Correlation Between Implicit And Explicit Memory Impairment And Obsessive-compulsive Symptoms In Patients With Obsessive-compulsive Disorder

Objective: Obsessive–compulsive disorder(OCD)is a kind of neurotic disorder characterized by repeated compulsive thinking and / or compulsive action.Symptoms of obsessive-compulsive disorder usually persist in a long-term fluctuating process,accompanied by great pain and disability.Two types of memory cognitive processing involve different neural mechanisms in patients with obsessive-compulsive disorder.Studies have shown that explicit memory processing in patients with obsessive-compulsive disorder is no different from that in healthy people.However,obsessive-compulsive disorder patients showed decreased implicit learning ability or abnormal increased program memory compared with healthy controls.Studies have also shown that people with obsessive-compulsive disorder do not have universal memory impairment.Clinical observation found that patients with obsessive-compulsive disorder(OCD)often showed repeated suspicion or worry about the completion of something,which suggested that obsessive-compulsive disorder patients could not recall their past experiences effectively.At present,there are different conclusions about implicit memory and explicit memory in patients with obsessive-compulsive disorder at home and abroad,and the correlation between implicit memory and explicit memory and obsessive-compulsive symptoms is less studied.Therefore,the task of speed test of vocabulary perception and the task of vocabulary recognition were used to further analyze the differences between implicit memory and explicit memory in patients with obsessive-compulsive disorder(OCD)and normal subjects,and the correlation between implicit memory and OCD symptoms.Methods: According to International Classification of Diseases and Related Health Problems,Tenth Revision(ICD-10),31 patients diagnosed with obsessive-compulsive disorder were included,and recruited 30 healthy people matched with gender,age and education level as normal controls.The accuracy and response time during vocabulary perception speed test tasks and vocabulary recognition tasks were recorded to index implicit memory and explicit memory performance.The obsessive-compulsive symptoms were assessed with Padovar scale-Washington State University revised edition(PI-WSUR)and Yale-Brown obsessive-compulsive scale(Y-BOCS).Results: There are significant difference two groups in the accuracy of implicit memory for moral disgust words(0.607±0.267 for OCD group,0.777±0.159 for controls group,t =-3.036,P =0.004),positive words(0.528±0.265 for OCD group,0.695±0.152 for controls group,t =-3.048,P =0.004)and all words(0.597±0.248 for OCD group,0.731±0.145 for controls group,t =-2.582,P =0.013).There are no significant difference two groups in the accuracy of implicit memory for neutral words(0.624±0.275 for OCD group,0.722±0.170 for controls group,t =-1.673,P=0.100).There are no significant difference two groups in the time reaction of implicit memory(2926.62±1718.31 for OCD group,2587.13±1054.56 for controls group,t=0.926,P =0.358).There are no significant difference two groups in the accuracy of explicit memory(0.72±0.09 for OCD group,0.69±0.08 for controls group,t =1.382,P=0.172).There are no significant difference two groups in the time reaction of explicit memory(946.49±194.80 for OCD group,884.93±146.45 for controls group,t =1.392,P =0.169).The response time of explicit memory in OCD group was significantly correlated with PI-WSUR(r =-0.410,P =0.022)and OTAHSO(r =-0.470,P =0.008).Conclusion: Compared with healthy controls,the implicit memory of OCD patients was impaired,especially the implicit memory of positive emotion words and moral disgust words.There is no correlation between implicit memory and obsessive-compulsive symptoms in OCD patients.Compared with healthy controls,the implicit memory of OCD patients is not impaired,but there is a correlation between explicit memory and obsessive-compulsive symptoms in OCD patients..