The first Thursday in October is European Depression Day, a day for learning about one of the most common mental illnesses among the general population. In depression, there is a subgroup of patients who do not respond well to the usual treatments, and who suffer from what is known as treatment-resistant depression (TRD).
With the objective of determining the prevalence, economic burden, and social impact of this type of depression in our country, researchers of the Mental Health CIBER, headed by its scientific director, Eduard Vieta, head of the psychiatry and psychology department of Hospital Clínic’, Barcelona, and leader of the IDIBAPS Bipolar and depressive disorders group, and by Víctor Pérez Sola, of Hospital del Mar, Barcelona, with the collaboration of the Epidemiology CIBER and other experts, carried out a study which has been published in the Journal of Affective Disorders. According to the results, TRD has a mean incidence in Spain of 0.93/1000 people. This means that every year, 44,000 more people suffer from this form of depression.
According to data from the Global Data Exchange 2021, more than 270 million people in the world suffer from depression, of whom, 175 suffer from major depressive disorder (MDD); i.e., they present daily symptoms of depression for more than 2 weeks, such as depressive mood, reduced interest, eating and sleep disorders, feelings of guilt, and recurrent thoughts of death or suicide. In Europe, it affects 3.15% of the total population, more than 25 million people, and in Spain, MDD has a prevalence of 4%.
The researchers used an observational study based on the Spanish Big Pac database, electronic medical records of primary-care centers, hospitals, and outpatient clinics specific to mental health, from the Spanish public health care system, and data from the National Institute of Statistics (INE) on health care costs and disabilities.
In this way, the study analyzed a sample of 21,630 patients over 18 years of age (with a mean age of 53 years; 67.2% women) with major depressive disorder, of whom, 3559 met the criteria for treatment-resistant depression (i.e., in the first year, administration of 2 or more different antidepressants failed, including antipsychotic drugs such as lithium, in treatment periods of at least 90 days). The annual incidence of TRD in the study population between 2015 and 2017 was 0.59, 1.02, and 1.18 per 1000 people, respectively, with a mean of 0.93/1000.
This study estimated the economic impact of major depressive disorder, establishing the mean total costs per patients at €4147,90, with higher costs for patients with treatment-resistant depression (a mean of €6096).
As explained by the study coordinator, Eduard Vieta, “for the first time, we have established the economic impact of the disease, taking into account direct costs, loss of productivity, and permanent disability, and we found that the incidence in Spain is similar to recent data from other European countries, and that treatment-resistant depression is associated with greater use of resources and higher costs in comparison with patients who do respond to treatment”.
Higher mortality and suicide
Treatment-resistant depression is associated with worse quality of life, greater comorbidity, social and occupational disability, and worse therapeutic outcomes. The head of the CIBERSAM group at Hospital del Mar, Barcelona, Víctor Pérez Sola, also said that “the results of our study show that in the first year following diagnosis as many as one in every six patients has at least two changes of treatment, as an indication of TRD, and the costs associated with the disease, especially due to loss of occupational productivity and mortality (because it is associated with higher rates of comorbidity and suicide) were higher in these patients”.
Vieta said that “to the best of our knowledge, this is the first published study on the incidence of treatment-resistant depression in Spain based on real-life data, which makes it essential for physicians and for those responsible for health care policy to have updated information on this disease in its more complex forms”.
He concludes that “based on these data, our first concern is to correctly diagnose treatment-resistant depression for the wellbeing of the patients and their families, which also means reducing the economic impact of this disease”.
Víctor Pérez-Sola, Miquel Roca, Jordi Alonso, Andrea Gabilondo, Teresa Hernando, Antoni Sicras-Mainar, Aram Sicras-Navarro, Berta Herrera, Eduard Vieta PMID: 34509073 DOI: 10.1016 / j.jad.2021.08.036 J Affect Disord. 2021