Premenstrual Syndromes : PMS and PMDD - Rutuja :: The site ...

50 THE PREMENSTRUAL SYNDROMES
on the other hand. Finally, there are no unique blood
tests or other markers for PMS, PMDD, or indeed any
mood or anxiety disorders. Emotional symptoms of low
mood, disinterest, irritability, and anxiety occur as part
of many mood and anxiety disorders, as well as PMS
and PMDD, and are not unique to any of the various
conditions. The feature that most highly differentiates a
premenstrual condition from other mood or anxiety
disorders is the temporal linkage of symptom expression
to the premenstrual phase of the menstrual cycle,
rather than patient characteristics or signs and symptoms.
Given these limitations, we organize this chapter
by comorbid condition and provide prevalence estimates
for premenstrual worsening of other psychiatric illnesses
as well as lifetime comorbidity. Further, we indicate
whether data on comorbidity rely on retrospective
assessments of a premenstrual condition or were made
after completion of daily ratings.
PMDD AND UNIPOLAR DEPRESSIVE
DISORDERS
Women are at approximately twice the risk of developing
major depressive disorder (MDD) compared with
men. The National Epidemiologic Survey on Alcoholism
and Related Conditions, a survey of more then 43 000
adults, found that the 12-month prevalence of MDD in
women is 6.87% and the lifetime prevalence 17.10%. 14
The high rate of MDD in women increases the likelihood
that women with MDD will also have PMDD or
PMS. It is the case that high rates of comorbidity between
either PMS or PMDD and past episodes of MDD have
been documented by a number of groups (see Yonkers, 15
Kim et al, 16 and Breaux et al 17 for reviews). Among
women who have prospectively confirmed PMS or
PMDD and are not in a current episode of MDD,
approximately 30–70% of them will have had a prior
episode of MDD. 18–25 Especially if rates are on the higher
end of this range, estimates such as these suggest shared
vulnerability between MDD and PMDD. However, these
estimates are drawn from clinical samples of women
with PMDD rather than non-treatment-seeking individuals
and, because patients with a larger number of
psychiatric conditions are more likely to seek treatment,
rates of comorbidity between the two conditions may
be inflated.
Conversely, estimates of concurrent non-seasonal
depressive disorders with PMDD are lower and fall
between 12% and 25%. 16 Part of the reason may be that
the symptoms required for the two conditions overlap
and, when an individual is symptomatic and suffering
from MDD, it may be difficult to detect premenstrual
worsening because of a ‘ceiling effect’. Some researchers
who compared rates of concurrent mood disorders in
women who did vs did not prospectively confirm a
diagnosis of PMS or PMDD, find higher rates of MDD
in the latter group although not all studies concur. 17,26–28
It is more difficult to detect cyclic symptom changes in
women who have moderate to severe symptoms than in
those who do not. Furthermore, women who retrospectively
endorse PMS or PMDD, but do not confirm daily
ratings of symptoms, seem particularly likely to have
MDD or a minor depressive syndrome that accounts
for their complaint. Rather than having comorbid conditions,
they may instead misattribute symptoms to the
premenstrual phase of the cycle, when they are, in fact,
chronic. The onset of menses can be a marker that
women may use as a reference point, increasing the likelihood
of recall bias. Alternatively, women may have
premenstrual exacerbation of a chronic mood disorder
that might be difficult to fully appreciate as separate
from the underlying condition. Estimates show that up
to 70% of women in clinical cohorts, who have a depressive
disorder, also identify problems with premenstrual
symptom exacerbation. 29–33 In a recent report, premenstrual
worsening of depressive symptoms were retrospectively
reported by 64% of a large cohort (n � 433)
of premenopausal women participating in an antidepressant
treatment trial, 33 suggesting a substantial clinical
problem.
The comorbidity between seasonal affective disorder
(SAD) and PMDD can be probed by assessing daily
ratings in SAD women during the summer. This sidesteps
potential problems with the ceiling effect, since individuals
with SAD are typically not symptomatic during
summer. In one such study, 34 46% of women with SAD
but only 2% of healthy controls confirmed symptoms
consistent with PMDD after daily ratings, suggesting a
strong association between the SAD and a premenstrual
disorder.
Symptom deterioration among women with depressive
disorders is also found among women who are not
necessarily treatment-seeking. In a comprehensive and
well-designed study, researchers explored premenstrual
exacerbation of depressive symptoms in a community
cohort by examining daily ratings over one to two menstrual
cycles. 35 The point prevalence for full or subclinical
depressive illness in the cohort of women was 6.5%.
Of that group, slightly over one-half (58%) felt worse
premenstrually. The majority of women experienced
deterioration in only one depressive symptom, which
was most commonly sleep (21%) and least commonly
thoughts of death or suicide (2%). Importantly, women
taking antidepressant medication were as likely as those
who were not taking antidepressants to experience premenstrual
exacerbation. Given that the medication most
often used to treat depression was a serotonin reuptake