Inhibition-related differences between tic-free and tic-related obsessive–compulsive disorder: evidence from the N2 and P3

A Review on P300 in Obsessive-Compulsive Disorder

“…Translationally, these are the patients who can benefit from a targeted cognitive-behavioral rehabilitation, associated with drug therapy. On the contrary, pediatric subjects, schizo-OCD patients, and severe OCD cases frequently show low-amplitude P300 ( 28 , 45 , 51 , 54 , 55 , 64 , 65 , 67 , 68 , 70 , 72 ), a finding in line with the brain imaging data reported by different authors ( 15 – 18 ). Based on the P300 parameters, follow-up studies after drug and rehabilitation therapy are warranted in order to gain further insights on the disease severity and the possibility of clinical and cognitive improvement ( 64 , 103 ).…”

“…Neuroimaging-based multimodal approaches have led to the conclusion that subtle brain structural changes and functional abnormality are present in OCD ( 15 , 17 , 18 ), with PET studies showing hypermetabolism in the orbital frontal cortex of these patients ( 85 , 97 ). In the context of structural changes in OCD, the value of a decreased amplitude of P300 becomes evident, as reported by several studies ( 28 , 45 , 51 , 54 , 55 , 64 – 68 , 70 , 72 ), similarly to those performed in schizophrenia ( 77 ). The finding of attenuated P300 amplitude has also been considered to be a pattern of genetic endophenotype in OCD ( 75 , 76 ), which has also been confirmed in pediatric studies ( 64 , 68 , 70 ).…”

“…A significant relationship between ERP abnormalities and severity of OCD symptoms was found in 13 studies ( 44 , 46 – 53 , 55 , 57 , 59 , 64 , 68 – 70 , 72 ). Thus, ERP abnormalities might be considered as a sensitive tool for measuring the biological substrate of OCD severity.…”

“…Overall, studies reporting a P300 amplitude reduction in OCD are thirteen ( 20 , 28 , 45 , 51 , 54 , 55 , 59 , 64 , 65 , 67 , 68 , 70 , 72 ), including the result of a P300 alteration at the F7 location in patients with functional constipation within a probable OCD ( 65 ). Conversely, we counted eight studies reporting enhanced P300 amplitude in OCD patients compared to normal controls ( 50 , 52 , 58 , 61 – 63 , 66 , 69 ), a finding that was considered as an electrophysiological correlate of an OCD trait and indicating an increased propensity to be aroused ( 50 , 77 ).…”

“…Furthrmore, the fact that several data have been published by the same research group needs be taken into account ( 64 , 67 , 68 , 70 ). However, it should be noted that most OCD individuals show a peculiar propensity to get aroused and typically exhibit strong defensive reactions even to minimal stimulation ( 19 , 20 , 42 – 46 , 48 , 50 , 55 , 71 , 72 ). Translationally, these are the patients who can benefit from a targeted cognitive-behavioral rehabilitation, associated with drug therapy.…”