Depression

last authored: Sept 2009, David LaPierre
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Introduction

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.

 

 

Causes and Risk Factors

"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.

 

 

Signs, Symptoms, and Diagnosis

Once tests are done to rule out other causes of symptoms, a clinical diagnosis can be made.

  • history
  • physical exam
  • differential diagnosis

History

 

Screening questions

Screening should only be carried out only if there is sufficent resources to provide follow-up (USPSTF, 2009)

 

Screening qustions include:

  • Are you depressed?
  • Have you lost interest or pleasure in things you normally like to do?
  • Do you have troubles sleeping?

 

Diagnosis of Major Depressive Disorder

At least one of the following:

  • depressed mood
  • anhedonia

At least four of the following minor symptoms (SIG-E-CAPS):

  • Sleep disturbance (insomnia or hypersomnia)
  • loss of Interests
  • Guilt
  • decreased Energy
  • trouble Concentrating or impaired memory
  • change in Appetite
  • Psychomotor agitation or retardation
  • Suicidal ideation

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.

Physical Exam

Differential Diagnosis

Other psychiatric disorders:

  • anxiety
  • personality disorders
  • bipolar disorder
  • schizoaffective disorder
  • SAD
  • aubstance abuse/withdrawal

Secondary Causes of Mood Disorders

  • infections: encephalitis/meningitis, hepatitis, pneumonia, TB, syphilis
  • endocrine: menopause, diabetes,hypothyriodism, hyperthyroidism, hypopituitarism, SIADH
  • metabolic: porphyria, Wilson's disease
  • vitamin disorders: Wernicke's, beriberi, pellagra, pernicious anemia
  • collagen vascular diseases: SLE, polyarteritis nodosa
  • neoplastic: pancreatic cancer, carcinoid, pheochromocytoma
  • cardiovascular: cardiomyopathy, CHF, MI, CVA
  • neurologic: Huntington's disease, multiple sclerosis, tuberous sclerosis, degenerative conditions (vascular, Alzheimer's)
  • drugs: antihypertensives, antiparkinsonian, hormones, steroids, antituberculous, interferon, antineoplastic medications, benzodiazepines

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Subtypes of Depression

There are different flavours to depression, and these can often fall into discrete types:

  • seasonal
  • melancholic
  • atypical
  • postpartum
  • psychotic
  • catatonic

Seasonal

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.

Melancholic

either a loss of

  • loss of pleasure in all, or almost all, activities
  • lack of reactivity to usually pleasurable stimuli

and three or more of the following

  • distinct anhedonia
  • early morning waking
  • anorexia
  • excessive guilt

Atypical

mood reactivity, and two or more of the following:

 

  • significant weight gain or increase in appetite
  • hypersomnia
  • leaden paralysis
  • long-standing of interpersonal rejection sensitivity
  • MAOIs

Postpartum

  • It can be difficulty illness from times of adjustment difficulty or baby blues.
  • Severe persitent, progressive. Interferes with function.
  • Peaks at 4-6 weeks and 4-6 months.
  • High levels of co-morbid anxiety and irritability, with excessive worry.
  • Prominent cognitive dysfunction.
  • New obsessive thoughts and images can arise.
  • Suicide is not as common as escape fantasies
  • Increased risk of prior depression or premenstrual dysphoria, family history, and lack of social supports

Psychotic

  • more commonly delusions than hallucinations
  • often mood congruent

Catatonic

at least two of the following:

  • motoric immobility, with catalepsy or stupor
  • excessive motoric activity, apparently purposeless and not influenced by external stimuli
  • extreme negativism (apparently motiveless resistance to movement) or mutism
  • peculiarities of voluntary movement as evidenced by posturing, stereotyped movements, or prominent mannerisms or grimacing
  • echopraxia or echolalia

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Pathophysiology

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.

 

Social and Environmental Factors

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.

 

Amine Hypothesis

Depression is thought to involve brain amines, including norepinephrine, serotonin, and dopamine. A functional decrease in synaptic transmission of these neutrotransmitters results in depression.

 

Neurogenesis Hypothesis

hippocampus atrophy may be an important part of depression, first found in PTSD

Stress decreases neurotrpophins (ie BDNF) and neurogenesis in the hippocampus

Genetics

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.

 

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Antidepressants

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.

 

Treatment Goals

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.

 

Refractory Depression

When treating refractory depression (6-8 weeks of treatment), attempt to:

 

 

 

 

Counselling and Psychotherapy

 

Mental Hygeine basics

proper exercise, diet, sleep, and education (ie "the Feeling Good Handbook")

 

Psychotherapy

Cognitive behavioural therapy (CBT), interpersonal therapy, or psychodynamic therapy can be helpful for treating depression.

 

Other Techniques

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.

 

 

 

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Consequences and Course

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.

 

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The Patient

 

 

 

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Health Care Team

 

 

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Community Involvement

 

 

 

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Resources and References

 

Gill D, Hatcher S. 2004.

Gilbody S, Bower P, Fletcher J, Richards D, Sutton AJ. 2006. Collaborative care for depression: a cumulative meta-analysis and review of longer-term outcomes. Arch Intern Med. 166:2314-21.

 

Katon W, Unutzer J. 2006. Collaborative care models for depression: time to move from evidence to practice [Editorial]. Arch Intern Med. 166:2304-6.

 

USPSTF. 2009. Screening for depression in adults: U.S. preventive services task force recommendation statement. Ann Intern Med. 151(11):784-92.