The importance of mood disorders:
The concept of a diagnostic hierarchy in psychiatry
Mood disorders are central to any diagnostic evaluation in
psychiatry;this is so because of the concept of a diagnostic
hierarchy. Derived from the European tradition in psychiatry,
this approach argues that certain diagnoses should not be
made (those lower on the hierarchy)if other diagnoses are
present(those higher on the hierarchy).In this perspective,
mood disorders sit at the top of the diagnostic hierarchy
(Table 1.1). Thus,if a patient has a psychotic symptom, such
as hearing voices,then a psychotic disorder such as schizophrenia
should not be diagnosed unless mood disorders are
first ruled out(e.g.,the patient is not hearing voices owing to
psychotic unipolar depression). Similarly,if a patient appears
to have borderline personality disorder,this condition should
not be diagnosed unless either mood disorders are shown to
be absent or, alternatively,the patient with a mood disorder is
currently euthymic (not in an active mood episode). The same
issue holds with attention deficit hyperactivity disorder
(ADHD).It should not be diagnosed in the presence of an
active mood disorder.
In other words, mood disorders can produce,in addition to
their own mood symptoms, almost any other psychiatric
symptom;thus mood disorders are the conditions that are
most likely to be missed when other symptoms are present.
The assessment of a possible diagnosis of mood disorders is
important,therefore, not only in persons with mood symptoms
but also in persons with any psychiatric symptoms of
any kind.
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TABLE 1.1. The Diagnostic Hierarchy of Psychiatric Disorders
I. Mood disorders
II. Psychotic disorders
III. Anxiety disorders
IV. Personality disorders
V. Other disorders (e.g., ADHD, eating disorders, conversion
disorders, dissociative disorders, sexual disorders)
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Historical background
Perhaps the simplest approach to understanding mood disorders
is to see them essentially as variations of depression. In
some ways, depression is easily understood. Most people can
relate to the sorrow of a sad mood, and it only takes some
experience and evidence to explain the extra features that are
required to diagnose a clinical syndrome. Mood disorders are
depressive syndromes that come in various flavors. The two
main types of depression are unipolar and bipolar disorders.
In unipolar depression, euthymia (i.e., normal mood)is the
only mood state (other than depression) experienced by the
individual. In bipolar depression, mood states that are better
than euthymia (i.e., euphoric, expansive with associated features)
also can occur.
This is the simplest breakdown of mood disorders. Some
might argue, however,that we should not even make this distinction.
In fact,100 years ago,the mainstream view upheld
by Emil Kraepelin was that mood disorders were a single
entity with variations on a spectrum. Kraepelin called the
overall condition manic-depressive illness, and within this
concept, he included both those who experienced only
depressive episodes (unipolar disorder) and those who also
experienced manic symptoms (bipolar disorder). The current
terminology of bipolar versus unipolar conditions did not
come into common use until the 1960s and was not codified
in mainstream jargon until 1980 (with DSM-III).
What led to the acceptance of this distinction? The first
step was the vague relabeling of Kraepelin's manic-depressive
illness to affective disorders, a term coined by Swiss psychiatrist
Eugene Bleuler. The next step was the application of validating
criteria to affective disorders to see if any subtypes
would stand out.
Validating criteria are an important conception of psychiatry.
More consistently than other medical specialties, psychiatry
possesses no "gold standard"—no blood test, x-ray, or laboratory
value—to definitively establish the "reality" of a given
diagnosis. In the absence of a "gold standard," researchers have
devised overtime a series of validators that,taken together, can
approximate something approaching certainty in the validity of
a diagnosis. Four standard validating criteria that were implemented
in the 1960s are listed in Table 1.2.
Decades ago, with little evidence from treatment response,
researchers focused on the course of the illness and family
history as independent validators for a diagnosis (beyond traditional
signs and symptoms). This research led to the bipolar/unipolar
distinction when evidence was found that these
two groups of patients could be separated on the basis of
those diagnostic validators. Individuals with bipolar disorder
tended to have family histories of the same illness or unipolar
depression, but individuals with unipolar depression did
not tend to have family histories of bipolar disorder. Further,
bipolar disorder was recurrent in almost all patients invariably,
whereas unipolar depression did not recur (consisted of
only one or two episodes)in about half of patients.
Thus the separation of mood disorders into unipolar and
bipolar is based on this empirical research. As such,it is liable
to alteration based on further empirical research. Some believe
that Kraepelin's original broad view of manic-depressive illness
still has merit, as I will discuss later.
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TABLE 1.2. Criteria for the Validation of a Psychiatric Diagnosis
1. Symptoms
2. Course of illness (age of onset, natural history)
3. Treatment response
4. Family history
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Differentiating Bipolar and Unipolar depression
In contemporary psychiatry,then, mood disorders are either
unipolar or bipolar. The distinction involves whether or not
manic/hypomanic episodes are present. Depression is rarely
absent and is usually common to both conditions.
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CLINICAL VIGNETTE:Unipolar
The patient was somewhat sad as a child but was never diagnosed
or treated for depression until age 30. soon after the
ending of her marriage. She became depressed in mood,
uninterested in most activities, gained 20 pounds, was tired
most of the time, and sometimes thought life was not worth
living, although she never seriously considered harming herself.
On careful questioning of her and her mother, no evidence
of a single manic or hypomanic episode in the past was
found. She responded to sertraline quickly and was tapered
off th
e medication after 1 year. She then did well for 3 years
e medication after 1 year. She then did well for 3 years
but became depressed again after being laid off, with recovery
after resumption of sertraline. She eventually stopped the
medication after 2 years and experienced another depression
at age 42. with no apparent stressor occurring in her life. The
diagnosis is recurrent unipolar depression.
—————————————————————–
—————————————————————–
CLINICAL VIGNETTE:BPⅡ
The patient is a 34-year-old white man who has been severely
depressed for the past year with daily depressed mood;
decreased energy,interest, and appetite; and intermittent suicidal
ideation. He seeks his first psychiatric evaluation voluntarily.
(At this point, all we know is that he has current
major depression. We do not know if it is unipolar or bipolar.)
On questioning, he denies any known family history of
psychiatric illness. He also denies any periods of hyperactivity
leading to problems in his life (mania), but, on further
questioning,reports that he has experienced times where he
felt better than average in his mood,lasting 3 to 4 days at the
longest, associated with increased energy, decreased sleep,
increased talkativeness, and increased activities at school and
at work.(This description meets the definition of hypomania.)
The last such period occurred 2 years ago. The interviewer
diagnoses bipolar depression type II.
——————————————————————
——————————————————————
CLINICAL VIGNETTE:BPⅠ
The patient was diagnosed and treated for depression at age 19
after becoming markedly depressed on arriving at college. He
recovered soon after treatment with fluoxetine, and the medication
was discontinued 6 months later. One year afterwards,
he experienced another period of depression that lasted 4 weeks
and resolved on its own, with an apparent stressor of a breakup
with his girlfriend. While he denied this, his girlfriend reports
that he then experienced 1 month of increased energy,
decreased sleep,irritable mood,increased activities, and
increasing conflict between him and his friends. His schoolwork
suffered during that month because he felt more capable
of passing his courses without studying. He was unusually talkative
during that period also. He then became markedly
depressed again for 2 months, and this responded to lithium
alone. The diagnosis is bipolar disorder type I.
——————————————————————
It is a common misconception to speak of depression and
bipolar disorder as if they represent two separate groups of
patients. This is a mistake. By bipolar disorder, people seem to
imply mania, and thus the contrast with depression. However,
I think a more useful way of thinking about this distinction
is to view all mood disorders as depression; with bipolar and
unipolar variations. In this way, when someone has depression,
we will not forget to assess them for bipolarity
A larger issue is at play here. It is important to emphasize to
clinicians and to patients that depression is not a diagnosis.
Depression is meaningless, diagnostically speaking. To say that
someone has depression merely means that he or she has a
number of signs and symptoms of the depressive syndrome.
This does not give you a diagnosis. Rather, we should recognize
this as being similar to an internist saying that someone has a
fever and chills. This collection of symptoms is not a diagnosis.
The internist needs to work up the illness to determine What
kind of diagnosis is producing the fever and chills. Similarly,in
mood disorders,it is a tautology to say that someone has
depression. Once we know that someone has depressive
symptoms,the diagnostic process involves identifying the illness
that is producing it.
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TIP
Any depressed patient is not diagnosable until past mania or
hypomania is ruled out. To say that someone has depression
is diagnostically meaningless. Depression is not a diagnosis;it
is merely a collection of symptoms. It is like saying that someone
has a fever. The relevant diagnoses are unipolar or bipolar
depression, with attendant differences in treatment.
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In this process,there are three steps (Fig.1.1). First,the clinician
needs to determine if the depressive syndrome is primary
or secondary. If it is secondary,there is an unequivocal cause
(most commonly substance abuse),followed by medical illness
(such as hypothyroidism).If an etiology cannot be established
definitively, which is usually the case,then primary depression
is diagnosed.
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(Fig.1.1)The differential diagnosis of depression.
ーーBipolar
ーーーPrimary ・・・
Etiology not definitive |
| ーーUnipolar(1) ーー Recurrent
Etiology not definitive |
| ーーUnipolar(1) ーー Recurrent
| ーー Nonrecurrent
Depression |
ーーーSecondary・・・Etiology definitive*|ーーMedical |ーーPsychosocial
|ーーOther**
*A definitive etiology means almost absolute evidence of
causation; otherwise, probable or possible relationships represent
triggers and not clear etiologies (e.g., necessary and sufficient
by itself to produce the outcome).
**For example, substance abuse.
(1)Primary unipolar depression is a diagnosis of exclusion once
all other possible depressive syndromes have been ruled out.
単極性で反復しないという場合と
二次性で心理社会的に発生したものと
現在症での区別は難しいと思う
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KEY POINT
It is important to emphasize that various factors, medical
and psychosocial, are often associated with primary depression,
but unless they are definitively etiologic by themselves,
secondary depression is not diagnosed.
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Once primary depression is diagnosed,the clinician then
needs to determine if it is of the unipolar or bipolar subtypes
based on whether or not the patient has experienced a past
episode of mania or hypomania.
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KEY POINT
Only one single spontaneous manic or hypomanic episode ever
is required to diagnose bipolar rather than unipolar depression,
An individual could have many depressive episodes, but the
onus is on the clinician to rule out a single manic/hypomanic
episode before diagnosing unipolar depression.
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Unfortunately,it appears to be common practice for
patients to go to clinicians who identify depression and then
diagnose "depression." Since "depression" is identified with
unipolar depression,in this approach, secondary and bipolar
depression will tend to be underdiagnosed.
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TABLE 1.3. Subtypes of Depressive Syndromes
Typical
Atypical
Psychotic
Melancholic
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1. Typical depression is characterized by decreased sleep and
energy and a diurnal variation in mood in which depression
worsens as the day progresses.
2. Atypical depression is characterized by increased sleep
and energy, a personality style of rejection sensitivity, and
preserved reactivity of mood (the ability to feel better
briefly). This type of depression is less responsive to
tricyclic antidepressants (TCAs)than to monoamine oxidase
inhibitors (MAOIs) or possibly serotonin reuptake
inhibitors (SRIs). Atypical depression is somewhat more
frequent in bipolar than unipolar types of depression.
3. Psychotic depression is characterized by the presence of
delusions or hallucinations along with standard depression
criteria. Such patients also tend to have severe psychomotor
retardation or agitation and marked guilt. Psychotic depression
responds better to atypical than typical antipsychotic
agents and usually requires combination treatment with
antipsychotics and antidepressants. It can be misdiagnosed
as schizophrenia (where the depressive component is
missed) or depression (where the psychotic component is
missed).It also is more common in bipolar than in unipolar
depression.
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Tip
A young person (<25 years of age) with psychotic depression
also has a significant likelihood of having bipolar disorder
(will later manifest mania).
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4. Melancholic depression is characterized by typical depressive
features but with marked anhedonia (i.e.,lack of interest
in all activities), no reactivity of mood (i.e.,inability to
feel better even briefly), and reversed diurnal variation in
mood (i.e.,feeling more depressed in the morning and better
as the day progresses). Melancholia is usually conceptualized
as a rather severe version of typical depression. This
subtype responds better to TCAs than to SRIs, and often
requires hospitalization.
1． Dysthymia is defined as mild depressive symptoms (at
least two DSM-IV neurovegetative criteria but not more
than four) occurring more often than not (meaning more
than 50% of the time)for a period of at least 2 years in
adulthood or 1 year in adolescence without any period of
stable euthymia lasting 1 month or longer. This definition
is actually quite strict, and an important clinical mistake
to avoid is to simply call someone dysthymic who has current
mild depressive symptoms or who has mild depressive
symptoms between major depressive episodes. Pure
dysthymia requires the absence of any major depressive
episode ever. This is quite uncommon. More frequently,
dysthymia occurs along with recurrent major depression
(double depression).
2． Major depressive disorder is the DSM-IV term for what I
will call unipolar depression throughout this book. It consists
of major depression in the absence of mania or hypomania
and has three varieties: single episode (which
occurs in about 50%),recurrent(the other 50%), and
chronic (based on whether the episode lasts 1 year or
longer).It is important to distinguish chronic unipolar
depression from dysthymia.In chronic depression, criteria
for major depression are met(five or more neurovegetative
symptoms);in dysthymia,they are not. A common
mistake is to call a depressive condition dysthymia
because it is long lasting.
1. In bipolar disorder type I, at least one manic episode is
identified, with or without major depression.
2. In bipolar disorder type II, not a single manic episode is
identified, at least one hypomanic episode is identified,
and at least one major depressive episode is identified.
3. In cyclothymia, major depressive symptoms do not reach
the threshold for d
iagnosis of a major depressive episode,
iagnosis of a major depressive episode,
and mood elevation symptoms, while present, do not
reach the threshold for diagnosis of a manic episode.
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TABLE 1.5. Subtypes of Bipolar Disorder
Bipolar disorder type I: Mania, with or without depression
Bipolar disorder type II: Hypomania, with major depression
Cyclothymia: Hypomanic symptoms plus subthreshold depressive symptoms for 2 years
Pure mania: Euphoric or irritable mood
Mixed mania: Depressed mood
Rapid cycling: Four or more mood (of any polarity) episodes in a year
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Tip
The key difference between mania and hypomania is that
mania is associated with significant social or occupational dys-
function (e.g., spending sprees, sexual indiscretions,reckless
driving, and impulsive traveling), whereas hypomania is not.
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Bipolar disorder not otherwise specified (NOS)is a controversial
but potentially important diagnosis because it helps to
define patients on the bipolar spectrum who are atypical;that
is,they do not meet classic criteria for bipolar disorder types
I or II, but they also do not meet classic criteria for major
depressive disorder or dysthymia. These are generally individuals
with major depressive episodes who have some features
of bipolarity (e.g.,family history of bipolar disorder,
hypomanic symptoms that last fewer than 4 days,
antidepressant-induced mania or hypomania, and so on).I have listed
features of bipolarity in Table 1.6 and will discuss them further in Chapter 3.
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TABLE 1.6. Features of Bipolarity
-Characteristics of depressive episodes
-Brief(<3 months' duration)
-Recurrent(>5 episodes)
-Atypical(especially in age <25)
-Psychotic (especially in age <25)
-Treatment resistant(failed three or more antidepressants)
-Antidepressant-induced mania or hypomania
-Family history of bipolar disorder type I(possibly substance abuse and SZ)
-Hyperthymic personality (between episodes)
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Rapid-cycling bipolar disorder identifies a course of
numerous mood episodes, defined as four or more episodes
in a year.Itis a course criterion, not a subtype of bipolar
disorder.
Diagnosing major depression
In order to diagnose a major depressive episode, an individual
must have depressed mood ("sad, down, blue") most of
the day, nearly every day,for at least 2 weeks continuously,
along with four of the eight depressive neurovegetative
symptoms. Or an individual may have anhedonia (i.e., complete
loss of interest in all or almost all of one's activities)
most ofthe day, nearly every day,for atleast 2 weeks continuously,
along with four of the other seven depressive neurovegetative
symptoms. Thus one can have a major depressive
episode without having depressed mood per se.
The neurovegetative symptoms of depression can be
remembered easily with the mnemonic derived from staff at
Massachusetts General Hospital: SIG E CAPS, meaning prescribing
energy capsules (Fig.1.2).
S: Sleep. Sleep is either decreased or increased, nearly every
day.
I:Interest. Loss of interest in all or almost all of one's activities,
nearly every day, or being unable to enjoy what one used to
enjoy, nearly every day.
G; Guilt. Feeling excessively guilty about things one has done or
not done, orfeelings of worthlessness (not simply loss of self
esteem), nearly every day.
E; Energy. Marked loss of energy, nearly every day.
C. Concentration. Decreased, concentration. This differs from the
distractibility of mania (see Note below).
A: Appetite. Appetite is either decreased or increased, nearly
every day.
P: Psychomotor changes. Psychomotor retardation represents
moving or thinking more slowly than usual, and psychomotor
agitation represents physical restlessness.
S: Suicide. Suicidal ideation may be present.
Allthese criteria contain a severity aspect(i.e., marked,
significant, or appreciable)thatreflects the conceptthatthey
are not brief ortransient;they should occur most ofthe time
most days in the 2-week orlonger period (with the exception
of suicidality, which, even when brief,is counted as a depressive
criterion).
**************************************************************
Tip
Any amount of suicidality is abnormal, should never be
ignored, and should elicit a careful search for other depressive symptoms.
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Mania
What is mood elevation? It is irritable or euphoric mood,
with the right number of the cardinal symptoms of mania.
Note:It is not just euphoric mood. While many persons with
mania report "high" or "happy" mood, many have only irritable
mood. Sometimes clinicians make the mistake of
identifying mania with euphoria, whereas one can have mania
without any euphoric mood at all. Manic episodes can be
classically euphoric, or they can be characterized by only irritable
mood. Either type is still described as pure mania.
Depressed mood can also co-occur with manic symptoms,
which, with other depressive neurovegetative symptoms, can
meet the criteria for a mixed episode. Mixed manic episodes
are as common as pure manic episodes.
To be diagnosed with a manic episode, an individual must
experience irritable or euphoric mood with three (if euphoric)
or four( if irritable) of the seven cardinal symptoms of mania
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FIG.1.3. DIGFAST mnemonic for mania.
FOI = flight ofideas; mania = euphoric mood + three criteria
orirritable mood + four criteria for1 week (or hospitalized) +
significant social /occupational dysfunction.
******************************************************
for1 week. The cardinal symptoms of mania are easily remembered
by another Massachusetts General Hospital mnemonic:
DIGFAST,reminding one of the excessive activity of mania
(Fig.1.3).
D: Distractibility. This is the most common manic symptom but
also the most subjective. It represents being unable to maintain
one's focus on tasks for an extended duration of time. It differs
from the decreased concentration of depression, as described in
the note below.
I:Insomnia. By this I mean decreased need for sleep, unlike
depressive insomnia, w
hich is simply decreased sleep. The best
hich is simply decreased sleep. The best
way to differentiate the two is to ask about the patient's energy
level.In manic insomnia, despite decreased sleep,the energy
level is average or high.In depressive insomnia,it is low.
G: Grandiosity.
F: Flight of ideas. Racing thoughts represent rapid progression in
one's thought process.
A: Activities. This represents increased goal-directed activities,
which are functional and often appear useful;they fall into
four categories:(1) social—increased socializing, calling
friends,going out more than usual;(2) sexual—increased libido or
hypersexuality;(3) work—increased productivity, cleaning the
house more than usual; and (4) school—producing many projects,
studying more than usual.In all cases, usual levels of
activity need to be based on a comparison with activity levels
during the euthymic state.
S: Speech. Pressured speech or increased talkativeness. Pressured
speech may be present in the mental status examination. If
not,rate increased talkativeness, or ask the patient to report
his or her level of talkativeness in the time period being
assessed compared with euthymia.
T: Thoughtlessness. Pleasure-seeking activities that do not display
usual judgment and thus, unlike increased goal-directed
activities, are dysfunctional. There are four common varieties:
(1) sexual indiscretions,(2)reckless driving,(3) spending
sprees, and (4) sudden traveling.
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Tip
The most reliable and useful manic criterion is decreased need
for sleep.Identify such a period first during the interview, and
then assess other manic synptoms carefully in that time
frame.
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As noted previously,for a diagnosis of a manic episode,in
addition to the preceding criteria,there also must be significant
social or occupational dysfunction arising from the preceding
symptoms. If there is no social or occupational dysfunction,
then the diagnosis is a hypomanic episode. Also,for a diagnosis
of a manic episode,the symptoms must last at least 1 week
(or lead to hospitalization).If they last less than 1 week but at
least 4 days,then the diagnosis is a hypomanic episode.
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KEY POINT
To diagnose hypomania, you mustrule out any significant social
or occupational dysfunction. Otherwise,the diagnosis is mania.
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Tip
By definition, hospitalization implies significant dysfunction.
Therefore,there is no such thing as a hypomanic hospitalized
patient.
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You do not need to have classic manic symptoms of dysfunction,
such as sexual indiscretions or spending sprees,to be
diagnosed with mania; any kind of significant social or occupational
dysfunction is sufficient.
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