J021 Antidepressant prescribing patterns in Huntington’s disease: regional and case-control differences

<h3>Background</h3> Antidepressants are frequently used for a number of common psychiatric disorders in Huntington’s disease (HD), but evidence of efficacy is lacking. Drug availability differs across continental regions (Europe, North America, South America, Australasia), making it difficult to compare differences in antidepressant choice between HD patients and controls. <h3>Aims</h3> Determine differences in antidepressant choice for common psychiatric symptoms between cases and controls, accounting for regional differences in prescribing patterns. <h3>Methods</h3> Using data from ENROLL-HD, we categorised the indication for antidepressant prescription into common psychiatric symptoms. Using multinomial modelling we compared the frequency of use of common antidepressant classes between cases and controls, accounting for differences across ENROLL-HD regions. <h3>Results</h3> Anxiety and depression accounted for the majority of indications for antidepressant use in HD. Irritability necessitating antidepressant treatment was very infrequent in controls, but common in HD. As expected, a number of regional differences in antidepressant use were found. Accounting for regional differences, Mirtazapine was more frequently used in HD patients compared to controls for both depression and anxiety, whilst SNRIs and drugs with a unique mechanism of action were less frequently used in HD patients with depression, compared to controls. Within regions, prescribing patterns differed between HD and controls, but without any consistent pattern. <h3>Conclusions</h3> Antidepressants prescription patterns differ between HD patients and control subjects both across and within regions, without evidence to support this practice. This highlights the need for clinical trials of antidepressants in HD