PREVENTING MENTAL DISORDERS
In our research focus "Prevention", the PROTECT Lab deals with
the development of psychological interventions for the prevention of mental illness, with a focus on the prevention of depression
the evaluation of the effectiveness of interventions for the prevention of mental disorders (randomized controlled trials, meta-analyses, individual patient data meta-analyses)
the cost-effectiveness of prevention
the identification of mechanisms of action of preventive psychological interventions
Indications: for whom preventive psychological interventions are effective, and for whom not
Strategies to improve the uptake of evidence-based interventions in high-risk groups
WHY DEAL WITH PREVENTION?
Mental Disorders, with an estimated life-time and 12-month prevalence rate between 18,1-36,1% and 9,8-19,1% (Kessler et al., 2009) are very common. Mental Disorders are one of the leading causes for disability (Whiteford et al., 2013), and lead to a high disease burden, with increased risk for developing chronic somatic conditions and related mortality (Cuijpers & Smit, 2002; Saarni et al., 2007; Üstün, Ayuso-Mateos, Chatterji, Mathers, & Murray, 2004). Economic consequences are also substantial, caused by medical costs, disability or loss of productivity at work (Berto, D’Ilario, Ruffo, Virgilio, & Rizzo, 2000; Greenberg & Birnbaum, 2005; Smit et al., 2006).
In the last decades, a numerous evidence-based interventions were developed to treat mental disorders (Cuijpers, van Straten, Andersson, & van Oppen, 2008; Hofmann & Smits, 2008). However, even when considering a hypothetical scenario of 100% coverage with state-of-the-art effective treatment options, the current burden of disease of mental disorders can only be reduced by 1/3 (Andrews, Issakidis, Sanderson, Corry, & Lapsley, 2004). In fact, only half of all mental disorder cases are detected as such and treated (Kohn, Saxena, Levav, & Saraceno, 2004). Thus, current attentions are increasingly focusing on the prevention of mental disorders.
WHAT IS PREVENTION?
Most researchers and practitioners define prevention as those interventions which are conducted before people meet the formal criteria of a depressive disorder according to the DSM-5. There are three types of prevention, universal, selective and indicated prevention.
Acute and maintenance treatment are aimed at people who have established disorders meeting diagnostic criteria. Three types of prevention can be discerned:
universal prevention, which is aimed at the general population or parts of the general population, regardless of whether they have a higher than average risk of developing a disorder (e.g., school programs or mass media campaigns);
selective prevention which is aimed at high-risk groups, who have not yet developed a mental disorder; and
indicated prevention which is aimed at individuals who have some symptoms of a mental disorder but do not meet diagnostic criteria.
Despite effective treatment options, mental disorders can have a deleterious impact on the quality of life of affected individuals and their loved ones.
Depression is a highly prevalent condition, affecting about 150 million people worldwide at each moment in time.
Currently, depressive disorders are the third disorder worldwide in terms of disease burden, and will be the disorder with the highest disease burden in high-income countries in 2030. Furthermore, depressive disorders are associated with huge losses in quality of life in patients and their relatives, with increased mortality rates, with high levels of service use, and with enormous economic costs.
Shifting from curing to preventing
Much of the disease burden, and economic costs of depressive disorders is associated with the very high incidence of depression. About 48% of all patients with a depressive disorder in the past year, indicate that they had that depression for the first time in their lives, although some of them may have been cases of recurrent depression. The same is true for the economic costs of depressive illnesses. About 47% of the costs of prevalent cases is associated with incident cases. While mental health care is mainly aimed at treating depressed patients, hardly anything is done about the vast influx of new cases who develop a depression for the first time in their lives.
Overall Effects of Depression Prevention Programs
After the first studies were conducted in the 1990’s, the number of studies has increased rapidly since 2000.
A recent meta-analysis of these studies (van Zoonen et al., 2014) found a total of thirty-two studies in which subjects with a depressive disorder according to DSM-criteria at baseline were excluded, and only subjects with no formal depressive disorder were included.
In all these studies, it was examined whether the incidence rate of mental disorders was reduced in the recipients of preventive interventions compared to subjects who did not participate in such an intervention. The overall incidence rate ratio was 0.79 (95% CI: 0.69~0.91). The incidence rate ratio is the incidence rate of developing a depressive disorder in experimental subjects relative to the incidence rate in control subjects. An incidence rate ratio of 0.79 indicates a reduction of the risk of developing a depressive disorder in the next year of about 21% compared to people in the control groups. This study indicates that prevention of new cases of depressive disorders seems to be possible and may have become a realistic strategy to reduce the enormous burden of these disorders, next to treatment of existing depressive disorders.
Since then, even more randomized trials have shown that preventive interventions are effective in reducing the incidence of depressive disorders.