Depressive disorders,
which pose a substantial risk of death and disability and
are associated with suicide and poor work productivity, affect
about eight percent of adults. Moreover, close to twenty percent
of adults will suffer from some type of mood disorder that
requires treatment during their lifetime. Mood disorders often
have tragic results -- 15 percent of those affected commit
suicide.
Depression, a common
type of depressive disorder, is responsible for about 66 percent
of all suicides. The disease occurs twice as often in women
as in men and the risk increases if depression is present
in an immediate family member. As the leading cause of premature
death and disability in people between the ages of 18 and
44 years, it is surprising that there are no universally accepted
diagnostic criteria for depression.
There are often
errors in the diagnosis or treatment of the disease, and only
33 percent of depressed patients receive proper treatment.
These errors are associated with insufficient questioning
of the patient leading to diagnostic failure; failure to receive
adequate information regarding the patients symptoms from
family members; diagnosing a mood disorder and starting treatment
despite a lack of diagnostic criteria; attempting to blame
depression on stressful events, rather than diagnosing or
treating the disease.
One set of diagnostic
criteria commonly used to assess depression is known as "SIGECAPS"
(see table below). This stands for sleep, interest, guilt,
energy, concentration, appetite, psychomotor and suicide.
If four or more of these items are a concern, it indicates
major depression. However, other criteria, such as watching
for symptoms other than just mood change and obtaining supporting
information from family members, is important.
| Diagnostic
criteria for major depressive disorder* |
| A. |
The
patient has depressed mood (e.g., sad or empty feeling)
or loss of interest or pleasure most of the time
for 2 or more weeks plus 4 or more of hte following
symptoms: |
| |
Sleep
|
Insomnia
or hypersomnia nearly every day |
| |
Interest |
Markedly
diminshed interest or pleasure in nearly all activities
most of the time |
| |
Guilt |
Excessive
or inappropriate feelings of guilt or worthlessness
most of the time |
| |
Energy |
Loss
of energy or fatigue most of the time |
| |
Concentration |
Diminished
ability to think or concentrate; indecisiveness
most of the time |
| |
Appetite |
Increase
or decrease in appetite |
| |
Psychomotor |
Observed
psychomotor agitation/retardation |
| |
Suicide |
Recurrent
thoughts of death/suicidal ideation |
| B. |
The
symptoms do not meet crieteria for mixed episode
(major depressive episode and manic episode) |
| C. |
The
symptoms cause clinically significant distress or
impairment in social, occupational, or other improtant
areas of functioning |
| D. |
The
symptoms are not due to the direct physiological
effects of a substance (e.g., a drug of abuse, a
medication) or a general medical condition |
|
E.
|
The
symptoms are not better accounted for by bereavement
|
| *Adapted
from the Diagnostic and Statistical Manual of Mental
Disorders, 4th edition. |
|
The cause of depression
is thought to be a disruption of the brain’s neurochemistry.
Central norepinephrine neural pathways in the brain play a
role in vigilance, motivation and energy levels. These pathways
are associated with serotonin neural pathways, which are involved
in controlling impulsivity, and share a role with the dopamine
pathways in appetite, sex and aggression.
Depression is expected
to be the second leading cause of disability for people of
all ages by 2020. In general, an unhealthy lifestyle is more
common among those depressed than those who are not. Additionally,
children of those with depression are thought to have increased
rates of behavior problems and lower levels of self-esteem
than children with mothers who do not have depression.
In cases of moderate
to severe major depression, antidepressant drugs are often
used for treatment. Typically, about 60 percent of patients
respond to the treatment, with the amount reaching 80 percent
when a second drug is tried if the initial antidepressant
drug fails. The goal of treatment is a full remission of symptoms,
which may take up to four months. Patient recovery is not
linear, however, as symptoms may reoccur after resolving.
Current guidelines
suggest that antidepressant therapy should continue for at
least six months after recovery in order to lessen the chance
of a recurrence of depression, which occurs in more than 70
percent of patients.
Maintenance therapy,
using antidepressant therapy for an indefinite amount of time,
is considered as a treatment option for those who have additional
risk factors of depression, such as especially difficult episodes
or two or more episodes in a five-year period. The therapy’s
goal is to prevent recurrence of the illness, however, costs
and side effects of continued medication should be reviewed.
Another therapy,
electroconvulsive therapy (ECT) is an effective treatment
for about 60 percent to 80 percent of depressed patients who
receive it. ECT is often used in patients who have psychotic
features, display active suicidal tendencies and do not respond
to antidepressant chemotherapy. The reason why ECT is effective
remains unclear, but the therapy is typically associated with
a slowing in the prefrontal cortex, which likely affects a
fundamental neurobiologic process. ECT is usually given in
courses of 6 to 12 treatments, with improvements usually occurring
after the fourth treatment.
Phototherapy, or
light therapy, is particularly used for fall/winter seasonal
depressions. Treatment, typically prescribed for mild to moderate
cases, consists of exposure to full-sprectrum white light
for at least 30 minutes per day throughout the episode.
Another treatment
used for mild to moderate major depression is psychological
treatment. This type of intervention, including interpersonal
and cognitive behavioral therapies, has been found to be as
effective as antidepressant therapy. The treatment can be
administered individually or in a group setting and usually
lasts for 8 to 16 weekly sessions.
Combined treatments,
for example anti-depressants with psychological treatment,
are also used. The decision of which treatment to use should
be based on patient preference, advice from a clinician, cost,
practicality and success rates of different treatment types
within an individual patient.
Canadian
Medical Journal November 26, 2002