Psychiatric symptoms in Parkinson's disease: A comparison between patients with and without “on-off” symptoms

Abstract

Approximately 50% of patients with Parkinson's disease (PD) who receive long-term levodopa therapy develop clinically significant motor fluctuations (Marsden and Parkes 1976). These fluctuations occur throughout the day and may include abrupt and dramatic swings from immobility to choreoathetosis (onoff' phenomena). Accompanying these motor fluctuations in many patients are phasic mood changes that parallel the motor changes. These changes in mood occur in the majority of patients and are generally characterized by depression and anxiety in the immobile off period, with improvement or even euphoria during the and dyskinetic periods (Hardie et al 1984: Menza et al 1990; Giriotti et al 1986; Nissenbaum et al 1987; Cantello et al 1986: Friedenburg and Cummings 1989~ Brown et al 1984). in rare patients, these mood swings may be so severe as to include hallucinations, delusions, and mania (Hardie et al 1984; Nissenbaum et al 1987; Keshavan et al 1986). Explanations of the motor fluctuations have centered on the changes in the functional activity of dopamine (DA) in the striaturn. Underactivity produces rigidity and immobility, whereas excess dopaminergic stimulation produces dyskinesias. This variation in activity may result from fluctuations in plasma levodopa levels (Hardie et al 1984), alterations in dopaminergic receptor sensitivities (Klawans et al 1977; Dougan et al 1978), or involvement of other: neurotransmitter systems (Marsden and Park~.s 1981; Teyehenne et al 1982). Similarly, speculation over the cause of the parallel mood changes that accompany on-off motor fluctuations has involved both central dopaminergic changes and psychological reactions to fluctuating motor impairment and disability (Menza et al 1990; Giriotti et al 1986; Nissenbaum et al 1987; Cantello et al 1986). Although these mood changes are known to accompany motor changes in many individuals, there are no data on the psychiatric status of on-off patients as a group, evaluated during '~on periods, compared with patients with PD without on-off phe-