<p>We present here a clinical case of a teenage patient illustrating the difficulties of diagnosis and treatment of mental pathology at the onset of juvenile parkinsonism developing as a result of compound heterozygous mutations and proceeding with moderate akinetic-rigid and pseudopyramidal syndromes and combined tremor. Before the onset of distinct symptoms of parkinsonism and the genetic study confirming the diagnosis, the patient had been observed for several years with a variety of psychiatric diagnoses and had received psychotropic therapy. This case demonstrates the difficulties of the differential diagnosis of juvenile parkinsonism in children at the early stages due to multiple comorbid motor, affective, and behavioral disorders. A multidisciplinary approach is required when neurological symptoms appear in patients, and this must include joint diagnostic investigations by psychiatrists and neurologists to establish an accurate diagnosis and select the optimal therapy. Implementation of the principles of interdisciplinary interaction in the management of such patients will improve the promptness of diagnosis and the delivery of pathogenetically based therapy.</p>