Function In Obsessive-compulsive Disorder Research Articles

Serotonergic Function in Obsessive-Compulsive Disorder

To evaluate serotonergic (5-hydroxytryptamine) function in obsessive-compulsive disorder, behavioral and neuroendocrine responses to m-chlorophenylpiperazine (m-CPP; 0.5 mg/kg orally) and fenfluramine hydrochloride (60 mg orally) were examined in 20 patients and 10 healthy controls under double-blind, placebo-controlled conditions. Following m-CPP, but not fenfluramine or placebo, 55% (11/20) of the patients with obsessive-compulsive disorder experienced a transient exacerbation of obsessive-compulsive disorder. Prolactin response was blunted in patients following m-CPP but not following fenfluramine. Patients with greater behavioral response to m-CPP had smaller prolactin responses. Cortisol response to m-CPP and fenfluramine did not significantly differ between the groups. Behavioral and neuroendocrine responses appeared divergent. This does not suggest simply upregulation or downregulation of 5-hydroxytryptamine receptors, but rather complex mechanisms involving multiple neurotransmitter and neuromodulator systems.

Neuropyschological performance in obsessive-compulsive disorder

Neuropsychological functioning was examined in a group of 18 nondepressed patients with obsessive-compulsive disorder (OCD) and 18 age-, education-, and gender-matched normal controls. A recent nonverbal memory deficit was identified in the patients with OCD. From performance on timed and untimed measures of the same constructs, it appears that OCD patients score more poorly than controls when speed is a factor. Although performance on a timed tactual-spatial motor test was also impaired, it is unclear whether this deficit is attributable to the nonverbal memory and/or speed deficits. Deficits in verbal abilities, including recent verbal memory, were not identified. Results were equivocal for executive function and visual-spatial abilities. The previously established association of recent nonverbal memory abilities with functioning of the right mestal temporal area is discussed in the context of current hypotheses about the neuroanatomic substrate of OCD.

Noradrenergic function in obsessive-compulsive disorder: Behavioral and neuroendocrine responses to clonidine and comparison to healthy controls

To evaluate noradrenergic (NE) function in obsessive-compulsive disorder (OCD), behavioral, phychological, and neuroendocrine responses to the α 2-adrenergic agonist clonidine were examined in 18 patients with OCD and 10 healthy subjects. Subjects received single i.v. doses of 2μg/kg of clonidine administered under double-blind, placebo-controlled, random-assignment conditions. Following clonidine, but not following placebo, patients transiently experienced a significant reduction of obsessions and compulsions. Significant drowsiness and a reduction in anxiety were also noted, but the antiobsessional effect appeard independent of the soporific and antianxiety effects. Growth hormone (GH), cortisol, and 3-methoxy-4-hydroxyphenylglycol responses to clonidine did not differentiate patients from healthy controls. Blood pressure and pulse in response to clonidine did not differ between groups. Improvement in OCD symptoms after clonidine significantly correlated with GH response to clonidine, suggesting specific noradrenergic mediation. This finding lends only partial support for a primary defect of noradrenergic function in OCD.

Endogenous event-related potentials in obsessive-compulsive disorder

Brain event-related potentials (ERPs) were used to investigate central nervous system (CNS) correlates of cognitive function in obsessive-compulsive disorder (OCD). ERPs of 10 unmedicated OCD patients and 10 normal controls were measured in an auditory “oddball” task. Increasing task difficulty resulted in longer N200 and P300 latencies in normal subjects, but not in OCD patients. Moreover, OCD patients displayed shorter P300 latency than normal controls for the more difficult discrimination condition. This replicates prior findings of Beech et al. (1983) for a visual task. For both levels of task difficulty, OCD patients also showed greater negativity than normal controls in the N200 region, which extended into the subsequent slow wave region. Negativities in the N200 and slow wave regions were larger at sites over the left hemisphere than the right hemisphere. The enhanced negativities and reduced P300 latency in OCD patients are discussed in terms of current theories postulating cortical hyperarousal and left hemisphere involvement in OCD.

Humoral Immune Function in Obsessive Compulsive Disorder

Humoral Immune Function in Obsessive Compulsive Disorder

Serotonin Function in Obsessive-Compulsive Disorder

To evaluate the role of serotonin (5-HT) function in obsessive-compulsive disorder (OCD), behavioral and biochemical responses to the 5-HT receptor agonist m-chlorophenylpiperazine (MCPP) and the 5-HT precursor tryptophan were examined in healthy subjects and patients with OCD. Baseline prolactin levels and the prolactin rise following MCPP were significantly reduced in female patients compared with female healthy subjects. In contrast, the increase in prolactin level following tryptophan administration was not significantly different between male or female patients with OCD and the respective sex-matched healthy subjects. The prolactin responses to MCPP and tryptophan were both significantly higher in female patients and healthy subjects than in their male counterparts. The cortisol and growth hormone responses to MCPP and tryptophan were similar in the patients and healthy subjects and were not related to gender. The behavioral responses to MCPP or tryptophan were not consistently different between patients and healthy subjects, and neither MCPP nor tryptophan had effects on obsessive or compulsive symptoms. These results lend only partial support to the hypothesis that 5-HT dysfunction may be linked to the pathophysiology of OCD and point to the need for the evaluation of other neurotransmitter systems in future investigations of OCD.