In the majority of western societies, anxiety disorders are considered the most common mental health problem (Craske et al., 2017). Data from the World Mental Health Survey suggests that one in four individuals are likely to suffer from a type of anxiety disorder at one point in their life (Kessler et al., 2007). Despite this, anxiety disorders are often left undiagnosed and untreated, up until several years after the onset of symptoms (Wang et al., 2007). Most anxiety disorders typically occur during childhood or adolescent and if left untreated, can become chronic and lead to a range of other mental health difficulties, including depression and substance misuse.

In past years, there have been significant developments in the treatment of anxiety disorders and currently, there are many psychological and pharmacological treatments that are considered effective. Nonetheless, treatment alone is not sufficient to eliminate the burden of disease. We must work towards lowering the incidence of new cases through the use of preventative methods.

To date, most systematic reviews and/or meta-analyses on the prevention of anxiety disorders have been conducted in young populations (i.e. children and adolescents). Of the studies conducted in adults, the focus has tended to be on specific anxiety disorders or specific types of interventions. This study therefore aimed to evaluate the effectiveness of psychological and/or educational interventions in preventing anxiety across the lifespan.

Methods

From the outset of this study up until March 2017, a systematic search of six electronic databases was conducted, searching for studies that:

• Were randomised controlled trials (RCTs);
• Included treatment-as-usual, no intervention, wait-list control, or attention control as the comparison intervention;
• Assessed the effectiveness of preventative psychological and/or educational interventions for anxiety in varying populations free of anxiety at baseline;
• Made use of standardised interviews or validated symptom scales to assess the incidence of new cases of anxiety disorders and/or the reduction of anxiety symptoms.

This systematic search was complemented by hand-searching of reference lists in other articles, and by drawing on the knowledge of experts in the field. Studies were not excluded on the basis of participant demographics, settings, or languages. There was also no restriction on the date of study publication. In addition, although most types of anxiety disorder were considered, studies of post traumatic stress disorder were excluded, as it is difficult to distinguish treatment from prevention in this case.

In total, 3,273 abstracts were reviewed, 131 were selected for full review, and 29 met the inclusion criteria. Pooled standardised mean differences were calculated using random-effect models.

Results

The 29 RCTs included in this review represented a total of 10,430 patients, including children, adolescents, adults and elderly individuals, from 11 countries.

The majority of RCTs (69%) were published in or after 2010, suggesting that research in this field has been increasing in recent years. In addition, of the 29 RCTs included in this review, most (86%) were trialling interventions based on the foundations of cognitive behavioural therapy (CBT), with only 4 (or 14%) focussing on other types of interventions, such as psychoeducational and biopsychosocial interventions.

Although only 29 RCTs were reviewed, the meta-analysis calculations were based on 36 comparisons, and the pooled standardised mean difference (SMD) was -0.31. This was equivalent to a pooled odds ratio of 0.57, representing a 43% reduction in the incidence of anxiety. Study authors also reported a statistically significant association between higher SMDs and the use of a wait-list control or a small sample size.

Conclusions

Based on these findings, psychological and/or educational interventions have a small yet statistically significant benefit for the prevention of anxiety in varied population types. Although the calculated effect size is modest when compared with the effect sizes observed in other treatments for anxiety disorders, it is in line with other meta-analyses focussing on the prevention of anxiety.

Importantly, study authors also concluded that the examined prevention programmes were effective regardless of the patient age group and, therefore, should be made available for individuals of all ages. Future studies should nonetheless strive to develop, test, and implement new anxiety prevention programmes which result in greater effect sizes.

Strengths and limitations

This is a well conducted meta-analysis with strict inclusion criteria, whereby only populations free of anxiety at baseline were allowed. This ensured that the study focussed only on prevention effectiveness rather than treatment effectiveness; an approach to applaud as we should be thinking of preventing mental illness whenever possible, instead of waiting until it is already too late to act.

This study also sought to evaluate the effectiveness of interventions targeting a range of ages, which is important, as studies often tend to focus only on adults. In addition, because most of the RCTs reviewed in this study were trialling interventions aimed at more than one type of anxiety disorder, it was not possible to make inferences about whether the interventions with highest effectiveness targeted specific types of anxiety disorders.

Other limitations included the small sample sizes of the included RCTs, with the majority of studies including less than 150 participants overall. Short follow-up periods were also a disadvantage, as only 8 of the 29 RCTs evaluated exceeded a 12-month follow-up period. This is particularly worrisome in the field of prevention, as it prohibits us to make firm conclusions about the long-term effectiveness of the interventions assessed.

Consequently, there is a need for more trials with larger sample sizes and longer follow-up periods, which will help us determine which anxiety prevention programmes are the most effective.

Implications for practice

This is an important study, which focussed on the prevention of anxiety disorders across the lifespan and concluded that the incidence of anxiety can be effectively reduced with the use of psychological and/or educational interventions. Moreover, as stated by Jenifer Hudson (2017) in the invited commentary:

although the effect is small, the importance of these findings at a population level should not be understated.

From a public health perspective, small effects on prevention can indeed result in high returns, leading to an overall better quality of life and a reduction in costs that would otherwise be spent on ‘late’ intervention.

In conclusion, although there is further work to be done in the development and implementation of these programmes, the prevention of anxiety can do little to no harm and is an effective way-forward for those at risk of anxiety disorders.

Conflicts of interest

No conflicts to declare.

Links

Primary paper

Moreno-Peral P, Conejo-Cerón S, Rubio-Valera M, Fernández A, Navas-Campaña D, Rodríguez-Morejón A, Motrico E, Rigabert A, Luna JDD, Martín-Pérez C, Rodríguez-Bayón A, Ballesta-Rodríguez MI, Luciano JV, Bellón JÁ. (2017) Effectiveness of Psychological and/or Educational Interventions in the Prevention of Anxiety. A Systematic Review, Meta-analysis, and Meta-regression (PDF). JAMA Psychiatry. 2017;74(10):1021–1029. doi:10.1001/jamapsychiatry.2017.2509

Other references

Craske MG, Stein MB, Eley TC. et al (2017). Anxiety disorders. Nature Reviews Disorders Primers, 3: 17024. [PubMed abstract].

Hudson JL (2017). Prevention of Anxiety Disorders Across the Lifespan. JAMA Psychiatry, 74(10): 1029-1030.

Kessler RC, Angermeyer M, Anthony JC. et al (2007). Lifetime prevalence and age-of-onset distributions of mental disorders in the World Health Organization’s World Mental Health Survey Initiative. World Psychiatry, 6: 168-176.

Wang PS, Angermeyer M, Borges G. et al (2007). Delay and failure in treatment seeking after first onset of mental disorders in the World Health Organization’s World Mental Health Survey Initiative. World Psychiatry, 6: 177-185.

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