PEARLS 24, October 2007, written by Brian R McAvoy
(First published New Zealand Doctor, 7 November 2007)

Clinical question
How effective are psychological therapies, such as cognitive behavioural therapy (CBT),sychodynamic therapy and supportive therapy, compared with treatment as usual/waiting list (TAU/WL) and compared to one another, for patients with generalised anxiety disorder (GAD)?

Bottom line
Psychological therapy based on CBT principles is effective in reducing anxiety symptoms and secondary symptoms of worry and depression for short term treatment of GAD (NNT* 3 or 4 compared with usual care). It is not clear whether patients attending CBT sessions are more likely to have reduced anxiety at the end of treatment than patients attending psychodynamic therapy or supportive therapy. (* NNT = number needed to treat to benefit one individual)

Caveat
People who attend group CBT and older people are more likely to drop out of therapy. Studies lasted from 4 weeks to 24 months with an overall mean duration of 8 months. The intensity of treatments ranged from 4 to 16 sessions, lasting from 45 minutes to 2 hours. None of the studies looked at the long term effectiveness of CBT, or reported on the possible side effects or acceptability of psychological therapies.

Context
GAD is a common disorder, characterised by excessive worry or anxiety about everyday events and problems. It is estimated to have a lifetime prevalence of 5.1 per cent with a 12 month prevalence measurement of 3.1 per cent.1

Cochrane Systematic Review
Hunot V, Churchill R, Teixeira V, Silva de Lima M. Psychological therapies for generalised anxiety disorder. Cochrane Database of Systematic Reviews 2007, Issue 1. Article No. CD001848. DOI: 10.1002/14651858.CD001848.pub4.
Note: This review contains 25 studies with 1305 participants.

Further reference
1. Kessler RC et al. Arch Gen Psychiatry 1994;51:8-19.