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| Trends in Prescribing of Mental Health Drugs in England (Chart 1) |
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Just over two years ago the National Service Framework (NSF) for Mental Health was published. It sets national standards and defines service models for promoting mental health and treating mental illness. Most of the national programmes that underpin this NSF are now in place, for example:
- workforce planning, education and training
- modernising the care programme approach
- promoting mental health.
Much work is still however needed at a local level to improve the care of people with mental health problems. According to the NSF by April 2001 shared protocols between primary care and specialist services should have been implemented for the management of depression, anxiety disorders, schizophrenia, drug and alcohol dependence and for patients requiring psychological therapies.
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| Depression, eating disorders and anxiety disorders are the most common mental health problems a GP will have to manage. Prescribing of drugs used for mental health problems has increased over the last 5 years (chart 1), mainly due to increased use of antidepressants. In the quarter to June 2001 there were 5.9 million items for antidepressant drugs at a cost of £82.3 million. This rise could be due to a greater recognition of depression and an increased willingness to use drug therapy, alternatively increased prescribing of antidepressants for other indications such as analgesia, anxiety disorders and obsessive-compulsive disorder may be a factor. Spending on drugs used for mental health problems has risen at a faster rate than the volume of prescriptions (chart 2). Antipsychotic drugs have shown the highest growth in spending (£30.0 million, 1.3 million items for the quarter to June 2001). |
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| Trends in Spending on Mental Health Drugs in England (Chart 2) |
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Depression and Anxiety
Major depression affects around one sixth of the population in their lifetime whilst 2 to 3 times as many people may have depressive symptoms but not meet criteria for major depression. Such patients may have minor depression or dysthymia. Major depression can be divided into different grades of severity: mild to moderate and severe. Antidepressant drugs are effective in all grades of depression and there is no evidence of a clinically significant difference in the benefits of different antidepressant drugs1. Tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs) have different adverse effect profiles. Although SSRIs are better tolerated than TCAs in terms of overall withdrawal rates from trials, the absolute difference is small2. To reduce the risk of relapse, antidepressants should be continued for 4 to 6 months after recovery. When stopping therapy it is best to reduce the dose gradually over at least 2 to 4 weeks to minimise the risk of a discontinuation reaction. |
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| There is some evidence for the efficacy of St John's wort (Hypericum perforatum) in mild to moderately severe major depression, however in a recent trial in outpatients with major depression, there was no difference between St John's wort and placebo3. Its use is limited by the lack of a standardised preparation. St John's wort interacts with several prescribed medicines and the Committee on Safety of Medicines (CSM) has issued specific advice4. Patients taking antidepressant drugs should be advised not to use St John's wort. |
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Specific psychological treatments are another option for treating depression. There is evidence that cognitive therapy is effective both for depression and for generalised anxiety disorder (GAD)1. Clinical practice guidelines have been developed to aid decisions about which forms of psychological therapy are most appropriate for which patients5. Many patients with anxiety disorders also have depression and antidepressants may be more effective than benzodiazepines for GAD6. Long term use of benzodiazepines should be avoided due to the problems of dependence and the possibility of drugs being sold or stolen. Although they are a rapid and effective treatment for GAD, there is no good evidence that the short term benefits of benzodiazepines are maintained during long term treatment. Both benzodiazepines and antidepressants increase sedation, confusion and the risk of accidents. Buspirone produces fewer adverse effects than benzodiazepines but it has a slower onset of effect6.
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| The following prescribing data are for the quarter to June 2001. |
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| SSRIs are the most commonly prescribed antidepressant drugs (chart 3) accounting for 2.9 million items (£55.5million) per quarter. Prescribing of SSRIs has increased by 143% over the last 5 years whereas cost has risen by 66%. Fluoxetine, the most frequently prescribed SSRI, is now available off patent and its cost has fallen to £11.3 million (988,000 items) per quarter. There are slightly fewer prescriptions for paroxetine (933,000) but its cost has risen to £22.9 million per quarter. |
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| Tricyclic and related antidepressants account for 41% of antidepressant items but only 13% of cost (2.4 million items, £10.8 million per quarter). Amitriptyline is the most frequently prescribed TCA (1.1 million items, £2.3million per quarter). However more is spent on dothiepin (dosulepin) than amitritpyline (754,000 items, £3.0 million). |
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| Other antidepressants in chart 3 includes both newer drugs such as venlafaxine and older drugs such as the MAOIs. Venlafaxine is now 6% of all antidepressant prescribing (342,000 items per quarter) and 15% of costs (£12.1 million per quarter). |
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| Anxiolytic prescribing has shown little change over the last 5 years at 1.4 million items per quarter however cost has more than doubled to £2.4 million per quarter. Nearly three quarters of anxiolytic prescriptions are for diazepam whilst buspirone accounts for only 2% (1.0 million and 24,000 items per quarter respectively). Diazepam represents 46% of cost and buspirone 21% (£1.1 million and £503,000 per quarter respectively). |
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| Hypnotic prescribing has also remained at around the same level over the last 5 years (2.6 million items, £6.5 million per quarter). Prescribing of benzodiazepine hypnotics is falling although temazepam is still the most commonly prescribed hypnotic (42% of items, 25% of cost). Use of the newer hypnotics (zopiclone, zolpidem and zaleplon) has risen to 32% of all hypnotic items and 54% of cost. These newer hypnotics are only licensed for short term use and there have been case reports of dependence with long term use7. First line treatment for insomnia should be non-drug methods e.g. patient self-management aids. PRODIGY guidance contains suitable advice to share with patients (available at www.prodigy.nhs.uk). The CSM recommends use of benzodiazepines to treat insomnia only when it is severe, disabling or subjecting the individual to extreme distress. |
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| Cost for 28 Days Treatment |
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Schizophrenia
One in 100 people will develop schizophrenia in their lifetime. About three quarters of people with schizophrenia will suffer recurrent relapse and continued disability8. There is debate over the evidence for drug treatment of schizophrenia and larger trials, over longer periods, with well designed end points, including standardised, validated symptom scales are required. Antipsychotics are commonly divided into "typical" and "atypical" drugs. The atypical antipsychotics are thought to produce fewer extrapyramidal symptoms than the typical antipsychotics however trial evidence for this is weak8. Although the newer drugs are as effective as standard older antipsychotics it is not appropriate to recommend their use first line without clear evidence of overall superior efficacy or tolerability. |
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| Several antipsychotic drugs have been found to prolong the QT interval and have the propensity to cause arrhythmias such as torsade de pointes. Following reports of arrhythmias with thioridazine, the CSM has recommended that the risk:benefit of thioridazine would be favourable only as a second line treatment in schizophrenia in adults under specialist supervision and that there was insufficient evidence of efficacy to justify a favourable risk:benefit for use in the elderly for sedation and agitation9. The manufacturers of droperidol discontinued its distribution because of serious ventricular arrhythmias. |
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| Prescribing of Antidepressants in England (April - June 2001) Chart 3 |
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| Prescribing of thioridazine has fallen markedly since the CSM issued its recommendations. Chlorpromazine is now the most frequently prescribed typical antipsychotic (193,000 items, £395,000 per quarter). 37% of all antipsychotic prescriptions are for atypical drugs (412,000 per quarter) and these account for 89% of cost (£25.6 million per quarter). Risperidone is the most frequently prescribed atypical (201,000 items, £8.5 million per quarter) followed by olanzapine (161,000 items, £13.8 million per quarter). |
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References
- Geddes J, Butler R. Depressive disorders. Clinical Evidence 2001; 5: 652-667
- Anonymous. The drug treatment of depression in primary care. MeReC Bulletin 2000; 11: 33-36
- Anonymous. St John's wort: is it effective in depression? MeReC Extra 2001; 1: 1
- Breckenridge A. Important interactions between St John's wort (Hypericum perforatum) preparations and prescribed medicines. Letter from MCA/CSM 29 February 2000
- Dept. of Health. Treatment choice in psychological therapies and counselling. February 2001
- Gale C, Oakley-Browne M. Generalised anxiety disorder. Clinical Evidence 2001; 5: 668-678
- Jones IR, Sullivan G. Physical dependence on zopiclone: case reports. BMJ 1998; 316: 117
- McIntosh A, Lawrie S. Schizophrenia. Clinical Evidence 2001; 5: 695-716
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CSM/MCA. QT interval prolongation with antipsychotics. Current Problems in Pharmacovigilance 2001; 27: 4
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Summary
- Antidepressant drugs are effective in all grades of depression and there are no clinically significant differences in efficacy between different antidepressant drugs
- Cognitive therapy is effective for depression and for generalised anxiety disorder
- Long term use of benzodiazepines must be avoided due to the problem of dependence
- Zopiclone, zolpidem and zaleplon are only licensed for the short term treatment of insomnia
- The atypical antipsychotics may produce fewer extrapyramidal symptoms than the typical antipsychotics but better designed trials are required to confirm this before atypicals can be recommended as first line drugs
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