Depression

Depression is a low mood or loss of interest, usually accompanied by one or more of the following: low energy, changes in appetite, weight or sleep pattern, poor concentration, feelings of guilt or worthlessness and suicidal ideas.¹ Adverse life events commonly precede all types of major depression, irrespective of the clinical picture and there is no clear relationship between apparent cause of depression and response to antidepressant drug treatment.²

• Depressive disorders are common. The prevalence of major depression in people seen in primary care is between 5% and 10%, and two to three times as many people have depressive symptoms but do not meet the criteria for major depression.³
• About two thirds of adults will at some time experience depressed mood of sufficient severity to influence their activities.⁴
• Most depressive states are at the mild to moderate end of the spectrum and it is these that are mainly seen in primary care.
• One study in Canada found that women were approximately twice as likely as men to experience a depressive episode within a lifetime.⁴
• Lifetime risk for major depression is 15% overall: 19% for women and 10% for men.⁵

Risk factors

• Past history of depression.
• Significant physical illnesses causing disability or pain.
• Other mental health problems, such as dementia.
• Depression is much commoner in people from the African-Caribbean, Asian, refugee and asylum seeker communities.

• A high index of suspicion is necessary. Only about half of people with major depression are identified as having this by their GP. People often present with mainly physical symptoms.⁶
• Screening for depression should be undertaken in primary care and general hospital settings for depression in high-risk groups, e.g. those with a past history of depression, significant physical illnesses causing disability, or other mental health problems such as dementia.¹
• Many people have a physical illness, diverting attention away from their mental state.⁵
• Especially in the elderly. depression may present as pseudodementia, with abnormalities of memory and behaviour that are typical of true dementia.
• Depression should be particularly suspected if there is a history of major depression, a family history of mood disorder or a history of suicide attempt.⁵
• Screening questions and self-report scales for the detection of depressive disorders are reasonably sensitive but not very specific. They are therefore most useful when a depressive disorder is suspected or in high-risk populations.²
• However the Patient Health Questionnaire (PHQ-9) is easy to use, self-administered and has been validated for use in Primary Care.^7,8
• GPs should consider asking their patients two questions to screen for depression.⁹ During the past month, have you:
  • Felt low, depressed or hopeless?
  • Had little interest or pleasure in doing things?
• The Hospital Anxiety and Depression Scale, when used in primary care, has 90% sensitivity and 86% specificity at picking up depression.²
• The Beck Depression Inventory is a screening questionnaire of 21 questions which is often used on patients by health care professionals.¹⁰
• People suspected of having depression, either clinically or from the results of screening questions or self-report scales, should be assessed for major depression according to DSM-IV criteria as listed below.
• Assessment should include assessment of suicide risk. Suicide ideation can develop at any time during treatment.

• Major depression is defined by the presence of at least five out of the following nine symptoms (and must include depressed mood and/or loss of interest or pleasure):
  • Depressed mood
  • Loss of interest or pleasure in almost all activities
  • Significant weight loss or gain, or change in appetite
  • Insomnia or hypersomnia
  • Psychomotor agitation or retardation (observable by others)
  • Fatigue or loss of energy
  • Feelings of worthlessness or excessive or inappropriate guilt
  • Diminished ability to think or concentrate, or indecisiveness
  • Recurrent thoughts of death (not just fear of dying) or suicidal thoughts/actions
• Symptoms must have been present for at least the last 2 weeks and cause clinically significant distress or impaired functioning.
• The symptoms are not due to a physical/organic factor (e.g. substance abuse) or illness and are not better explained by bereavement (although this can be complicated by major depression).
• Mild to moderate major depression ranges from a threshold number (five) of symptoms with minimal functional impairment through to marked symptoms and impairment of function.¹¹
• Severe major depression is characterised by the presence of all, or nearly all, DSM-IV depressive symptoms to a clinically severe degree, and marked functional impairment in all areas of life.¹¹

• Bipolar affective disorder
• Schizophrenia (depression may co-exist)
• Dementia may occasionally present as depression and vice versa
• Postnatal depression (clinical features are identical but suicidal ideas are less common)
• Seasonal affective disorder
• Bereavement: depressive symptoms begin within 2-3 weeks of a death (uncomplicated bereavement and major depression share many symptoms but active suicidal thoughts, psychotic symptoms and profound guilt are rare with uncomplicated bereavement)
• Drug adverse effects are an uncommon cause of depression. Medications that may cause depressed mood include:
  • Centrally acting antihypertensives (e.g. methyldopa)
  • Lipid soluble beta-blockers (e.g. propranolol)
  • Benzodiazepines or other central nervous system depressants
  • Progesterone contraceptives, especially medroxyprogesterone injection

• Dysthymia is a chronic depressive state of more than 2 years' duration, which does not meet full criteria for major depression and is not the consequence of a partially resolved major depression. People with dysthymia are likely to experience episodes of major depression.
• Dysthymia increases with age and affects about 10% of 55-64-year-olds. Lifetime risk is 4% for women and 2% for men.⁵
• Eating disorders: anorexia nervosa and bulimia nervosa.
• Substance misuse is frequently associated with depression.
• Other psychiatric conditions may coexist with depression (e.g. generalised anxiety disorder, panic disorder, obsessive-compulsive disorder, personality disorders).
• Any chronic disease e.g. Parkinson's disease, diabetes mellitus.

The management of depression is outlined in a separate article Managing Depression. Some view depression as a chronic illness on a par with hypertension and diabetes mellitus requiring a management model and monitoring.¹² The Government has recently announced additional money targeted to develop new local services for psychological therapies.¹³

Treatment of mild depression in primary care

• For patients with mild depression who do not want an intervention or who may recover with no intervention, a further assessment should be arranged, normally within 2 weeks (watchful waiting).
• Insomnia and anxiety management: consider advice on sleep hygiene and anxiety management.
• Exercise: advise patients of all ages with mild depression of the benefits of following a structured exercise programme, with up to 3 sessions per week of moderate duration (45 minutes to 1 hour) for between 10 and 12 weeks.
• For patients with mild depression, consider a guided self-help programme.
• Computerised cognitive behavioural therapy should be considered for the treatment of mild to moderate depression.¹⁴
• Psychological interventions:
  • In mild and moderate depression, consider psychological treatment specifically focused on depression, such as problem-solving therapy, brief cognitive behavioural therapy (CBT) and counselling of 6 to 8 sessions over 10 to 12 weeks.
• Antidepressants:
  • Antidepressants are not recommended for the initial treatment of mild depression, because the risk-benefit ratio is poor.
  • When mild depression persists after other interventions, or is associated with psychosocial and medical problems, consider use of an antidepressant.
  • If a patient with a history of moderate or severe depression presents with mild depression, consider use of an antidepressant.
  • When an antidepressant is to be prescribed, it should be a selective serotonin reuptake inhibitor (SSRI), because SSRIs are as effective as tricyclic antidepressants and are less likely to be discontinued because of side effects.
  • All patients prescribed antidepressants should be informed that, although the drugs are not associated with tolerance and craving, discontinuation or withdrawal symptoms may occur on stopping, missing doses or, occasionally, on reducing the dose of the drug. These symptoms are usually mild and self-limiting but can occasionally be severe, particularly if the drug is stopped abruptly.
• Review in mild depression; consider contacting all patients with mild depression who do not attend follow-up appointments.

Treatment of moderate to severe depression

• Psychological interventions, including computerised cognitive behavioural therapy are effective for moderate depression as indicated above.¹⁴
• When patients present initially with severe depression, a combination of antidepressants and individual CBT should be considered as the combination is more cost-effective than either treatment on its own.
• In moderate depression, offer antidepressant medication to all patients routinely, as well as discussing psychological interventions.
• Discuss the patient's fears of addiction or other concerns about medication. Warn about expected side effects to improve compliance.
• Inform patients about the delay in onset of effect, the time course of treatment and the need to take medication as prescribed. Make available written information appropriate to the patient's needs.
• Monitoring risk:
  • See patients who are considered to be at increased risk of suicide or who are younger than 30 years old 1 week after starting treatment. Monitor frequently until the risk is no longer significant.
  • If there is a high risk of suicide, prescribe a limited quantity of antidepressants.
  • If there is a high risk of suicide consider additional support such as more frequent contacts with primary care staff, or telephone contacts. Consider referral to secondary care or use of the Mental Health Act.
• Monitor for signs of akathisia, suicidal ideas, and increased anxiety and agitation, particularly in the early stages of treatment with an SSRI.
• Continuing treatment:
  • See patients who are not considered to be at increased risk of suicide 2 weeks after starting treatment and continue to review regularly as appropriate.
  • For patients with a first episode of moderate or severe depressive episode, continue antidepressants for at least 6 months after remission.
  • Patients who have had two or more depressive episodes in the recent past, and who have experienced significant functional impairment during the episodes, should be advised to continue antidepressants for 2 years.¹ A much longer duration of treatment may be required for some patients.
• Choice of antidepressants:
  • For routine care, use an SSRI because they are as effective as tricyclic antidepressants and less likely to be discontinued because of side effects.
  • Treatments such as dosulepin, phenelzine, combined antidepressants, and lithium augmentation of antidepressants should be initiated only by specialist mental healthcare professionals.
  • Venlafaxine should be initiated and managed only by specialist mental health medical practitioners.
  • St John's wort may be of benefit in mild or moderate depression, but its use should not be prescribed or advised because of uncertainty about appropriate doses, variation in the nature of preparations, and potential serious interactions with other drugs.
• For patients whose depression is treatment resistant, the combination of antidepressant medication with CBT should be considered.
• CBT should be considered for patients with recurrent depression who have relapsed despite antidepressant treatment, or who express a preference for psychological interventions.
• Stopping or reducing antidepressants:
  • Reduce doses gradually over a 4-week period; some people may require longer periods, and fluoxetine can usually be stopped over a shorter period.
  • For mild discontinuation/withdrawal symptoms, reassure the patient and monitor symptoms. For severe symptoms, consider reintroducing the original antidepressant at the effective dose (or another antidepressant with a longer half-life from the same class) and reduce gradually while monitoring symptoms.
• Electroconvulsive therapy (ECT):
  • ECT should be used to gain fast and short-term improvement of severe symptoms after all other treatment options have failed, or when the situation is thought to be life-threatening.¹⁵

• Depression is a major cause of impaired quality of life, reduced productivity, and increased mortality. Social difficulties are common (e.g. social stigma, loss of employment, marital break-up). People with depression are at increased risk of suicide.
• Associated problems, such as anxiety symptoms and substance misuse, may cause further disability.

• The outlook varies with the severity of the condition.
• For major depression: approximately 80% of people who have received psychiatric care for an episode will have at least one more episode in their lifetime, with a median of four episodes. The outcome for those seen in primary care also seems to be poor, with only about a third remaining well over 11 years and about 20% having a chronic course.¹¹
• For dysthymia, the long-term outlook is poor, with only 40-50% well at 1-year follow-up.⁴