When a trio of sleep specialists
noticed that 39% of patients presenting for treatment
of sleep apnea were also on anti-depressants —
often without significant improvement — they decided
to probe the association a little further. The researchers,
from the Tampa Sleep Center at University College Hospital,
found that Continual Positive Airway Pressure (CPAP),
a common treatment for the sleep disorder, led to improvements
in mood that would rival those of any anti-depressant
on the market. But it remains unclear if the patients
were depressed or just sleep-deprived. Their findings
appear in the September issue of Chest.
Before beginning treatment with
CPAP, a briefcase-sized device with a face mask that
keeps the airways open during sleep, the 50 patients
enrolled in the study averaged a score of 4.1 on the
Beck Depression Inventory (BDI). After four to six weeks
of CPAP at home, the average score had fallen to 1.0.
The more pronounced the depressive
symptoms, the more marked the improvement. All 25 patients
who classed as depressed in the first BDI showed significant
improvement (from an average 7.2 or "moderate depression"
to 1.8 "minimal signs of depression").
CHICKEN
OR EGG?
"It's possible these patients were simply misdiagnosed
in the first place," said study author Dr Daniel Schwartz.
"Or it's possible that they really were depressed, but
it was related to their sleep apnea, and once we treated
the cause we also treated the depression. All we can
really say for sure is that the symptoms they had were
consistently and radically improved."
So how can you tell which disorder
is at the heart of the problem? Dr Schwartz says one
way to distinguish between primary and secondary depression
is to look at sleep patterns. "You're more likely to
see things like early arousal [in depression]," he explained.
"Patients will wake up at five in the morning and not
get back to sleep. The apnea sufferer thinks he's sleeping
through the night, when in reality his sleep is being
frequently disrupted."
Respirologist Dr Pat Hanly, who
directs the Lung Association Sleep Centre at Calgary's
Foothills Hospital, often sees patients coming in to
the sleep clinic who are also taking anti-depressants.
"[These results] do suggest that when we see a patient
whose apnea responds well to the CPAP, it might be a
good time to re-evaluate the need for anti-depressants,"
he said.
CPAP
takes on all comers
In another study in the same issue of Chest, sleep specialists
from Harvard Medical School evaluated some of the most
common alternatives to CPAP.
The study confirmed a gathering
consensus that advancing the jaw by inserting a device
during sleep is of more use than more invasive surgical
and laser techniques, such as uvulopalatopharyngoplasty
(UPPP) and palatal stiffening.
But CPAP still wins the day. "The
real options for sleep apnea are CPAP, which is the
most effective, and mandibular advancement, which works
in most cases but not all," said Dr Hanly.
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