Pediatric Bipolar Disorder
Science Update
February 8, 2006
Largest Study to Date on Pediatric Bipolar Disorder Describes
Disease Characteristics And Short-Term Outcomes
Recent findings from the multi-site, NIMH-funded Course and Outcome
of Bipolar Illness in Youth (COBY) study are helping to shape the
understanding of three major subtypes of bipolar disorder that
affect children and adolescents and how this diagnosis may affect
them as adults. Also known as manic-depressive illness because of
its recurring episodes of mania and depression,
bipolar disorder is a serious, chronic illness which causes
shifts in a person's mood, energy, and ability to function. Before
the COBY study, there had been few studies on the symptom patterns
and course of the disorder in the pediatric population.
Understanding the effects of bipolar disorder early in life may lead
to better treatments and improve long-term outcomes as these
children and adolescents become adults.
Overall, bipolar disorder appears to affect children and adolescents
more severely than adults. Study participants had comparatively
longer symptomatic stages and more frequent cycling (changing from
one mood to another) or mixed episodes. Children and adolescents
also converted from a less severe form of bipolar disorder to a more
severe form at a much higher rate than seen in adults.
This study comprises the largest pediatric bipolar population to
date, following the course and outcome of 263 children and
adolescents, ages 7-17 years. These findings were published in the
February 2006 issue of the
Archives of General Psychiatry. Future reports will
cover in more detail the characteristics of bipolar spectrum
disorders in children and adolescents, the longer-term disease
progression, predictive factors of disease outcome, such as
co-occurring disorders or family psychiatric history, and the
effects of different types of treatments.
Subtypes of Bipolar Disorder
The
three major subtypes of bipolar disorder (BP) included in this study
were BP-I, BP-II, and Bipolar Disorder Not Otherwise Specified (BP-NOS),
the most commonly seen subtype in pediatric psychiatric clinics. In
accordance to guidelines set by the Diagnostic and Statistical
Manual-IV (DSM-IV), BP-I was determined by primarily manic
(abnormally "high" and/or irritated) episodes and BP-II was
determined by an alternating pattern between depressive and
hypomanic (a less severe form of mania) episodes. BP-NOS is not
clearly defined in the DSM-IV, so the researchers determined this
type by "the presence of elated mood, plus two associated DSM-IV
symptoms, or irritable mood plus three DSM-IV associated symptoms,
along with a change in the level of functioning;" the symptoms had
to have lasted at least 4 hours within a 24-hour period for at least
4 "cumulative lifetime days."
Of
the total study population who had at least one follow-up assessment
over an average time of 1.5 years, 57 percent had BP-I, 8 percent
had BP-II, and 35 percent had BP-NOS. Researchers tracked changes in
symptoms and instances of recovery or recurrence. Recovery was
defined as having 8 consecutive weeks with minimal or no symptoms.
Recurrence, or having a new episode, was defined as meeting the full
DSM-IV criteria for a particular diagnosis with different degrees of
severity or impairment for one week in the case of mania or
hypomania (a less severe form of mania), or two weeks in the case of
depression.
Symptom Course,
Recovery, and Recurrence
Approximately 70 percent of all the study participants recovered
from their index episode (the episode that brought them to the
study's attention) and 50 percent had at least one recurrence. Those
with BP-I recovered and recurred more frequently than those with BP-NOS,
who took the longest time to reach recovery or recurrence. On
average, during the follow-up period, the participants spent 39.2
percent of the time symptom-free, 22.6 percent meeting the criteria
for a DSM-IV episode, and 38.2 percent with some symptoms but not
meeting DSM-IV criteria. However, even during the symptom-free
periods, many participants had ongoing co-occurring psychiatric
disorders (such as attention deficit hyperactivity disorder, or
ADHD). In addition, 12 percent experienced at least one week of
psychotic symptoms (such as hallucinations or delusions) and 15
percent made at least one suicide attempt or gesture. There were no
completed suicides in the COBY study.
Over the follow-up period, 20 percent of those with BP-II converted
to BP-I; of those with BP-NOS, 18.5 percent converted to BP-I and
6.5 percent converted to BP-II.
Predictors of
Outcome
Younger age of onset, low socio-economic status, and psychotic
symptoms were common factors in study participants who had worse
outcomes. In comparison with studies of bipolar disorder in adults,
the researchers found major differences in the course of illness in
children, which may have a serious impact on their emotional,
cognitive, and social development.
Compared to adults with BP-I, COBY participants with BP-I spent
significantly more time in a symptomatic stage and had more mixed
and cycling (changing from one mood to another) episodes, mood
symptom changes, and polarity switches. Also, the rate of conversion
between BP-II and BP-I found in COBY is higher than the rate of
conversion commonly reported in studies on adults. Furthermore, this
is the first study to suggest the relative instability of the BP-NOS
subtype, due to the number of participants who converted to BP-I or
II.
For
more information on bipolar disorder in children and adolescents,
visit:
·
http://www.nimh.nih.gov/publicat/bipolar.cfm
·
http://www.nimh.nih.gov/publicat/bipolarupdate.cfm
·
http://www.nimh.nih.gov/publicat/bipolarresfact.cfm
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