Relationship between antidepressant and anxiolytic/hypnotic prescribing: a mixed-methods study.

BACKGROUND

Antidepressant prescribing has dramatically increased in Scotland, and the cause is unknown.

OBJECTIVE

To investigate if the increase in antidepressant prescribing coincided with a reduction in prescribing of anxiolytics and hypnotics; to investigate this relationship at practice level; and to explore whether general practitioners (GPs) explain the increase by their increased use for anxiety.

STUDY

DESIGN

analysis of routine prescribing data and interviews with GPs.

SETTING

Scottish general practices.

PARTICIPANTS

942 practices included in the analysis. Sixty-three GPs in 30 practices completed interviews.

MAIN OUTCOME MEASURES: Quantity of antidepressants, anxiolytics, and hypnotics prescribed. Relationship at practice level between anxiolytic/hypnotic and antidepressant prescribing. Spontaneous comments by GPs about prescribing antidepressants for anxiety.

RESULTS

Antidepressant prescribing increased from 28.9 million defined daily doses (DDDs) in 1992/3 to 128.3 million in 2004/5. Anxiolytic/hypnotic prescribing fell from 64.2 million to 55.1 million DDDs. There was a weak, positive correlation between levels of antidepressant and anxiolytic/hypnotic prescribing (+0.084, p=0.010). GPs treated anxiety with antidepressants, although many described an overlap between anxiety and depression. Some spontaneously identified a relationship with benzodiazepine prescribing when asked to explain the increase in antidepressant prescribing.

CONCLUSION

A small part of the increase in antidepressant prescribing is due to substitution for benzodiazepines to treat anxiety.