterans,
PTSD seems to result as well from
natural disasters, child abuse, and
other devastating experiences.
People with PTSD keep re-experiencing
the traumatic event in waking
life or in dreams, and they actively
avoid situations that might bring
back memories of the trauma.
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ABUSE AND THE DEVELOPING
HUMAN BRAIN
For a century or more, scientists have
hotly contested the relative importance of
experience versus genetic endowment in the
development of the brain and behavior. We
know now that our genes provide the foun-
dation and overall structure of our brain,
but that its myriad connections are sculpted
and molded by experience. Based on
animal studies, scientists have long believed
that early deprivation or abuse may result
in neurobiological abnormalities, but until
recently there has been little evidence for
this in humans.
Then, in 1983, A. H. Green and his
colleagues suggested that many abused
children evidenced neurological damage,
even without an apparent or reported head
injury. Interestingly, although minor neuro-
logical disturbances and mild brain-wave
abnormalities were more common in
children who had been abused than in those
who had not, Green and his colleagues did
not believe that the abuse had caused them.
Instead, they saw these neurological distur-
bances as a possible additional source of
trauma, amplifying the damaging impact
of an abusive environment. In 1979, R. K.
Davies reported that in a sample of 22
patients involved as a child or as the
younger member in an incestuous relation-
ship, 77 percent had abnormal brain waves
and 36 percent had seizures. In Davies’s
interpretation, however, these children were
more vulnerable to being sexually abused
by family members because of their neuro-
logical handicap.
My hypothesis is that the trauma of
abuse induces a cascade of effects, including
changes in hormones and neurotransmitters
that mediate development of vulnerable
brain regions. Testing this hypothesis in
humans is difficult because abuse is not
always a random act. If we observe an asso-
ciation between a history of abuse and
the presence of a physical abnormality, the
abuse may have caused that abnormality.
But it is also possible that the abnormality
occurred first and elevated the likelihood
of abuse, or that the abnormality ran in the
family and led to more frequent abusive
behavior by family members or other relatives.
To try to sort out these competing
hypotheses, we conducted studies of analo-
gous early stress in animals, where the
potentially confusing elements can be care-
fully controlled. Observing parallel out-
comes in animals and people has bolstered
our belief that trauma causes brain damage,
not the other way around.
A CONSTELLATION OF ABNORMALITIES
Our research (and that of other scientists)
delineates a constellation of brain abnor-
malities associated with childhood abuse.
There are four major components:
Limbic irritability, manifested by
markedly increased prevalence of symptoms
Observing parallel outcomes in
animals and people has
bolstered our belief that trauma
causes brain damage, not the
other way around.
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suggestive of temporal lobe epilepsy (TLE)
and by an increased incidence of clinically
significant EEG (brain wave) abnormalities.
Deficient development and differentiation
of the left hemisphere, manifested throughout
the cerebral cortex and the hippocampus, which
is involved in memory retrieval.
Deficient left-right hemisphere integration,
indicated by marked shifts in hemispheric
activity during memory recall and by
underdevelopment of the middle portions
of the corpus callosum, the primary pathway
connecting the two hemispheres.
Abnormal activity in the cerebellar
vermis (the middle strip between the two
hemispheres of the brain), which appears to
play an important role in emotional and
attentional balance and regulates electrical
activity within the limbic system.
Let us look briefly at the main evidence
for each of these abnormalities.
Epilepsy-Like Symptoms
People with temporal lobe epilepsy (TLE)—
.25 percent to .5 percent of the U.S.
population—have seizures in the temporal
or limbic areas of the brain. Because these
areas constitute a sizable, varied part of the
brain, TLE has a veritable catalog of possible
symptoms, including sensory changes such
as headache, tingling, numbness, dizziness,
or vertigo; motor symptoms such as staring
or twitching; or autonomic symptoms
such as flushing, shortness of breath, nausea,
or the stomach sensation of being in an
elevator. TLE can cause hallucinations
or illusions in any sense modality. Common
visual illusions are of patterns, geometric
shapes, flashing lights, or “Alice-in-Wonder-
landlike” distortions of the sizes or shapes
of objects. Other common hallucinations
are of a ringing or buzzing sound or repeti-
tive voice, a metallic or foul taste, an
unpleasant odor, or the sensation of some-
thing crawling on or under the skin. Feelings
of déjà vu (the unfamiliar feels familiar)
or jamais vu (the familiar feels unfamiliar)
are common, as is the sense of being watched
or of mind-body dissociation—the feeling
that one is watching one’s own actions as a
detached observer. Emotional manifestations
of temporal lobe seizures usually occur
suddenly, without apparent cause, and cease
as abruptly as they began; they include
sadness, embarrassment, anger, explosive
laughter (usually without feeling happy),
serenity, and, quite often, fear.4
TLE is difficult to diagnose because
its symptoms can mimic those of other
psychiatric and nonpsychiatric illnesses. The
characteristic electrical discharge of TLE
can be observed only in an electroen-
cephalogram (EEG) during a seizure that is
close enough to the brain’s surface to be
picked up by scalp electrodes. Without this
Emotional manifestations of
temporal lobe seizures usually occur
suddenly, without apparent cause,
and cease as abruptly as they began;
they include sadness, embarrassment,
anger, explosive laughter (usually
without feeling happy), serenity,
and, quite often, fear.
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objective EEG data, a diagnosis must
be based on the frequency and severity of
symptoms and the ruling out of other likely
causes of those symptoms.
To explore the relationship between
early abuse and dysfunction of the tem-
porolimbic system, we devised the Limbic
System Checklist-33 (LSCL-33), which
calibrates the frequency with which patients
experience symptoms of temporolimbic
seizures.5We studied 253 adults who came
to an outpatient mental health clinic for psy-
chiatric assessment; slightly more than half
reported having been abused physically, sex-
ually, or both. Compared to patients who
reported no abuse, average LSCL-33 scores
were 38 percent greater in the patients with
physical (but not sexual) abuse, and were 49
percent greater in the patients with sexual
(but not other physical) abuse. Patients who
acknowledged both physical and sexual
abuse had average scores 113 percent greater
than patients reporting no abuse. Males and
females were similarly affected by abuse.
As we expected, abuse before age 18,
when the brain is still rapidly developing,
had a greater impact on limbic irritability
than later abuse. Patients physically or
sexually abused after age 18 had scores not
significantly different from nonabused
patients. Patients with both physical and
sexual abuse, however, were strongly affect-
ed regardless of when the abuse occurred,
and those first abused after age 18 were
almost as affected as those first abused earlier.
Brain Wave Abnormalities
Our second study tried to ascertain whether
childhood physical, sexual, or psychological
abuse was associated with specific evidence
of neurobiological abnormalities. We
reviewed the records of 115 consecutive
admissions to a child and adolescent psychi-
atric hospital to search for a link between
different categories of abuse and evidence
of abnormalities in brain-wave studies. We
found clinically significant brain-wave abnor-
malities in 54 percent of patients with a history
of early trauma but in only 27 percent of
nonabused patients. Among patients who
had been abused, abnormal EEG findings
were observed in 43 percent of those with
psychological abuse; 60 percent of the
sample with a reported history of physical
abuse, sexual abuse, or both; and 72 percent
of the sample in which serious physical
or sexual abuse had been documented. The
overall prevalence of abnormal EEG studies
in patients with a significant history of
abuse or neglect was the same for boys and
girls and for children and adolescents.
The salient specific difference between
abused and nonabused patients was in left-
sided EEG abnormalities. In the nonabused
group, left-sided EEG abnormalities were
rare, whereas in the abused group they
were much more common, and more than
twice as common as right-sided abnormali-
ties. In the psychologically abused group,
all the EEG abnormalities were left-sided.
To dig deeper into the possibility
that abuse may affect development of the
left hemisphere, we looked for evidence
of right-left hemispheric asymmetries in the
results of neuropsychological testing. We
compared patients’ visual-spatial ability
(predominantly controlled by the right
hemisphere) to their verbal performance
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(predominantly controlled by the left
hemisphere). In the nonabused group,
left-hemisphere deficits were about twice as
prevalent as right-hemisphere deficits,
but in patients with physical, sexual, or
psychogical abuse, left-sided deficits were
more than six times as prevalent as right.
In patients with a history of psychological
abuse, left-hemisphere deficits were eight
times as prevalent as right-sided deficits.
This corroborated our hypothesis that abuse
is associated with an increased prevalence
of left-sided EEG abnormalities and of
left-hemisphere defects in neuropsycho-
logical testing.
Problems on the Left
In order to investigate the effects of child-
hood trauma on development of the left
hemisphere, we then used a sophisticated
quantitative method of analyzing EEG that
provides evidence about the brain’s structure.7
In contrast to conventional EEG, which
reveals brain function, EEG coherence
provided information about the nature of
the brain’s wiring and circuitry. In general,
abnormally high levels of EEG coherence
are evidence of diminished development of
the elaborate neuronal interconnections in
the cortex that would process and modify
the brain’s electric signals.
We used this technique to study 15
child and adolescent psychiatric inpatients
who had a confirmed history of intense
physical or sexual abuse compared with 15
healthy volunteers. Patients and volunteers
were between 6 and 15 years of age, right-
handed, and with no history of neurological
disorders or abnormal intelligence. Measuring
EEG coherence indicated that the left
cortex of the healthy controls was more
developed than the right cortex, which is
consistent with what is known about the
anatomy of the dominant hemisphere.
The abused patients, however, were notably
more developed in the right than the left
cortex, even though all were right-handed.
The right hemisphere of abused patients had
developed as much as the right hemisphere
of the controls, but their left hemispheres
lagged substantially, as though arrested in
their development.
This abnormality in the cortex showed
up regardless of the patient’s primary diag-
nosis, which could be depression, PTSD, or
conduct disorder. It extended throughout
the entire left hemisphere, but the temporal
regions were most affected. This finding of
left cortex underdevelopment is consistent
with our earlier finding that abused patients
had increased left-hemisphere EEG abnor-
malities and left-hemisphere (verbal) deficits
as shown by neuropsychological testing.
Affects on the Hippocampus
The hippocampus, located in the temporal
lobe, is involved in memory and emotion.
Developing very gradually, the hippocampus
is one of the few parts of the brain that
continues to produce new cells after birth.
Cells in the hippocampus have an unusually
large number of receptors that respond to
the stress hormone cortisol. Since animal
studies show that exposure to high levels of
stress hormones like cortisol has toxic
effects on the developing hippocampus,
this brain region may be adversely affected
by severe stress in childhood.
The Dana Forum on Brain Science
negative emotions. We wondered, then,
whether abused children might store their
disturbing childhood memories in the
right hemisphere, and whether recollecting
these memories would activate the right
hemisphere more than it is activated in
those without such a history.
To test this hypothesis, we measured
hemispheric activity in adults during recall
of a neutral memory, then during recall
of an upsetting early memory.10 Those with
a history of abuse appeared to use predomi-
nantly their left hemispheres when thinking
about neutral memories and their right
when recalling an early disturbing memory.
Those in the control group had a more
integrated bilateral response.
A Deficient Pathway
Since childhood abuse (as we found) is
associated with diminished right-left hemi-
sphere integration, we wanted to know
whether there was some deficiency in the
primary pathway connecting the two hemi-
spheres, the corpus collosum. We found
in boys who had been abused or neglected
that the middle portions of the corpus
collosum were significantly smaller than in
the control groups. Furthermore, in boys,
neglect exerted a far greater effect than
any other type of maltreatment; physical
and sexual abuse exerted relatively minimal
effects. In girls, however, sexual abuse
was a more powerful factor, associated with
a major reduction in size of the middle por-
tions of the corpus collosum. These results
were independently replicated by Michael
De Bellis at the University of Pittsburgh,
and the effects of early experience on the
J. Douglas Bremner and his colleagues
at Yale Medical School compared magnetic
resonance imaging (MRI) scans of 17 adult
survivors of childhood physical or sexual
abuse, all of whom had PTSD, with 17
healthy subjects matched for age, sex, race,
handedness, years of education, body size,
and years of alcohol abuse.8The left hip-
pocampus of abused patients with PTSD was
12 percent smaller than the hippocampus of
the healthy controls, but the right hippocam-
pus was of normal size, as were other brain
regions, including the amygdala, caudate
nucleus, and temporal lobe. Not surprisingly,
given the role of the hippocampus in
memory, these patients also had lower verbal
memory scores than the nonabused group.
Murray Stein and his colleagues also
found left hippocampal abnormalities
in women who had been sexually abused as
children. Their left hippocampal volume
was significantly reduced, but the right hip-
pocampus was relatively unaffected. Fifteen
of the 21 sexually abused women had
PTSD; 15 had a dissociative disorder. They
suffered a reduction in the size of the left
hippocampus proportionate to the severity
of their symptoms.
These studies suggest that child abuse
may alter development of the left hippocampus
permanently and, in so doing, cause deficits
in verbal memory and dissociative symptoms
that persist into adulthood.
Shifting from Left to Right
The left hemisphere is specialized for per-
ceiving and expressing language, the right
hemisphere for processing spatial information
and also for processing and expressing
Testing this hypothesis, we found that
the vermis seems to become activated to
control— and quell—electrical irritability in
the limbic system. It appears less able to do
this in people who have been abused. If,
indeed, the vermis is important not only for
postural, attentional, and emotional balance,
but in compensating for and regulating
emotional instability, this latter capacity may
be impaired by early trauma. By contrast,
stimulation of the vermis through exercise,
rocking, and movement may exert additional
calming effects, helping to develop the vermis.
ATTENTION, HORMONES, AND THE BRAIN
We know that through their effects on
hormone levels, early experiences influence
brain development. Fifty years ago, Seymour
Levine and Victor Denenberg showed that
small alterations in their environment
led to lasting changes in rats’ development,
behavior, and response to stress. Something
as seemingly inconsequential as five minutes
of human handling during a rat’s infancy
produced lifelong beneficial changes. We
now understand through the reserach efforts
of Michael Meany and Paul Plotsky that the
effects of brief handling were highly beneficial
and were due to increased maternal attention.
Those pups whose mothers spontaneously
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development of the corpus collosum have
been confirmed by research in primates.
Calming Irritability in the Brain
Decades ago, Harry Harlow compared mon-
keys raised with their mothers to monkeys
raised with wire or terrycloth “surrogate
mothers.” Monkeys raised with the surro-
gates became socially deviant and highly
aggressive adults. Building on this work,
other scientists discovered that these conse-
quences were less severe if the surrogate
mother swung from side to side, a type of
movement that may be conveyed to the
cerebellum, particularly the part called the
cerebellar vermis, located at the back of the
brain, just above the brain stem. Like the
hippocampus, this part of the brain develops
gradually and continues to create new neu-
rons after birth. It also has an extraordinarily
high density of receptors for stress hormone,
so exposure to such hormones can markedly
affect its development.
New research suggests that abnormal-
ities in the cerebellar vermis may be
involved in psychiatric disorders including
depression, manic-depressive illness,
schizophrenia, autism, and attention-
deficit/ hyperactivity disorder. We have
gone from thinking of the entire cerebel-
lum as involved only in motor coordination
to believing that it plays an important role
in regulating attention and emotion. The
cerebellar vermis, in particular, seems to
be involved in the control of epilepsy or
limbic activation. Couldn’t maltreating
children produce abnormalities in the
cerebellar vermis that contribute to later
psychiatric symptoms?
Something as seemingly inconse-
quential as five minutes of
human handling during a rat’s
infancy produced lifelong
beneficial changes.
The Dana Forum on Brain Science
lick and groom them the most (about
one-third in a laboratory setting) display
the same benefits as the rats with the human
handling. By contrast, long isolation pro-
duces stress that has a deleterious effect on
brain and behavior development.
If we assume that lots of attention,
licking, and grooming are the natural state
of affairs and that lower levels of attention
are a form of neglect, we can use this mod-
el to explore some of the biological conse-
quences of neglect or abuse in children.
Low rates of maternal attention decrease
the production of thyroid hormone by the
rat pups. This, in turn, decreases serotonin
in the hippocampus and affects the devel-
opment of receptors for the stress hormone
glucocorticoid. Since corticosterone, one
of our primary stress hormones, is kept in
check by a complicated feedback mechanism
that depends on these same stress hormone
receptors, their inadequate development
increases the risk of an excessive stress hor-
mone response to adversity. For this and
certain other reasons, lack of maternal
attention predisposes the animals to have a
heightened level of fear and a heightened
adrenaline response. Some of the conse-
quences of this are altered metabolism and
suppressed immune and inflammatory
responses, neuronal irritability, and enhanced
susceptibility to seizures. Still other conse-
quences of an abnormally intense corticos-
terone response are reduced brain weight
and DNA content, suppressed cell growth
in the cerebellum and hippocampus,
and interference with myelinization—the
process of sheathing nerve fibers to
enhance conduction of electrical impulses.
These consequences seem consistent
with inadequate development of the corpus
collosum, which is a highly myelinated
structure, and abnormal development of
the hippocampus and cerebellum. High levels
of cortisol can also hinder development
of the cerebral cortex, the extent of vulner-
ability dependent on how rapidly the brain
was growing at the time of the insult. During
the years of rapid language acquisition
(approximately 2-10 years of age), the left
brain develops more rapidly than the right,
making it more vulnerable to the effects of
early maltreatment.
Finally, diminished maternal attention
also appears to be associated with a lifelong
decrease in production of the hormone oxy-
tocin in the brain, and enhanced production
of the stress hormone vasopressin. Recent
research by Thomas Insel suggests that
oxytocin is a critical factor in affiliative love
and maintaining monogamous relationships.
Both hormones may also help control
sexual response, with vasopressin enhancing
sexual arousal and oxytocin triggering
climax and release. By affecting these hor-
mones, early neglect or abuse theoretically
could predispose mammals to experience
enhanced sexual arousal, diminished capacity
for sexual fulfillment, and deficient commit-
ment to a single partner.
FROM NEUROBIOLOGY TO
SYMPTOMATOLOGY
In summary, we now know that childhood
abuse is linked with excess neuronal irri-
tability, EEG abnormalities, and symptoms
suggestive of temporal lobe epilepsy. It is
also associated with diminished development
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childhood abuse appears particularly likely
to be associated with emergence of ADHD-
like behavior problems. Interestingly, one
of the most reliable neuroanatomical findings
in ADHD is reduced size of the cerebellar
vermis. Some studies have also found an
association between reduced size of the mid
portions of the corpus callosum and emer-
gence of ADHD-like symptoms of impulsivity.
Hence, early abuse may produce brain
changes that mimic key aspects of ADHD.
Our discoveries that abused patients
have diminished right-left hemisphere inte-
gration and a smaller corpus callosum suggest
an intriguing model for the emergence of
one of psychiatry’s least understood afflictions:
borderline personality disorder. With
less well integrated hemispheres, borderline
patients may shift rapidly from a logical and
possibly overvaluing left-hemisphere state
to a highly negative, critical, and emotional
right hemisphere state. This seems consistent
with the theory that early problems of mother-
child interaction undercut the integration
of right and left hemispheric function. Very
inconsistent behavior of a parent (for exam-
ple, sometimes loving, sometimes abusing)
might generate an irreconcilable mental
image in a young child. Instead of reaching
an integrated view, the child would form two
diametrically opposite views—storing the
positive view in the left hemisphere, the neg-
ative view in the right. These mental images,
and their associated positive and negative
world views, may remain unintegrated, and
the hemispheres remain autonomous, as the
child grows up. This polarized hemispheric
dominance could cause a person to see
significant others as overly positive in one
of the left cortex and left hippocampus,
reduced size of the corpus callosum, and
attenuated activity in the cerebellar vermis.
We see a close fit between the effects of
early stress on the brain’s transmitters—our
discoveries about the negative effects of
early maltreatment on brain development—
and the array of psychiatric symptoms
that we actually observe in abused patients.
Many disorders are associated with
childhood abuse. One is depression or
heightened risk for developing it. Many
scientists believe that depression may be a
consequence of reduced activity of the
left frontal lobes. If so, the stunted devel-
opment of the left hemisphere related to
abuse could easily enhance the risk of devel-
oping depression. Similarly, excess electrical
irritability in the limbic system, and alter-
ations in development of receptors that
modulate anxiety, set the stage for the
emergence of panic disorder and increase
the risk of post-traumatic stress disorder.
Alterations in the neurochemistry of these
areas of the brain also heighten the hormonal
response to stress, producing a state of
hyper vigilance and right-hemisphere activa-
tion that colors our view with negativity
and suspicion. Alterations in the size of the
hippocampus, along with limbic abnormalities
shown on an EEG, further enhance the
risk for developing dissociative symptoms
and memory impairments.
We have also found that 30 percent of
children with a history of severe abuse meet
the diagnostic criteria for attention-
deficit/hyperactivity disorder (ADHD),
although they are less hyperactive than
children with classic ADHD. Very early
The Dana Forum on Brain Science
state and as resoundingly negative in
another. Couple this with possible alterations
in oxytocin- and vasopressin-mediated
sexual arousal, and you see why patients with
borderline personality disorder have tumul-
tuous relationships.
DEALING WITH THE DAMAGE
I hope that new understanding of childhood
abuse’s impact on the brain will lead to
new ideas for treatment. The most immediate
conclusion from our work, however, is
the crucial need for prevention. If childhood
maltreatment exerts enduring negative
effects on the developing brain, fundamentally
altering one’s mental capacity and personality,
it may be possible to compensate for these
abnormalities—to succeed in spite of them—
but it is doubtful that they can actually be
reversed in adulthood.
The costs to society are enormous.
Psychiatric patients who have suffered from
childhood abuse or neglect are far more
difficult and costly to treat than patients
with a healthy childhood. Furthermore,
childhood maltreatment can be an essential
ingredient in the makeup of violent
individuals, predisposing them to bouts of
irritable aggression.
One day we will find ways to chart
the progress of brain development so that
we can spot early signs of stress-mediated
abnormalities and monitor each patient’s
progress and response to treatment. In the
meantime, early intervention should be our
priority. The brain is more plastic and mal-
leable before puberty, increasing our chances
of minimizing or reversing consequences of
abuse. If we are right that many abuse-related
changes result from a cascade of stress-medi-
ated neuronal and hormonal responses,
then we could minimize the impact of abuse
by finding ways to reduce ongoing stress or
suppressing an excessive stress response.
One consequence of childhood mal-
treatment is limbic irritability, which tends to
produce dysphoria (chronic low-level unhap-
piness), aggression, and violence toward
oneself or others. Even into adulthood, drugs
can be useful in alleviating this set of symp-
toms. Anticonvulsant agents can help, as can
drugs that affect the serotonin system.
Abuse also causes alterations in left-
right hemisphere integration. Some research
suggests that anticonvulsant drugs may
facilitate the bilateral transmission of informa-
tion. Left-right hemisphere integration may
also improve through activities that require
considerable left-right hemisphere coopera-
tion, such as playing a musical instrument.
Certain existing psychotherapies may be
helpful. Cognitive-behavioral psychotherapy,
which emphasizes correcting illogical,
self-defeating perceptions, may work by
strengthening left-hemisphere control over
right-hemisphere emotions and impulses.
Traditional, dynamic psychotherapy may
work by enabling patients to integrate right-
hemisphere emotions while maintaining
left-hemisphere awareness, strengthening
the connection between the two hemispheres.
A powerful new tool for treating PTSD
is eye-movement desensitization and repro-
cessing (EMDR), which seems to quell
flashbacks and intrusive memories. A moving
visual stimulus is used to produce side-to-side
eye movements while a clinician guides
the patient through recalling highly disturbing
Cerebrum
At the extreme, the coupling of severe
childhood abuse with other neuropsychiatric
handicaps (for example, low intelligence,
head trauma, or psychosis) is repeatedly
found in cases of explosive violence. Dorothy
Otnow Lewis and Jonathan Pincus have
analyzed the neurological and psychiatric
history of violent adolescents and adults.
In one study they evaluated all 14 juveniles
condemned to death in four states and
found that all had suffered head injuries,
most had major neurological impairment,
12 had subnormal IQ’s, 12 had been
severely physically abused as children, and 5
had been sodomized by relatives. In another
study, they reviewed the childhood neuropsy-
chiatric records and family histories of
incarcerated delinquents. What might have
been a tip-off to those who later were
arrested for murder? The future murderers
were distinguished from other delinquents
by psychotic symptoms, major neurological
impairment, a psychotic first-degree relative,
violent acts during childhood, and severe
physical abuse.
In a follow-up study of 95 formerly
incarcerated juvenile delinquents, they
found that the combination of intrinsic
neuropsychiatric vulnerabilities and a history
of childhood abuse or family violence effec-
tively predicted which adolescents would
go on to commit violent crimes. Lewis con-
cludes that child abuse can engender all
pivotal factors associated with violent
behavior, namely, impulsivity, irritability,
hyper vigilance, paranoia (which she interprets
as an extreme version of hypervigilance),
decreased judgment and verbal ability, and
diminished recognition of pain in oneself
memories. For reasons we do not yet fully
understand, patients seem able to tolerate
recall during these eye movements and can
more effectively integrate and process their
disturbing memories. We suspect that this
technique works by fostering hemispheric
integration and activating the cerebellar vermis
(which also coordinates eye movements),
which in turn soothes the patient’s intense
limbic response to the memories.
THEIR CHOICE—OR OURS?
Society reaps what it sows in nurturing its
children. Whether abuse of a child is physical,
psychological, or sexual, it sets off a ripple of
hormonal changes that wire the child’s brain
to cope with a malevolent world. It predisposes
the child to have a biological basis for fear,
though he may act and pretend otherwise.
Early abuse molds the brain to be more irrita-
ble, impulsive, suspicious, and prone to be
swamped by fight-or-flight reactions that the
rational mind may be unable to control. The
brain is programmed to a state of defensive
adaptation, enhancing survival in a world of
constant danger, but at a terrible price. To a
brain so tuned, Eden itself would seem to hold
its share of dangers; building a secure, stable
relationship may later require virtually super-
human personal growth and transformation.
Whether abuse of a child is
physical, psychological, or sexual,
it sets off a ripple of hormonal
changes that wire the child’s brain
to cope with a malevolent world.
The Dana Forum on Brain Science
(dissociation) and others. As our review
shows, these factors fit closely with the
enduring neurobiological consequences
of abuse.
To be convicted of a crime in the
United States, one supposedly must have
the capacity both to know right from
wrong and to control one’s behavior. Those
with a history of childhood abuse may
know right from wrong, but their brains
may be so irritable and the connections
from the logical, rational hemisphere so
weak that intense negative (right-hemisphere)
emotions may incapacitate their use of
logic and reason to control their aggressive
impulses. Is it just to hold people criminally
responsible for actions that they lack the
neurological capacity to control?
Prosecutors and pundits are quick to
coin catchphrases like the “abuse excuse” to
dismiss childhood trauma’s pervasive and
enduring consequences for behavior. This is
as unthinking as the exhortation to “get
over it.” Childhood trauma is not a passing
psychological slight that one can choose
to ignore. Even if the abused person comes
to terms with the traumatic memories and
chooses (for the sake of sanity) to forgive
the perpetrator, this will not reverse the
neurobiological abnormalities. The only
sound legal approach to a person with a
history of abuse who commits a violent
crime is to take into account the person’s
neurobiological capacity to control his
behavior. If it is irrational and hypocritical
to hold a minor to the same standard of
behavioral control as a mature adult, it is
equally unjust to hold a traumatized and
neurologically impaired adult to the same
standard as one not so afflicted. Childhood
abuse, age, and neurological impairments
can be critical mitigating factors that a just
society should not ignore.
If we know that the roots of violence
are fertilized by childhood abuse, can we
make a long-term commitment to reduce
violence by focusing on our children rather
than our criminals? What if we set a goal of
reducing the cases of childhood abuse and
neglect by 50 percent a year? What if we
monitored statistics on childhood abuse as
avidly as we track housing starts, inflation,
or baseball scores? We would have to commit
ourselves, seriously, to improving access to
quality day care and after-school programs.
We might need to educate and support
parents so they could know how to nurture
their children more effectively. We certainly
would need to foster better relationships
among peers and siblings.
Think of what we could save if we
needed fewer prisons and fewer mental
health professionals. Think of the benefits
of moving one step closer to a society
that everyone could experience and enjoy.
Our brains are sculpted by our
early experiences. Maltreatment is a chisel
that shapes a brain to contend with
If we know that the roots of
violence are fertilized by childhood
abuse, can we make a long-term
commitment to reduce violence by
focusing on our children rather
than our criminals?
Cerebrum
strife, but at the cost of deep, enduring
wounds. Childhood abuse isn’t something
you “get over.” It is an evil that we must
acknowledge and confront if we aim to
do anything about the unchecked cycle of
violence in this country.
Author’s note: Rebecca Feldman and
Sydney Sauber assisted in writing this article.
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