The G2019S mutation in leucine-rich repeat kinase 2 (<i>LRRK2</i>) is a prevalent cause of late-onset Parkinson's disease, producing psychiatric and motor symptoms, including depression, that are indistinguishable from sporadic cases.
We identified one heterozygous G2019S mutation in a PD patient who also suffered from obsessive disorder and depression and presented hallucinations and delusional jealousy while he was treated with l-dopa, pramipexole, and amantadine.