Clinical efficacy of deep brain stimulation for psychiatric and neurological indications on a meta-analytic level

Deep brain stimulation (DBS) is used to treat movement disorders, but it is rarely used for psychiatric indications. We aim to demonstrate clinical effects in randomised-controlled trials (RCTs) of DBS for clinically used neurological and psychiatric indications.

We searched databases for RCTs conducting blinded comparisons of active to sham DBS for: obsessive-compulsive disorder (OCD), major depressive disorder (MDD), Gilles-de-la-Tourette syndrome (GTS), Parkinson's Disease (PD), essential tremor (ET), dystonia (DYT) and epilepsy (ED). We compared 28 studies with a meta-analytic approach of the indication-specific scores.

For psychiatric indications, we found a standardised mean difference (SMD) of -0.22 for MDD (p = .204), a SMD of -0.72 for OCD (p = .004) and a SMD of -1.22 for GTS (p = .014). For neurological indications, we found a SMD of 0.74 in PD (p < .001), a SMD of -1.42 in ET (p = .0003), a SMD of -0.71 for DYT (p = .006) and a SMD of -0.09 for ED (p = .790).

Effect sizes in clinical trials were highest in ET in neurology and in GTS in psychiatry. These results underscore that wider clinical use in the psychiatric indications OCD and GTS is justifiable.