GPs can be reassured that antidepressants work for treating generalised anxiety disorder according to an updated Cochrane review that found ‘high confidence’ in their effectiveness in the short term.
But more research is needed to unpick the long-term implications of taking the drugs for anxiety, the Canadian team concluded.
UK experts warned that long-term treatment is often the norm but there is increasing concern that patients may have difficulty stopping taking antidepressants due to withdrawal symptoms.
Antidepressants, particularly selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs), are recognised treatments generalised anxiety disorder including by NICE, the Cochrane reviewers said.
But misconceptions remain among some healthcare professionals and patients who do not realise that ‘antidepressants’ have wider indications beyond depression.
There can also be stigma attached to their use, they added.
An update was needed because more studies have been done in recent years on efficacy, acceptability, tolerability, and impact on the quality of life of the various types of antidepressants compared to placebo, they explained.
The team looked at data from 37 randomised controlled trials with over 12,000 participants, with slightly more female participants (around 60%) which they reported was reflective of the clinical prevalence of generalised anxiety disorder seen in the real world.
Overall antidepressants were more effective than placebo in reducing anxiety symptoms, with a 41% higher response rate among those taking the medication compared to those taking a placebo.
There was also no significant difference in dropout rates between those taking antidepressants and those taking a placebo, indicating that these medications are generally well-tolerated.
But most included trials only lasted between 4 to 12 weeks, with no long-term follow-up.
Senior author Dr Giuseppe Guaiana, associate professor of psychiatry at the Schulich School of Medicine & Dentistry, Western University, Canada, said this research showed that antidepressants were ‘highly effective’ at treating generalised anxiety disorder ‘at least in the specific circumstances seen in trials’.
‘For people with generalized anxiety disorder and no other conditions, we have good evidence that antidepressants lead to clinically meaningful improvements over a one- to three-month period compared to placebo.’
But there was not enough evidence to assess their effectiveness when used for anxiety alongside other mental health conditions, which is much more common in clinical practice, he added
‘Most of the patients I see with [generalised anxiety disorder] also have other mental health conditions, so future trials should investigate the effects of different treatment strategies on patients with multiple conditions.’
Co-author Katarina Kopcalic, also from Western University, added: ‘We don’t have enough information on the potential long-term benefits and harms of antidepressants, even though people often take them for years.
‘This is an area that needs further exploration in future trials.”
Professor Peter Tyrer, professor of community psychiatry at Imperial College London, said: ‘The findings of this review are unequivocal – antidepressants are effective in the treatment of generalised anxiety in the short-term.’
But the long-term implications also have to be considered, he added.
‘Long-term treatment, as noted in the review, is often the norm, and there is increasing concern that patients have difficulties in stopping antidepressants because of withdrawal problems.
‘Bearing in mind that the main reason why antidepressants were preferred to benzodiazepines (drugs that are equally effective in treating generalised anxiety) was the dependence risk, we just seem to have shifted the problem of adverse effects from one class of drugs to another.’
