Show Summary Details
Page of

Anxiety and depression 

Anxiety and depression

Anxiety and depression

Lydia Chwastiak

and Wayne J. Katon

Page of

PRINTED FROM OXFORD MEDICINE ONLINE ( © Oxford University Press, 2015. All Rights Reserved. Under the terms of the licence agreement, an individual user may print out a PDF of a single chapter of a title in Oxford Medicine Online for personal use (for details see Privacy Policy).

date: 27 April 2017

Depression is common, with point prevalence in Western industrialized nations about 3% for men and 7% for women, and lifetime risk is about 10% for men and 20% for women. Depression is the leading cause of years lived with disability. Physicians fail to make an accurate diagnosis in at least half of those with depressive or anxiety disorders.

Pathophysiological hypotheses involve abnormalities in the hypothalamic–pituitary axis, levels of particular neurotransmitters (particularly noradrenaline, serotonin, and dopamine), and neuroanatomical changes.

Clinical features

Patients with depression or anxiety initially present with physical complaints 50 to 70% of the time, and these conditions are associated with an amplification of physical symptoms, additional functional impairment, and a decreased ability to adhere to medication and important lifestyle changes (exercise and diet) in patients with chronic medical illness.

Major depressive episodes—these last at least 2 weeks and are characterized by at least one of the two primary criteria—(1) depressed mood, or (2) loss of interest or pleasure in nearly all activities—together with at least five of nine other criteria.

Panic attacks—these are characterized by the sudden onset of intense apprehension, fear or terror, and by the abrupt development (within 10 min) of at least four of a number of symptoms.

Generalized anxiety disorder—this is characterized by constant, nonepisodic anxiety that affects patients for more than 6 months and interferes with normal function.


Patients should be reassured: (1) that they are not ‘crazy’, nor are their symptoms a manifestation of their own failure or shortcomings; (2) with proper treatment, these disorders almost always improve or remit, but relapses and recurrences can occur and so follow-up is essential; (3) a variety of treatments are available.

Psychosocial interventions—these are effective for ambulatory medical patients with psychiatric disorders, the three short-term psychotherapies used to specifically target the symptoms of major depression being cognitive behavioural therapy, interpersonal psychotherapy, and problem solving therapy.

Antidepressant therapy—the decision to prescribe should be based on the number of symptoms, the level of dysfunction, and previous episodes of depression or anxiety. The different classes of antidepressant drugs show virtually equivalent efficacy, hence the choice of medication should be made on issues such as side effects, cost, adherence, and physician familiarity and comfort with prescribing particular agents. The selective serotonin reuptake inhibitors (SSRIs) have become the first-line treatment for major depression, dysthymia, and panic disorder, primarily because their improved side effect profiles are associated with improved adherence to treatment. About 40 to 50% of patients with major depression respond to an antidepressant within 3 weeks after reaching a therapeutic plasma level, and up to 80% will respond if initial nonresponders are switched to another class of antidepressant, or with augmentation strategies using additional medication or psychotherapy. Treatment should be continued for between 6 and 9 months after a first major depressive episode. Pharmacotherapy should be discontinued slowly over a period of 7 to 21 days: if tapered too quickly, almost all antidepressants can produce withdrawal syndromes.

Electroconvulsive therapy (ECT)—this remains the most effective treatment available for depression: it can be life-saving in some cases, and in frail older patients it may be safer than antidepressants.

Prognosis and need for specialist referral

Many patients (30–40%) who respond to treatment remain at substantial risk of relapse during the subsequent 12 months, with risk factors for relapse being: (1) persistence of subthreshold depressive symptoms; (2) history of three or more previous episodes of major depression; and (3) chronic mood symptoms for more than 2 years.

Referral to a psychiatrist should be considered when: (1) the physician is confused about the primary diagnosis; (2) adequate treatment does not lead to an improvement in symptoms within 10 to 12 weeks, or several medication trials have failed; (3) there is suicidal behaviour.

Access to the complete content on Oxford Medicine Online requires a subscription or purchase. Public users are able to search the site and view the abstracts for each book and chapter without a subscription.

Please subscribe or login to access full text content.

If you have purchased a print title that contains an access token, please see the token for information about how to register your code.

For questions on access or troubleshooting, please check our FAQs, and if you can't find the answer there, please contact us.