Research reportAntidepressant utilisation patterns and determinants of short-term and non-psychiatric use in the Finnish general adult population
Introduction
Use of antidepressants has increased in all Western countries during the past 15–20 years. In Finland, the increase between 1990 and 2006 was nearly 8-fold, from 7.09 DDD/1000 inhabitants/day in 1990 to 55.47 DDDs in 2006 (National Agency for Medicines, 2007). Similar trends have been reported elsewhere (Nomesco (Nordic Medico Statistical Committee), 2004, Paulose-Ram et al., 2007). Although consumption of antidepressant at the population level has increased notably, population-based studies with all psychotropics (Brugha et al., 2004) and antidepressants in particular (Helgason et al., 2004) suggest that increased prescribing may not have markedly improved the mental health of the population. In Scotland, for example, national development targets have already been made for reducing the increase in antidepressant use (www.isdscotland.org/IMHIP).
On the other hand, underutilisation of antidepressants among the depressed remains a constant concern since epidemiological evidence shows that depressive individuals do not receive the care they need (The Esemed/Mhedea 2000 investigators, 2004, Wang et al., 2005, Beck et al., 2005, Henriksson et al., 2006). Further, the impact of antidepressant utilisation rates on suicides is debated. Person-level (Tiihonen et al., 2006) and ecological (Korkeila et al., 2007) data from Finland suggest that use of antidepressants decreases suicide rates, however, this association has not been found in all countries (Helgason et al., 2004, Guaiana et al., 2005).
Widening indications for use can complicate an evaluation of the appropriate use of antidepressants. In addition to depressive disorders, selective serotonin reuptake inhibitors and other classes of newer antidepressants have been approved by the Finnish Agency for Medicines for treatment of panic disorder, social phobia, agoraphobia, generalized anxiety disorder, obsessive compulsive disorder (OCD) and post-traumatic stress disorder (Lääketietokeskus, 2007). Indications for tricyclic substances (mainly amitriptyline) include insomnia, chronic pain such as neuropathic pain, muscle tension, migraine, fibromyalgia and prophylactic medication for headache (Lääketietokeskus, 2007). Antidepressants are recommended for many anxiety disorders in clinical guidelines instead of anxiolytics (NICE (National Institute for Health and Clinical Excellence), 2004, Balwin et al., 2005).
Drug utilisation studies using general practice database (Gardarsdottir et al., 2007) and medical records (Henriksson et al., 2003) showed that the most common indications for antidepressant use were depression (45–66%), anxiety disorders (14–17%) , pain (3–14%) and sleeping disorders (5–9%). Less common indications in these two studies were: OCD, enuresis/incontinence, eating disorders, premenstrual syndrome, chronic fatigue syndrome, and dementia. Further, population-based studies (Beck et al., 2005, Trifirò et al., 2007) have deduced additional reasons for use based on the clinical characteristics of users: bipolar disorder, psychotic disorders, psychiatric disturbances associated with somatic disorders, and fibromyalgia. From these indications, antidepressants are commonly used for bipolar disorder, but this treatment is debated (Sachs et al., 2007).
Patten et al. (2007) estimated that about a third of antidepressant prescriptions by Canadian physicians are for reasons other than depression. Beck et al. (2005) showed over 40% of users had never had a major depressive episode and another Canadian study (Patten et al., 2005) that 42% of the population taking antidepressants did not have mood, anxiety or substance use disorder.
In psychiatric care, premature termination of antidepressant treatment has been a concern. According to a US study for the period 1996–2001 (Olfson et al., 2006), 42% of treatments for depression were discontinued within a month. In a regional Finnish study of psychiatric care, in 49% of cases antidepressant treatment was terminated before completion of the continuation phase, or in the early maintenance phase for those with > 3 lifetime episodes (Melartin et al., 2005). Clinical practice guidelines for depression recommend that antidepressant treatment should be continued for 4–6 months after remission (American Psychiatric Association, 2000, NICE (National Institute for Health and Clinical Excellence), 2007). For other indications, appropriate length of use is less clearly established.
In continuity studies, the interest has been mostly in explaining long-term use, while surprisingly, similar attention has not been given to short-term use (which is nearly always inappropriate). Further, in many cases the indications for use remain unclear. In our study, long-term utilisation data were available on antidepressants prescriptions via linkage between a population-based study and national registers, giving us the opportunity to study these questions. The aim of this study was to describe the utilisation patterns and determinants of antidepressant use in the general adult population. Specific aims were to study 1) determinants of short-term antidepressant use, and 2) the extent and determinants of antidepressant use that was not related to known psychiatric morbidity.
Section snippets
Methods
This study is based on a comprehensive, multidisciplinary national population-based survey, Health 2000, conducted in Finland from 2000–2001. The stratified cluster-sampling frame comprised adults aged 30 and over. Subjects aged 80 or over were oversampled (2:1). An initial random sample of 8028 persons was identified from the population register. Potential participants were given options to provide information in various ways, namely via home interviews and examinations, telephone interviews
Results
The prescription database showed that 7.4% (crude)/ 7.1% (weighted) ( 95% CI 6.8%–8.0%, n = 526/7112) of all respondents had used antidepressants during the year 2000, and 5.3% (4.8–5.8%) reported current use in the home interview. Of the current users, 27% used tricyclics and 73% SSRIs or other second-generation antidepressants.
Discussion
The annual prevalence of antidepressant use (7.1%) in the Finnish general population was higher than the annual prevalence of major depressive disorder alone (4.9%) but close to the combined prevalence (7.9%) of major depressive disorder or anxiety disorders (Pirkola et al., 2005). When the indication for treatment is unknown, these crude proportions don't guarantee optimal treatment. Only 30% of those with CIDI-diagnosed major depression and 33% with anxiety disorder used antidepressants
Role of funding source
Funding for this study was provided by the Academy of Finland which had no further role in the study process (design, analysis, interpretation, or writing).
Conflict of interest
None of the authors have conflict of interests that could influence this manuscript.
Acknowledgements
The study was supported by grant from the Academy of Finland.
References (36)
- et al.
Indications for antidepressant drug prescribing in general practice in the Netherlands
J. Affect Disord.
(2007) - et al.
Infrequent use of antidepressants in depressed individuals (an interview and prescription database study in a defined Swedish population 2001–2002)
Eur. Psychiatry
(2006) - et al.
Psychotropic medication consumption patterns in the UK general population
J. lin. pidemiol
(1998) Practice guideline for the treatment of patients with major depressive disorder
Am. J. Psychiatry
(2000)- et al.
Evidence-based guidelines for the pharmacological treatment of anxiety disorders: recommendations from the British Association for Psychopharmacology
J. Psychopharmacol.
(2005) - et al.
Antidepressant utilization in Canada
Soc. Psychiatr. Epidemiol.
(2005) - et al.
Trends in service use and treatment for mental disorders in adults throughout Great Britain
Br. J. Psychiatry
(2004) - et al.
Why people do not take their psychotropic drugs as prescribed: results of the 2000 National Psychiatric Morbidity Survey
Acta Psychiatr. Scand.
(2007) - et al.
Inappropriate prescribing for the elderly Americans in a large outpatient population
Arch. Intern. Med.
(2004)