Objectives Dopamine-dysregulation syndrome (DDS) is an uncommon complication of the treatment of Parkinson’s disease, characterised by addictive behaviour and excessive use of dopamine medication. Patients may develop prominent dyskinesias, cyclothymia, psychosis and significant functional decline. There is an increasing recognition of neuropsychiatric symptoms in Parkinson’s disease, however, it is likely that DDS frequently goes unrecognised or misdiagnosed. We aim to clarify current understanding of clinical characteristics, risk factors and management of DDS to increase the recognition of this disorder.
Methods Cases were identified through a search of online databases (PUBMED, EMBASE, google scholar) and a secondary search of references of identified articles. Search terms were dopaminergic dysregulation syndrome, hedonistic homeostatic dysregulation, dopamine/levodopa addiction. Cases were included if they met criteria for DDS. Case-cohort studies were also reviewed and will be discussed further.
Results We reviewed 390 articles and identified a total of 98 cases of DDS. There was a predominance of male cases (83%), with an early age of onset of Parkinson’s (mean average 46 years), and a mean average duration of illness of 11 years. Past substance and psychiatric history was present in 15 and 10 cases. Co-morbid impulse control disorders were present in 61% of cases and punding in 21%. There was a large variety of management strategies utilised, with only 56% of cases documented as resolving after treatment, most of these reliant on strict caregiver supervision. Of note sodium valproate was used successfully in 5 cases. The response to deep brain stimulation was varied.
Conclusions In general, DDS cases represent a diverse cohort of individuals that do not necessarily have the previously identified risk factors of past psychiatric history and substance use. Treatment of DDS is complex and may be more successful when family and caregivers are on side. Prognosis appears to be improved with early diagnosis and treatment. It is recommended that screening for DDS is considered in at risk populations. Further research is needed to clarify the true prevalence of this condition, and to identify possible preventative strategies.