OCD
Neuropsychological perfomance
Motor deficits
Fine motor control deficits (Grisham et al., 2009)
Bloch et al. (2011) speculated that the reduced ability of motor control is present before the explicit manifestation of OCD and is instead a part of the cause of its pathology.
Identifying differences in motor control performance across different OCD subtypes would be crucial in understanding how OCD types differentially develop
Rationale
Memory
Nedeljkovic et al. (2009)- Spatial Recognition deficits in Obsessing Subtype
Nedeljkovic et al. (2009)- Spatial working memory deficits in 'Checking Subtype'
Neurological differences
Ravindran et al., 2020 - Exploratory analyses suggested that stimulus-provoked activity and connectivity was elevated for checking subtypes in motor cortices and elevated in washing subtypes in the anterior insula and orbitofrontal cortex.
Purcell et al. (1998) reported poorer spatial memory and spatial working memory (SWM) and slowed motor responses in an OCD cohort compared to NCs, and to cohorts with either panic disorder or major depression. memory performance worse than other mental illnesses??
Borges et al., 2011 - Impaired Verbal and Visuospatial memories. Correlation between OCD Severity and amount of deficit.
Executive Function
Borges et al., 2011 - Impaired Set-shifting (unconscious shifting of attention - executive function). Correlation between OCD Severity and amount of deficit.
Nakao et al., 2009 - Could not find any correlation between the neuropsychological scores and Y-BOCS score
Mataix-Cols et al. (1999) found that poorer performance on a planning task positively correlated with score on the checking scale of the PI in a subclinical OCD cohort.
However, this approach has not revealed replicable results.
Cottraux, Gerard, Cinotti, & Froment (1996) found that OCD patients with primarily checking rituals evidenced greater orbitofrontal and temporal lobe activity, and lesser basal ganglia activity, relative to nonpatient controls when the urge to check was evoked.
Kessing (2007) - there are different subtypes of depression that have neurological differences
In various Neuroimaging studies, it has been found that participants with OCD have larger putamen, and pallidum/globus pallidus volumes - both areas of the Basal ganglia (an area heavily implicated in the inhibition or excitation of certain brain signals, particularly movement signals).
in the basal ganglia, in OCD the Caudate nucleus is dysfunctional, causing signals from the orbitofrontal cortex (OFC) to not be suppressed - leading to an over-excitation of the thalamus, which then sends strong signal back to the OFC - leading to an unceasing loop of intense anxiety.
CITE?
CITE?
At the same time there are reductions in frontal cortex areas, including, but likely not limited to, the VMPFC, DMPFC, IFC, and the OFC. The frontal cortex is heavily implicated in attentional control and suppressing certain thoughts and emotions. If this area is dysfunctional it could lead to thoughts being perpetuated as well as dysfunction in other task behaviours, such as motor tasks.
CITE?
Reduced Temporal Lobe Volume (linked to worsened memory and spatial processing?). And hippocampus
(Inferior) Parietal [cortex] lobe dysfunction - de Wit et al., 2011
Motor Control
Motor inhibitory control - Stop-signal task (Logan & Cowan, 1984)
Boulton, 2020 - Emily (33, Heterosexual, White British) reported dealing with her genital response through clenching her pelvic floor muscles: ‘Due to contamination OCD I would not sit down on toilets properly, and due to paedophile obsessions I would clench my pelvic floor muscles to prevent any perceived arousal. As a result of both of these compulsions, I now have over tense pelvic floor muscles which creates sexual problems (pain etc).’
Women who reported talking about sex with their therapist stated that they experienced judgements about their sexuality, sexist advice and well meant, but ultimately unhelpful, therapeutic interventions.
Boulton, E. 'One dead bedroom': Exploring the impact of Obsessive-Compulsive Disorder (OCD) on women's lived experience of sex and sexuality. (Thesis). University of the West of England. Retrieved from https://uwe-repository.worktribe.com/output/1906784
Symptoms
Groinal Response
Obsessions
Compulsions
Groinal response in certain OCDs - Bruce, Ching, & Williams, 2018, p.396
Subtypes
Obsessional
SO-OCD (Sexual Orientation OCD)
R-OCD - focus on their relationships, for example, repeatedly doubting their feelings for their partner and their partner’s feelings for them (see Doron, Derby, Szepsenwol, & Talmor, 2012; Doron, Mizrahi, Szepsenwol, & Derby, 2014)
Scrupulosity / R-OCD
P-OCD - involves “excessive worries and distressing intrusive thoughts about being sexually attracted to, and sexually violating, children” (Bruce, Ching, & Williams, 2018, p.389; see also Vella-Zarb, Cohen, McCabe, & Rowa, 2017)
HOCD (/ Homosexual OCD) - Focuses on fears around the alteration of sexual-orientation, of being perceived as gay or of having supressed same-sex desires (Williams, 2008; Williams, Crozier, & Powers, 2011; Williams & Farris, 2011)
OCD is estimated to affect 2–3% of the world’s population (Monteiro & Feng, 2016)
TOCD / Transgender OCD - Safer et al., 2016
Washing
Checking
Neutralising
Ordering
Hoarding??
Unclear if even a subtype anymore
Bellini et al, 2023 - Pelvic floor movement irregularities disorder rates correlated with mental illness severity, including OCD
Constipation Issues
Urinary Issues - Ng et al, 2021
Harm OCD -
Pease et al. (2021) - sertraline use (300mg) in Harm- OCD lead to urinary stress or incontinence. though she did have 6 cups of coffee a day. Potentiation of cholinergic neuromuscular transmission within the detrusor muscle of the bladder through serotonin-induced activation, modulation of bladder sphincter tone, or interaction with downstream dopaminergic effects have all been proposed mechanisms for antidepressant-induced urinary incontinence. However, the exact mechanism behind this phenomenon remains unknown.
Sexual Dysfunction
Saad et al (2018)- Sexual dysfunctions in females with obsessive compulsive disorder were more common than healthy females especially (arousal, orgasm, satisfaction, pain and lubrication problems)
Saad et al (2018) - exposure CBT based treatments are somewhat ineffective at fixing maladaptive sex-based disgust responses, such as pelvic floor groinal response
Different training is needed
Padoa et al. 2021 - In both women and men, sexual function is significantly impaired by OPF (Overactive Pelvic floor) and genitopelvic pain penetration disorders are often the primary manifestation of this condition. Women with OPF report less sexual desire, arousal, and satisfaction; more difficulty reaching orgasm; lower frequencies of intercourse; more negative attitudes toward sexuality; and more sexual distress than women without sexual pain. The most frequently reported sexual dysfunctions in men with OPF include erectile dysfunction, premature ejaculation, and ejaculatory pain.
Quinton et al, 2022 - OCD and Pelvic floor disorders are often comorbid
Mar et al., 2022 - meta-analysis of SST in OCD - OCD Ps had worse performance on the task
Grant and Chamberlain, 2020 - putamen, globus pallidus higher in ocd
Significant evidence points to a role for anterior cingulate cortex (ACC) in the generation of OCD symptoms. Moreover, anterior cingulotomy, a neurosurgical procedure involving destruction of ACC gray matter and adjacent white matter tracts, has been associated with reduction of OCD symptoms in treatment refractory cases
Hyperactivity in VMPFC
Ahmari and Rauch, 2022
Maia et al., 2011 - Hyperactivity in ACC, Caudate Nucleus, OFC are all hyperactive at rest and may contribute to the generation of OCD Symptoms
Maia et al., 2011 - In particular, excessive relative activity in the direct pathway in OFC/ACC CBGTC loops has been suggested to result in a positive feedback loop in which obsessive thoughts become “trapped” (Baxter et al., 2001; Saxena et al., 2001; Saxena et al., 1998; Saxena & Rauch, 2000).
Caudate + Putamen = Striatum
OCD Prevalence is higher in Huntington's disease - disease that causes striatum degeneration (Beglinger et al., 2007)
Right Inferior frontal cortex impaired activity - de Wit et al., 2011
In OCD constant checking that a task has been performed can lead to memory ability being worsened, and thus executive dysfunction. This may relate to smaller frontal cortex (which modulates the hippocampus) and hippocampus volumes/activity.
Information processing
Muller & Roberts (2005) - consistent evidence suggesting impairment for non-verbal information, particularly for complex visual stimuli and the individual’s own actions. OCD seems to favour threatening information.
Emotional Memory Processing
Cougle et al. (2011) - OCD patients are less confident in their own recollective memory abilities compared to controls
Van den hout & Kindt (2003) - Repeated checking causes memory distrust
Some children develop OCD following streptococcal infection (Swedo, Leonard, & Garvey, 1998)
Questionaires
Foa et al (1998) - OCI - Obsessive compulsive inventory - 42 question, with 7 subscales: Washing, Checking, Doubting, Ordering, Obsessing (i.e., having obsessional thoughts), Hoarding, and Mental Neutralizing. Each item is rated on a 5-point (0-4) Likert scale of symptom frequency and associated distress.
Scoring on the sexual/religious obsessions dimension predicted poor treatment response to serotonergic medication in the Mataix-Cols et al. (2002) study, whereas Abramowitz et al. (2003) found that patients in their unacceptable thoughts subgroup, a group with high levels of mental compulsions, responded quite well to behaviour therapy.
Washers > Checkers & Obsessionals: Pattern Recognition (Kyrios, Wainwright, Purcell, Pantelis, and Maruff (1999a))
Longer Motor response time, but not a cognitive response time
effect size was small though
Intrusive thoughts
Salkovskis & Campbell, 1994 - Thought suppression induces intrusion in naturally occurring negative intrusive thoughts
More resistant to SSRIs (Hurley et al., 2002)
Ravindran et al., 2020 - patients with obsessions/checking rituals (n=10) showed severer memory deficits and decreased activity in the postcentral gyrus than patients with cleanliness/washing rituals (n=14)
On fMRI, the patients showed greater activation in the right dorsolateral prefrontal cortex (DLPFC), left superior temporal gyrus (STG), left insula, and cuneus during two-back task compared to the controls. Right orbitofrontal cortex activity showed a significant positive correlation with Y-BOCS scores in OCD
Distinct Neural Correlates of Washing, Checking, and Hoarding Symptom Dimensions in Obsessive-compulsive Disorder - Mataix-cols et al., 2004
Washing: Right Caudate Nucleus
Checking: Putamen, Globus pallidus, thalamus, and dorsal cortical areas
Hoarding: precentral gyrus and right orbitofrontal cortex
Conclusions - The findings suggest that different obsessive-compulsive symptom dimensions are mediated by relatively distinct components of frontostriatothalamic circuits implicated in cognitive and emotion processing. Obsessive-compulsive disorder may be best conceptualized as a spectrum of multiple, potentially overlapping syndromes rather than a unitary nosologic entity.
checking subtypes areas in question are basal ganglia areas and could potentially lead to the lowest performance on the stop signal task due to overactive(?) basal ganglia
"Rauch et al.,[1998] washing symptoms correlated with increased regional cerebral blood flow in bilateral anterior cingulate and left orbitofrontal"
Rauch et al. [1998] - checking symptoms correlated with increased regional cerebral blood flow in the striatum
Ordering/Symmetry - symmetry/ordering with reduced cerebral blood flow in the striatum
Murayama et al., 2013 - caudate and ACC are associated with checking rituals and that large cortical brain regions are related to washing rituals.
Van den huevel et al., 2009 - ‘symmetry/ordering’ dimension were negatively correlated with ‘global’ GM and WM volumes.
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