To our knowledge no other studies have evaluated the prescription of drugs for older persons with mental disorders other than dementia disorders, with a particular focus on the medical specialty of the prescribing physician. This study shows that GPs represented the main prescribers, whereas geriatricians and psychiatrists rarely prescribed drugs to older persons.
The study includes all older persons (≥65) in Sweden who received drugs dispensed at national pharmacies and thus includes the vast majority of the older population. The prevalence of prescriptions for drugs for mental disorders corresponds to approximately 7% of the older population in Sweden
. In fact, each year, more than half a million such prescriptions are dispensed to the older population, and the most commonly prescribed drugs are anxiolytics (benzodiazepines: oxazepam and diazepam) and tricyclic antidepressants (amitriptyline). Although previous studies on potentially inappropriate drugs for older persons suggested that benzodiazepines and tricyclic antidepressants are associated with a high risk of adverse effects and should be replaced with safer alternative drugs or therapies
[30, 31], the present study indicates that the use of benzodiazepines and tricyclic antidepressants was frequent. Approximately 60% of the older population was prescribed benzodiazepines, and only a minor decrease was observed over the course of the study. Furthermore, antidepressants such as mirtazapine are shown to involve high risk for adverse effects, including stroke or attempted suicide
, and despite its association with adverse effects in older persons, prescriptions for mirtazapine tended to increase over the years. These findings highlight the clinical relevance of thoroughly and regularly evaluating the continuous treatment of older persons.
Whereas approximately 85% of the older population received only one chemical substance intended for treating mental disorders, approximately 15% received two or more substances. Although this finding per se does not indicate polypharmacy or risk for adverse drug reactions, previous studies of the use of multiple drugs in older persons suggested that it may result in inferior self-rated health
 and increased depressive symptoms
The importance of expertise in geriatrics, gerontology and psychiatry when treating older persons in general and those with mental disorders in particular has been debated
[35–37]. Physicians without specialist education prescribed all types of psychotropics, across all age groups. As licensed physicians without specialist education in Sweden have undergone at most two weeks of training and education in geriatrics
, their prescribing behavior may be detrimental to the quality and adequacy of the treatment provided to older persons with mental disorders. The present study does, however, conclude that the majority of prescriptions for drugs for mental disorders were given by GPs, perhaps not surprising as GPs represent the majority of physicians in Sweden. GPs are recognized as an important part of psychiatric care
. In the present study, the tendency of GPs to prescribe drugs for mental disorders increased with the age of the patient. This corresponds to a previous study showing that although GPs are aware of the advantages of reducing the prescription of psychotropic drugs, they struggle to convince their older patients of the benefits of this
A previous study has shown that licensed physicians, other than psychiatrists, inaccurately diagnose mental disorders in older persons, and consequently prescribe inappropriate drugs
. Improved knowledge of geriatric psychiatry, including alternative treatments for older persons with mental disorders, would likely lead to the decrease in inappropriate prescription of drugs. However, although previous research has provided strong evidence on how to improve the care of older persons with mental disorders, translation into practice is rare
[41, 42]. Older persons with mental disorders are consequently subjected to lack of evidence-based care. To facilitate the translation of research into practice and to meet the need for specialists in geriatric psychiatry, it is essential to launch new extended educational programs for geriatricians and psychiatrists, as well as geriatric psychiatrists
. At present, only 60% trained geriatricians in Sweden continue to work with older persons throughout their careers
; low numbers of geriatricians indicates that most older persons are treated by other specialists and could explain the relatively low percentage of drugs prescribed by geriatricians. The proportion of prescriptions from geriatricians is overall low, but does increase up to 10% with increasing age of the patients; this may reflect the tendency of older persons to be treated by geriatricians as they approach 100 years of age. The proportion of prescriptions written by psychiatrists is also remarkably low: only 5% of the older persons aged 65 to 69 received prescriptions from psychiatrists and this percentage decreased further with increasing age.
The present study shows that women who are dispensed several substances tend to receive their prescriptions from geriatricians and psychiatrists to a higher extent than men. It has been demonstrated that women in old age are more likely to be affected by mental disorders
 and receive mental health care than men
; this may have increased the awareness of mental health issues among older women and led to more frequent referrals of women with mental disorders to specialists such as geriatricians and psychiatrists. This supports the necessity of continuing the discussion on gender differences in old age psychiatry and it becomes evident that new and improved approaches in the care of older persons are of utmost importance for providing the older population with adequate care and treatment.
Given the complexity and challenges entailed in providing care for older persons, an increase in the number of geriatric specialists with improved competence in psychiatry or the involvement of teams of different specialists may positively contribute to improving the quality of care. Communication between GPs and other specialists is vital for improving the care and treatment of older persons in general
 as well as older persons with mental disorders
[47, 48]. In order to assist healthcare personnel in providing the highest quality care to older persons with mental disorders, it is necessary to provide appropriate and effective drug treatment.
Strengths and limitations
The SPDR includes all prescriptions dispensed at national pharmacies and consequently includes the vast majority of the population in Sweden. The study population therefore consisted of approximately 200 000 older persons, which must be considered as a strength of this study. Nonetheless, this study had some limitations. Drugs that could be used for dementia disorders have been excluded which may have led to some types of selection bias. Due to the lack of diagnoses in the register, drug use was used as a proxy for diagnoses. Consequently, it is likely that some of the drugs that were excluded due to plausible use for dementia disorders may have been prescribed for an actual diagnosis and treatment for a mental disorder and should have been included in the study (diagnosis bias). The lack of diagnoses is a crucial limitation that may have decreased the validity of the results. To counteract this bias as far as possible, the treatment guidelines and recommendations set for each year of the study were thoroughly scrutinized and each disorder and ATC code was evaluated with the help of practicing psychiatrists in order to minimize inaccuracy. Drugs recommended as firsthand options for treating dementia disorders or symptoms during the years of the study were excluded to facilitate studying mental disorders besides dementia disorders. Consequently, this brought an unfortunate exclusion of SSRIs and antipsychotics. In addition, with the register lacking diagnoses the included drugs may have been prescribed on indications other than mental disorders; tricyclic antidepressants may be prescribed for e.g. neuropathic pain rather than depression. However, as this study aimed to present what medical specialties the prescribers hold rather than the prevalence of certain disorders, each disorder and connected drugs, including all antidepressants and antipsychotics, will be further analyzed in future studies.
With the character of the national register generalizations to older populations outside Sweden must be made with consideration. One important limitation is that the register does not include diagnoses. As a result of this limitation the interpretation of the results with respect to diagnoses and disorders may affect the outcome as the differences in prescribing rates by different specialists could be altered if diagnoses were to be included. However, the register does deliver reliable information about the competences of the prescribing physicians. Questions regarding alternative therapies and non-pharmacological treatment were not within the scope of this study. However, it would be of interest to study the frequency of prescriptions for non-pharmacological treatments by the various specialist categories. In addition, whether or not the prescribing rates by different specialists differ depending on the characteristics of the drug remain unclear and consequently future studies will include studying the prescribing rates when including e.g. SSRIs in the analyses. Possibly the prescribing differences between specialists and physicians without specialist education depend on specialists recurring more frequently to other classes of drugs different from those used by physicians without specialist education. Hence future studies may answer questions as to whether or not psychiatrists and/or geriatricians prescribe alternative treatments to a greater extent than other specialists or, alternatively, if the degree of patient contact with these specialists is overall low. In future studies we will also examine subsamples of the population and their prescriptions will be further scrutinized with respect to daily doses and comparisons to the general recommendations in order to further elucidate the subject.