last authored: Sept 2009, David LaPierre
las
Depression (major depressive disorder in the DSM-IV) is a description of symptoms focused around poor self-worth, with attention fcused inwards. Depression describes these feelings and behaviours, however brief, while major depressive disorder describes symptoms of sufficient magnitude and duration to classify it as a disorder. Dysphoria can be confusing; often people don't know how they are feeling.
Depression is very common, with a prevalence of 4-8 per 100 adults, though an average annual incidence of 2-3 per 1000 adults. Depression is thusly a chronic disease, though also episodic. Lifetime risk is 10-25% for women and 5-12% in men. It is preceded by dysthymia in 10-25%. Average age of onset is mid 20's, though the mean age of onset is 30.
Depression can appear as a variety of non-specific symptoms, such as chronic fatigue or pain. Depression is often associated with anxiety disorders. Onset of episodes can be gradual or abrupt. For many, depression is a chronic recurrent illness, with the median number of lifetime episodes being 5. Up to 2/3 of patients may not receive appropriate treatment for their depression.
"Depression can seem like a black hole from which there is no escape"
Robert King, artist
Depression is often an unhealthy response to anxiety in which emotions are internalized and directed inwards. This can often follow significant life events which trigger feelings of low self-worth or hopelessness. (family factors: 14% risk (RR = 3-4).
A lack of external resiliency - supports such as family, friends, co-workers - can significantly predispose a person to depression, and risk factors increasing vulnerability include lack of confiding relationship, losing mother, lack of self esteem, or learned helplessness.
Common symptoms and disorders occurring with depression include anxiety disorders, substance abuse, eating disorders, and personality disorders.
In seniors, risk factors include: female, single or widowed, stressful life events, major illness.
Once tests are done to rule out other causes of symptoms, a clinical diagnosis can be made.
Screening should only be carried out only if there is sufficent resources to provide follow-up (USPSTF, 2009)
Screening qustions include:
At least one of the following:
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At least four of the following minor symptoms (SIG-E-CAPS):
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Major depressive disorder should be distinguished from bipolar disorder through the absence of manic or hypomanic episodes.
In the elderly, depressed mood may be less prominent, they are more likely to express somatic compaints (over half with hypochondriacal sx), less likely to feel gulity, cog imparment or psychosis (somatic, nihilism, persecution) is more common.
Late-onset depression is more likely to be associated with cognitive impairment or white matter changes.
Other psychiatric disorders:
There are different flavours to depression, and these can often fall into discrete types:
Seasonal depression, or seasonal affective disorder (SAD), has a pattern of onset the same each year. This is most often in the fall or winter.
either a loss of
and three or more of the following
mood reactivity, and two or more of the following:
at least two of the following:
Depression is a very complicated, multifactorial disease. It can be thought of as a dysregulation of rhythms, or as a shutting down of the psychological system.
Patients will not first think about biology as a cause of depression; they will first need you to talk about social, environmental, and personal factors.
Low self-esteem, negative thinking, and life stressors (ie loss) can all contribute to depression.
Depression is thought to involve brain amines, including norepinephrine, serotonin, and dopamine. A functional decrease in synaptic transmission of these neutrotransmitters results in depression.
hippocampus atrophy may be an important part of depression, first found in PTSD
Stress decreases neurotrpophins (ie BDNF) and neurogenesis in the hippocampus
Depression concordance rates of monozygotic twins are 65-75%, and for dizygotic twins, 14-19%. Serotonin transporter genes may be imnolved.
Some people may have neurochemistry that is hormone sensitive.
Antidepressants are important drugs for treating depression (Gill and Hatcher, 2004).
After initiating treatment, sleep and appetite come back first, concentration next, and mood last.
Consider affordability, history of prior response, side effect profile, depression subtype, drug interactions, medical comorbidity, clinician and patient preference, patient age, and fertility status.
short-term (8-12 weeks)
long term (>3 months)
end of treatment
As the biology is thought to be altered for 6-12 months, following symptom resolution, continuation therapy should be continued to prevent relapse.
Patients with the following risk factors should be maintained for at least two years: older age; frequent, recurrent, or chronic episodes; difficult-to-treat or severe episodes; psychotic features.
Assess patient status, therapeutic response, and adverse effects of antidepressant therapy on a regular basis beginning within 1 to 2 weeks of initiation of therapy.
When treating refractory depression (6-8 weeks of treatment), attempt to:
proper exercise, diet, sleep, and education (ie "the Feeling Good Handbook")
Cognitive behavioural therapy (CBT), interpersonal therapy, or psychodynamic therapy can be helpful for treating depression.
If depression is treatment-resistant, always review the diagnosis. Optimize the antidepressant by increasing the dose as tolerated before switching to an alternate agent. Consider augmenting with lithium or T3, and as a last resort, consider adding an antidepressant.
One year after diagnosis, without treatment, 40% of individuals have symptoms severe enough to be termed 'major depression' 20% have some symptoms, and 40% have no mood disorder.
Gill D, Hatcher S. 2004.
USPSTF. 2009. Screening for depression in adults: U.S. preventive services task force recommendation statement. Ann Intern Med. 151(11):784-92.