Neuropsychiatric symptoms in Serbian patients with Parkinson's disease Mirjana Petrovic a , Elka Stefanova b,c , Ljubomir Ziropadja d , Tanja Stojkovic b,c , Vladimir S. Kostic b,c, ⁎ a Clinic of Neurology, Clinical Center Kragujevac, Serbia b Faculty of Medicine, University of Belgrade, Serbia c Clinic of Neurology, CCS, Serbia d Faculty of Philology, University of Belgrade, Serbia abstract article info Article history: Received 14 January 2016 Received in revised form 12 May 2016 Accepted 10 June 2016 Available online 13 June 2016 Background: Parkinson's disease [PD] is associated with wide variety of neuropsychiatric symptoms, although it is primarily considered as a movement disorder. Objective: To examine whether PD patients can be meaningfully classified into subgroups according to their neu- ropsychiatric symptoms, reported by their caregivers. Methods: Three hundred and sixty PD patients [mean age = 63.5, SD = 10.3] from the academic clinical setting were assessed with the 12-subscale Neuropsychiatric Inventory Questionnaire [NPI]. A two-stage cluster analysis was used to identify the subgroups groups of patients with specific neuropsychiatric profile. Results: Three hundred and twenty-one PD patients [89%] showed at least one psychiatric symptom. The most common symptoms were anxiety [73.1%], depression [64.7%], and apathy [51.7%], and nighttime disturbance [51.3%], whereas the least common were euphoria [0.3%], and delusions [1.7%]. The mean [SD] total NPI compos- ite score was 16.9 [17.4]. Two hundred eight PD subjects [58%] of the total sample had at least one symptom with a score ≥ 4. Three clusters were identified: a] Cluster 1, with no or few NPI symptoms [n = 200; 55.6%]; b] Cluster 2, with mild to moderate symptoms on depression, anxiety and apathy scales [n = 140; 38.9%]; and c] Cluster 3 with high agitation, disinhibition and irritability scores [n = 20 patients; 5.6%]. PD subjects with clinically signif- icant neuropsychiatric symptoms were older with more severe motor and cognitive impairment. Conclusions: This study emphasizes the high prevalence and importance of neuropsychiatric symptoms in PD pa- tients; therefore clinicians should also focus on treating in parallel with motor symptoms. © 2016 Elsevier B.V. All rights reserved. Keywords: Neuropsychiatric inventory Caregiver Cluster analysis 1. Introduction Prevalence of neuropsychiatric co-morbidities in Parkinson's disease [PD] varies widely among reported series due to increasing age of pa- tients, duration of the disease, cognitive impairment and assessment tools [1–6]. Also, cultural, social and family structure might be responsi- ble for differences [7–12]. Growing evidence indicated existence of PD subtypes based on asso- ciated neuropsychiatric and behavioral problems [5,6,13], either in the cohorts of the early stage “de novo” PD patients [14], or in those with dementia [13]. Neuropsychiatric symptoms (NPS) are part of the non- motor manifestation of PD, and have a significant impact on the quality of life [QoL] of PD patients, and on a caregiver burden and distress [pres- ence of NPS apart from dementia is associated with caregiver distress] [8,15,16,17]. Therefore, in the present study we administered the Neuropsychiat- ric Inventory [NPI] [18], to evaluate the frequency of neuropsychiatric symptoms and accompanied caregiver distress in a representative sam- ple of Serbian patients with PD, recruited at the academic tertiary clini- cal center. The NPI uses a screening strategy to minimize administration time, examining and scoring only those behavioral domains with posi- tive responses to screening questions. Both the frequency and the sever- ity of each behavior are determined. Information for the NPI is obtained from a caregiver familiar with the patient's behavior [18]. We expected Journal of the Neurological Sciences 367 (2016) 342–346 ⁎ Corresponding author at: Institute of Neurology, CCS, Dr Subotica 6, 11000 Belgrade, Serbia. E-mail address: vladimir.s.kostic@gmail.com (V.S. Kostic). http://dx.doi.org/10.1016/j.jns.2016.06.027 0022-510X/© 2016 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Journal of the Neurological Sciences journal homepage: www.elsevier.com/locate/jns