By 2020, depression will be second only to cardiovascular diseases as the world's most common disabling disease. Prevalence may be as high as 30 per cent in older people and 20 per cent in people with chronic physical problems such as diabetes and heart disease.
The starting point for effective treatment is recognition of the problem and the first point of access is usually primary care.
Explore and assess
The 2009 NICE guideline on dep- ression suggests a comprehensive assessment be undertaken to make the diagnosis, including the use of a validated measure such as the patient health questionnaire (PHQ-9)1. In addition, it is vital the GP explores with the patient any suicidal ideas or experience of self-harm, and strategies to help prevent the patient acting on such ideas.
The GP must explore the patient's views on their problems and whether a label of depression is acceptable to them, then discuss management options, which will depend on the comprehensive assessment, the PHQ-9 score, if used, and on the patient's own preferences.
The stepped-care model in the updated NICE guideline uses the term 'active monitoring'
for people who may recover with no formal intervention, for those with mild depression who prefer not to have an intervention, and for people with subthreshold depressive symptoms who request an intervention.
Active monitoring includes psycho-education, advice about sleep hygiene, activity, alcohol and drug use, and active follow-up. Active follow-up and support is vital for all patients with depression, rather than being restricted to step 1. For patients who have a mild to moderate depressive illness, step 2 states that referral for low-intensity psychosocial interventions should be offered to the patient.
Pharmacological treatments are indicated in steps 3 and 4 of the stepped-care model, and in step 2 for people with a past history of moderate or severe depression, initial presentation of subthreshold depressive symptoms lasting for at least two years, and subthreshold depressive symptoms or mild depression persisting after other interventions.
The GP is responsible for negotiating drug treatment with the patient, initiating the prescription and monitoring progress on antidepressant medication. Although St John's wort may be of benefit in mild to moderate depression, GPs should not prescribe it because of uncertainty about doses, persistence of effect, variation in preparations and potentially serious interactions with other drugs. It is also vital the GP asks the patient whether they have purchased it over the counter.
The GP needs to explore the patient's views on tablets, and antidepressants in particular, in order to dispel any myths.
If the patient agrees to try an antidepressant, it is important to match the tablet to the patient, taking account of tolerability, safety, side-effects, drug interactions and contraindications, and previous patient experience of such drugs.
Involving the patient in treatment decisions is a fundamental principle. The process of engagement in treatment (concordance) emphasises the importance of the relationship between patient and prescriber.
Patients may fail to take their antidepressants because of persistent attribution of all symptoms to physical illness. Set aside time to optimally manage current physical illness and to emphasise that depression too can be considered an illness, and that it is common, treatable and not a sign of moral weakness.
Reassurance is often needed that antidepressants are not addictive, and that, particularly in older people, depression is not a harbinger of dementia.
Patients must also be told not to expect immediate results and be advised of common side- effects. It is important to tell the patient at the outset about the risk of discontinuation symptoms. Usually antidepressants should be continued for up to 12 months after recovery, and longer in recurrent depression.
The issue of switching antidepressants is complex and the evidence is evolving. Received wisdom has been that antidepressants take two to four weeks to begin to work. But it has now been shown in clinical trials that improvement can start immediately, with the greatest improvement in the first week and the curve flattening off thereafter.
It is important to recognise that although the curve flattens, some people continue to improve. The assessment of the literature is influenced by the duration of follow-up. In some studies (with longer follow-up) some patients continue to respond at 12 weeks and beyond. The rate and degree of improvement also appears to be influenced by frequency of follow- up. This is where the role of the GP is particularly important.
The NICE depression guideline states: 'If response is absent or minimal after three to four weeks of treatment with a therapeutic dose of an antidepressant, increase the level of support (for example, by weekly face-to-face or telephone contact) and consider increasing the dose in line with the summary of product characteristics if there are no significant side-effects or switching to another antidepressant.'
It adds: 'If the person's depression shows some improvement by four weeks, continue treatment for another two to four weeks. Consider switching to another antidepressant if response is still not adequate.'
When considering changing the drug or dose, the GP should be aware that doing so too early could mean rejection of an effective treatment, and increasing the dose too soon could lead to patients being maintained on higher than needed doses over a prolonged period with associated side-effects or treatment discontinuation. However, delaying treatment change too long could prolong the period of depression, with a loss of faith in the treatment by the patient and increase depression-related morbidity and even mortality.
Balanced against this is the evidence of similar levels of effectiveness across the antidepressants. As Pilling et al (2009) state: 'Evidence for the relative advantage of switching within or between classes is weak.'2
The overall conclusion is that choice should largely depend on side-effects, patient preference and previous experience of treatments, propensity to cause discontinuation symptoms and safety in overdose.
Moreover, there is evidence, from clinical trials, qualitative studies and the stakeholder con-tributions published in the full NICE guideline, that regular contact with the GP and referral for psychological therapies/psy- chosocial support are valued by people with depression and eff-ective in improving outcomes.
There is therefore a danger in focusing too much on the antidepressant.
- Professor Chew-Graham is a GP, professor of primary care at the University of Manchester, and RCGP clinical champion for mental health
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1. NICE. Depression: the treatment and management of depression in adults (update). CG90. London, NICE, 2009.
2. Pilling S, Anderson I, Goldberg D et al. Depression in adults, including those with a chronic physical health problem: summary of NICE guidance. BMJ 2009; 339: b4108.