The relation of depression and anxiety to homocysteine and clinical features of Parkinson’s disease

Objective: In this study, we aimed to find out whether depressive and anxiety symptoms were influenced by homocysteine (Hcy) and whether depressive and anxiety symptoms in IPD were associated with age, disease duration, age of disease onset, stage, the Unified Parkinson Disease Rating Scale (UPDRS), and to assess the impact of drugs used in parkinsonism on Hamilton depression (HAMD) and anxiety (HAMA) rating scales in IPD.

Methods: Forty patients with IPD (27 male, 13 female) and twenty-one healthy subjects (6 male, 15 female) who attended our movement disorders outpatient clinics were included in this study. The diagnosis of PD was confirmed by a movement disorders specialists in Neurology, according to UK Parkinson’s Disease Society Brain Bank Criteria. The HAM-D and HAM-A rating scales were administered toParkinson patients and healthy subjects. Anti-parkinsonian treatments were recorded and the total daily dose of levodopa was calculated for each patient. Homocysteine levels were measured in Parkinson’s patients and in healthy subjects.

Results: Rates of 92.5% (n=37) severe depression and 62.5% (n=25) mild anxiety were found in Parkinson’s patients. There was no difference between Parkinson’s patients and the control group in depression (p=0.78). There was higher mild anxiety in Parkinson’s patients than in the control group (p=0.05). There was no correlation between Homocysteine level and HAM-A-HAM-D (r=0.009 p=0.95 r=0.24 p=0.12, respectively). However, there was a positive correlation between HAM-D and UPDRS total, UPDRS motor sections, UPDRS activities of daily living (r=0.45 p=0.006 r=0.38 p=0.002 r= 0.47 p=0.004, respectively). Also there was a positive correlation between HAMA and UPDRS total, UPDRS activities of daily living, UPDRS cognitive, UPDRS complication of treatment (r=0.41 p=0.01 r=0.51 p=0.001 r=0.38 p=0.02 r=0.32 r=0.05, respectively). The subgroups of drugs (levodopa+ dopa decarboxylase enzyme inhibitor (DDEI), levodopa+DDEI+entacapone, and other drugs) were compared to each other; equivalent dose and significant difference were found in terms of mean levodopa dosage (p=0.007). The Levodopa+DDEI subgroup had a higher mean levodopa dosage than levodopa+DDEI+entacapone and other drug subgroups. Although statistically insignificant, there were higher levels of hcy, HAM-A and HAM-D in the L-Dopa+DDEI subgroup.

Conclusion: In our study, comparing Parkinson patients and the normal control group, we found no significant relationship between depression scores but significantly higher scores of mild anxiety in Parkinson’s patients compared to the control group. There were no correlations between Hcy levels and HAM-A and HAM-D scores. Although statistically insignificant, when equivalent dosage estimation was done, HAM-A and HAM-D scores were higher in the group having the highest mean levodopa dosage. Thus this subject needs to be evaluated in another study with a large number of patients.