Alexithymia has been found to be strongly associated with depression in both general and clinical populations. Alexithymic and depressive symptoms may be partially overlapping, but not all are correlated with depressive symptoms, thus underlining the relative independence of the two disorders. Parkinson's disease (PD) is a clinical condition often characterized by depression and an altered emotional processing. In medicated PD patients alexithymia has a prevalence of 21% and is related to depression.
The investigation of alexithymia in newly diagnosed untreated (de novo) PD patients before the administration of dopaminergic therapy is of particular clinical interest considering that affective symptoms may precede the clinical motor onset of PD. This study was aimed at investigating the prevalence of alexithymia in de novo PD patients and its relation to depression. To estimate the prevalence of alexithymia and its relation to depression in de novo PD patients the Twenty-Item Toronto Alexithymia Scale (TAS-20) and the Geriatric Depression Scale Short Form (GDS-15) to 42 de novo PD patients and 30 age-matched healthy controls (HC) were administered.
The de novo PD patients were enrolled in two Italian movement disorder tertiary clinics (Versilia Hospital, Viareggio; Neurological Clinic, University of Pisa). The severity of motor symptoms was measured by the Unified Parkinson's Disease Rating Scale (UPDRS II and III). In all enrolled subjects the global cognitive status was assessed with the Mini-Mental State Examination (MMSE). The TAS-20 total score allowed categorizing subjects as nonalexithymic (scores ranging from 20 to 51), borderline alexithymic (scores ranging from 52 to 60), or alexithymic (scores ≥ 61). No differences were found for age, education, cognitive status (MMSE), alexithymia (TAS-20 score) and depression (GDS-15 score) between de novo PD patients and HC. A statistically significant difference was approached for the TAS-20 subscale F2 (p = 0.07). In the group of de novo PD patients, cutoff scores of the TAS-20 identified 10 alexithymic patients (23.80%), 11 borderline alexithymic patients (26.19%) and 21 nonalexithymic patients (50.01%).