Trishna Ghosh (Chettri, Bista)
Clinical Psychologist, Mental Hospital, Lagankhel, Patan, Nepal
Investigations have found the OCD indeed is associated with deficits in inhibition, impaired set shifting ability, poor working memory and low verbal frequency. However, till date, it has not been examined whether these deficits are trait-related (independent of symptomatology) or state-dependent (dependent of symptomatology). Since the data of this nature has an implication in the management of this condition, 51 OCD patient meeting the ICD-10 criteria for predominantly compulsive (F 42.1) formed the symptomatic group, and patients with file diagnosis of F 42.1 attending follow-up appointments and reporting 80% or more improvement currently with pharmacological, psychological or combination treatment formed the remitted group, were assessed by applying Wisconsin Card Sorting Test followed by Vancouver Obsessional Compulsive Inventory, State Trait Anxiety Inventory and Beck’s Depression Inventory. After ascertaining the normality distribution (Shapiro-Wilk test), Students “t” test was employed to determine the significance level between the symptomatic and remitted groups with respect to sociodemographic variables such as age, onset of illness, duration of illness and number of years of education. For rest of the variables Mann-Whitney “U” test was employed. The correlation analysis was carried out between the clinical and the neuropsychological measures using Spearman’s Rank difference method. Patients with OCD, both symptomatic and remitted, exhibit a lower level of performance in most measures of WCST as compared to patients with panic disorder and unspecified anxiety. Further, the present study indicated that the observed deficits in executive function are independent of symptomatology and unrelated to severity of the disorder. Though, the symptomatic group had more intensive symptoms than the remitted group, no significant relationship was evident between the symptoms and executive functions deficits in either of the groups. Though the remitted group made lesser number of perseverative errors and achieved more categories in comparison to symptomatic group, the differences were not significant. It suggest a trait hypothesis. The fact that the nature and severity of deficits on WCST in remitted group was similar to that was seen in symptomatic group; suggest the deficits in executive functions in OCD may be trait rather than state phenomena. Although, severity of obsessive-compulsive symptoms were found unrelated to performance, the anxiety and depression appeared to influence certain measures of executive functions in the current study.
The presence of trait anxiety reduced the occurrence of preservative error, also decreased the number of correct responses, in symptomatic group. Similarly, the set maintaining ability was negatively influenced by the depressive symptoms in symptomatic group and by the trait anxiety in remitted group.
These findings therefore suggest that abnormal WCST findings may not essentially indicative of specific
neuropsychological dysfunction in obsessive-compulsive disorder and poor performance may occur in the context of anxiety and depressive symptoms. Though, various forms of psychological/behavioral and pharmacological treatments are found to be effective in controlling the symptoms, they may be ineffective to correcting the underlying pathophysiology. For example, in the present study the performance on WCST barely improved in remitted group, though the treatment given included medication (29%), CBT (39%), and combination (32%). Thus it can be speculated, the persistence of the underlying pathophysiology may be responsible for the relapses and/or refractory nature of this disorder. In conclusion, the present study indicated that the deficits in executive functions are independently associated with both anxiety and depressive symptoms, but not with OC symptoms. Although these results need replication because of the limited number of subjects, they suggest the deficits in executive function, implying problem with the orbitofrontal cortex, may be trait-related in OCD than state-dependent.
Keywords: executive functions, symptomatic obsessive, compulsive disorder