Personality and Alexithymic Disparity in Obsessive-Compulsive Disorder Based on Washing and Checking

The aim of this study was to investigate pathway relationship of personality characteristics and alexithymic traits in OCD symptoms of obsession, and compulsive behavior of washing and checking. Two-hundred and seventy patients diagnosed with OCD were consecutively recruited from the psychiatric outpatient department of a teaching hospital. Structural equation modeling showed those more neurotic, less extraverted and with higher levels of alexithymia difficulty identifying feelings (DIF), difficulty describing feelings (DDF) and externally oriented thinking (EOT) were more likely to develop obsessive thoughts. Those less extraverted was more prone to develop washing compulsions, and those more neurotic were more likely to develop checking compulsions. EOT was the only alexithymic trait to have no gender difference within this group of patients with OCDs. The different personality and alexithymic trait pathways found between OCD obsession, washing and checking symptoms provide support that they may be different subtypes within the OCD diagnosis. Obsession was associated with washing, but not checking. Furthermore, no gender difference was found between the obsession and compulsive symptoms. Extraversion and neuroticism can be used to differentiate washing and checking, and alexithymia to differentiate washing and obsessions. This should be taken into consideration for intervention targeting patients with different OCD symptoms.

Electrophysiology of facilitation priming in obsessive-compulsive and panic disorders

OBJECTIVE

Repeated experience with stimuli often primes faster, more efficient neuronal and behavioural responses. Exaggerated repetition priming effects have previously been reported in obsessive-compulsive disorder (OCD), however little is known of their underlying neurobiology or disorder-specificity, hence we investigated these factors.

METHODS

We examined event-related potentials (ERPs) and behaviour while participants with OCD, panic disorder and healthy controls (20 per group) performed a Go/NoGo task which manipulated target repetition sequences.

RESULTS

Both clinical groups showed stronger reaction time (RT) priming than HCs, which in OCD was greater in a checking, than washing, subgroup. Both clinical groups had similar RT deficits and ERP anomalies across several components, which correlated with psychopathology and RT priming. In OCD alone, N1 latency tended to increase to repeated stimuli, correlated with O-C symptoms, whereas it decreased in other groups. OCD-checkers had smaller target P2 amplitude than all other groups.

CONCLUSIONS

Enhanced neural priming is not unique to OCD and may contribute to salient sensory-cognitive experiences in anxiety generally. These effects are related to symptom severity and occur to neutral stimuli and in the context of overall RT impairment, suggesting they may be clinically relevant and pervasive. The results indicate overlapping information-processing and neurobiological factors across disorders, with indications of OCD-specific trends and subgroup differences.

SIGNIFICANCE

This first electrophysiological investigation of OCD priming in OCD to include anxious controls and OCD subgroups allows for differentiation between overlapping and OCD-specific phenomena, to advance neurobiological models of OCD.

Neuropsychological differences between obsessive-compulsive washers and checkers: a systematic review and meta-analysis

Inconsistent results in neuropsychological research of obsessive-compulsive disorder (OCD) may be the result of the heterogeneous nature of OCD symptoms. The most frequently investigated symptoms are contamination/cleaning and doubt/checking. The aim of this review was to determine whether OCD washers and checkers differ in their neuropsychological performance. We conducted a meta-analysis of 13 studies (including 535 patients) comprising tests in 10 different neuropsychological domains. Washers showed significant better task performance than checkers in 8 of 10 cognitive domains. Large effect sizes were found in planning/problem solving and response inhibition. Effect size in set shifting was medium, whereas effect sizes in attention, processing speed, encoding, verbal memory and nonverbal memory were small. Limitations consisted in a relatively small number of primary studies. In line with current neurobiological findings, the results provide further evidence for the validity of different symptom dimensions in OCD. Clinical and theoretical implications are discussed.