The neural bases of obsessive-compulsive disorder in children and adults

In the paper

“The other study (Castillo et al., 2005) failed to detect any differences between pre- and post-treatment scans.”

What the sources say

• Not checked yetcites Castillo et al., 2005

In the paper

“The age of onset of OCD seems to have a bimodal distribution, with a peak in childhood (at approximately 10 years of age) and another in early adulthood (Geller, 2006; Geller, Biederman, Jones, Shapiro et al., 1998).”

What the sources say

• Not checked yetcites Geller, 2006
• Not checked yetcites Geller et al., 1998

In the paper

“Conversely, one-third to one-half of adults with OCD have the onset of their symptoms in childhood or adolescence (Eichstedt & Arnold, 2001).”

What the sources say

• Not checked yetcites Eichstedt & Arnold, 2001

In the paper

“In addition, many studies report only the mean and standard deviation of age of illness onset, which are inadequate to characterize what are likely to be bimodal distributions.”

In the paper

“These studies show that even in the absence of obvious differences in behavioral performance, cognitive activation studies may highlight differences in neural activity that reflect compensatory strategies.”

In the paper

“Consequently, knowing whether findings apply to all adults with OCD or only to those with childhood- or adult-onset OCD is impossible for most existing studies that include adults with OCD.”

In the paper

“Cognitive activation studies therefore often have less face validity than resting, symptom provocation, or pre/post-treatment studies for addressing the neural bases of obsessive-compulsive symptoms.”

In the paper

“Compared to adult-onset OCD, childhood-onset OCD is more prevalent among males (Eichstedt & Arnold, 2001; Geller, Biederman, Jones, Shapiro et al., 1998)”

What the sources say

• Not checked yetcites Eichstedt & Arnold, 2001
• Not checked yetcites Geller et al., 1998

In the paper

“Early cognitive activation studies, for example, found that healthy controls recruited the striatum during performance of an implicit (habit) learning task, whereas patients with OCD recruited the hippocampus, despite similar behavioral performances across the groups (Rauch et al., 1997; Rauch et al., 2001).”

What the sources say

• Not checked yetcites Rauch et al., 1997 source
• Not checked yetcites Rauch et al., 2001

In the paper

“The OFC and ACC are intimately connected to the basal ganglia via cortico-basal ganglia-thalamo-cortical (CBGTC) loops (Alexander, DeLong, & Strick, 1986; Mega & Cummings, 2001; Middleton & Strick, 2001b).”

What the sources say

• Not checked yetcites Alexander et al., 1986
• Not checked yetcites Mega & Cummings, 2001
• Not checked yetcites Middleton & Strick, 2001b

In the paper

“adults with childhood-onset OCD respond less to treatment with clomipramine than do adults with adult-onset OCD, independent of illness duration or severity (Ackerman, Greenland, Bystritsky, Morgenstern, & Katz, 1994).”

What the sources say

• Not checked yetcites Ackerman et al., 1994

In the paper

“The main site in the striatum through which the CBGTC loops involving the OFC and ACC run is the head of the caudate nucleus (Alexander et al., 1986; Mega & Cummings, 2001; Middleton & Strick, 2001b).”

What the sources say

• Not checked yetcites Alexander et al., 1986
• Not checked yetcites Mega & Cummings, 2001
• Not checked yetcites Middleton & Strick, 2001b

In the paper

“These findings are not sufficient to establish causality, however, because anatomical alterations may themselves be a consequence rather than a cause of the symptoms.”

In the paper

“Functional imaging studies have reported with remarkable consistency hyperactivity in the orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), and caudate nucleus of patients with Obsessive-Compulsive Disorder (OCD).”

What the sources say

• Not checked yetcites Baxter et al., 2001
• Not checked yetcites Saxena et al., 2001
• Not checked yetcites Saxena et al., 1998 source

In the paper

“is more familial (Bellodi, Sciuto, Diaferia, Ronchi, & Smeraldi, 1992; do Rosario-Campos et al., 2005; Nestadt et al., 2000; Pauls, Alsobrook, Goodman, Rasmussen, & Leckman, 1995)”

What the sources say

• Not checked yetcites Bellodi et al., 1992
• Not checked yetcites do Rosario-Campos et al., 2005
• Not checked yetcites Nestadt et al., 2000

In the paper

“This interpretation remains controversial, however, because such hyperactivity may represent either a cause or a consequence of the symptoms.”

In the paper

“and is associated with a higher prevalence of tic disorders, both in the patients with OCD themselves and in their first-degree relatives (Chabane et al., 2005; Grados et al., 2001; Pauls et al., 1995).”

What the sources say

• Not checked yetcites Chabane et al., 2005
• Not checked yetcites Grados et al., 2001
• Not checked yetcites Pauls et al., 1995 source

In the paper

“These findings suggested that patients with OCD might use hippocampus-dependent (declarative) learning to overcome deficits in striatum-dependent (implicit) learning.”

In the paper

“Converging evidence from these various lines of research supports a causal role for the cortico-basal ganglia-thalamo-cortical loops that involve the OFC and ACC in the pathogenesis of OCD in children and adults.”

In the paper

“Patients with OCD exhibit behavioral deficits in at least some inhibitory control tasks (Chamberlain, Blackwell, Fineberg, Robbins, & Sahakian, 2005)”

What the sources say

• Not checked yetcites Chamberlain et al., 2005

In the paper

“However, much evidence suggests that repeatedly engaging in a class of behaviors or cognitive processes can change brain structure (Lazar et al., 2005; Mechelli et al., 2004; Pascual-Leone, 2001; Schlaug, 2001; Schlaug, Norton, Overy, & Winner, 2005).”

What the sources say

• Not checked yetcites Lazar et al., 2005
• Not checked yetcites Mechelli et al., 2004
• Not checked yetcites Pascual-Leone, 2001

In the paper

“Consistent with this idea, the prevalence of obsessive-compulsive symptoms is significantly greater in Huntington’s disease than in the general population (Anderson, Louis, Stern, & Marder, 2001; Beglinger et al., 2007; De Marchi & Mennella, 2000)”

What the sources say

• Not checked yetcites Anderson et al., 2001
• Not checked yetcites Beglinger et al., 2007
• Not checked yetcites De Marchi & Mennella, 2000

In the paper

“and some case reports describe the onset of OCD following the onset of Huntington’s disease (Cummings & Cunningham, 1992; Scicutella, 2000).”

What the sources say

• Not checked yetcites Cummings & Cunningham, 1992
• Not checked yetcites Scicutella, 2000

In the paper

“We know, for example, that when healthy controls are exposed to pictures depicting OCD-relevant scenes (specifically, pictures that are washing-relevant, checking-relevant, and hoarding-relevant) and are asked to imagine related scenarios (e.g., “imagine that you must come into contact with what’s shown in the following pictures without washing yourself afterward”), they activate regions similar”

What the sources say

• Not checked yetcites Mataix-Cols et al., 2003

In the paper

“The findings from the resting, symptom provocation, and pre/post-treatment studies described above may therefore be interpreted as implicating the CBGTC loops involving the OFC and ACC (henceforward referred to as OFC/ACC CBGTC loops) in OCD.”

In the paper

“Furthermore, demonstrating that lesions that affect certain brain circuits result in OCD does not, per se, prove a pathogenic role for those circuits in most cases of OCD.”

In the paper

“First, certain brain lesions due to accidents, stroke, and other naturalistic causes seem to cause OCD.”

In the paper

“We also know that the OFC and ACC are involved in emotion regulation (Ochsner, Bunge, Gross, & Gabrieli, 2002; Ochsner & Gross, 2005)”

What the sources say

• Not checked yetcites Ochsner et al., 2002
• Not checked yetcites Ochsner & Gross, 2005

In the paper

“Further support for this idea comes from the findings that the OFC, ACC, and caudate are activated in a variety of tasks that require the suppression of a prepotent response (Peterson, 2003).”

What the sources say

• Not checked yetcites Peterson, 2003

In the paper

“Weighing against this thesis are human lesion studies suggesting that response inhibition may be localized to the right inferior frontal cortex, rather than in the OFC, ACC, or caudate (Aron, Fletcher, Bullmore, Sahakian, & Robbins, 2003; Aron, Robbins, & Poldrack, 2004).”

What the sources say

• Not checked yetcites Aron et al., 2003
• Not checked yetcites Aron et al., 2004

In the paper

“Consistent with the idea that OFC activity plays an inhibitory role, keeping the obsessions, compulsions, or anxiety in check, greater activation of the OFC during symptom provocation is associated with a smaller increase in reported symptoms with the provocation (Adler et al., 2000; Rauch et al., 1994).”

What the sources say

• Not checked yetcites Adler et al., 2000
• Not checked yetcites Rauch et al., 1994

In the paper

“Several alternative interpretations of these findings are, however, equally plausible.”

In the paper

“This suggestion also fails to explain why some patients with OCD will, for example, obsess about germs and wash compulsively, whereas others may obsess about whether they have locked the doors to their house and check the locks compulsively.”

In the paper

“NAA levels may be more sensitive than volumetric measures to detect neuronal abnormalities (Bartha et al., 1998; Cendes, Andermann, Preul, & Arnold, 1994; Ebisu, Rooney, Graham, Weiner, & Maudsley, 1994).”

What the sources say

• Not checked yetcites Bartha et al., 1998
• Not checked yetcites Cendes et al., 1994
• Not checked yetcites Ebisu et al., 1994

In the paper

“N-acetyl-aspartate (NAA), one of those metabolites, has been of particular interest in studies of disease processes because decreases in NAA levels may indicate neuronal loss or dysfunction (Barker, 2001; Dager & Steen, 1992; Maier, 1995).”

What the sources say

• Not checked yetcites Barker, 2001
• Not checked yetcites Dager & Steen, 1992
• Not checked yetcites Maier, 1995

In the paper

“Several valuable animal models of OCD have been developed in efforts to study causal mechanisms in OCD more directly (Joel, 2006; Korff & Harvey, 2006).”

What the sources say

• Not checked yetcites Joel, 2006
• Not checked yetcites Korff & Harvey, 2006

In the paper

“This idea is supported by the finding that the ACC and the head of the caudate nucleus are activated when patients with Tourette’s syndrome (TS) voluntarily inhibit their tics (Peterson et al., 1998).”

What the sources say

• Not checked yetcites Peterson et al., 1998

In the paper

“Third, several neurosurgical procedures make localized lesions in attempts to provide symptom-relief in severe, treatment-refractory cases of OCD.”

In the paper

“This theory of OCD is not without difficulties, though. In particular, it does not explain why patients with OCD should have specific obsessions, as opposed to obsessing about everything.”

In the paper

“Moreover, an improvement in symptoms following certain neurosurgical lesions does not, per se, prove that the circuits that were lesioned caused the symptoms (just as having a gastric bypass surgery and losing weight as a result does not prove that the cause of excess weight was an enlarged stomach).”

In the paper

“Several studies have reported bilateral reductions in OFC volumes in adults with OCD (Atmaca et al., 2006; Atmaca, Yildirim, Ozdemir, Tezcan, & Poyraz, 2007; Szeszko et al., 1999); one study reported a volume reduction only in the left OFC (Kang et al., 2004).”

What the sources say

• Not checked yetcites Atmaca et al., 2006
• Not checked yetcites Atmaca et al., 2007
• Not checked yetcites Szeszko et al., 1999

In the paper

“Thus, even anatomical differences in the brains of patients with OCD may be a consequence rather than a cause of the disorder.”

In the paper

“The problem is that, like functional imaging studies, anatomical studies only provide information about the correlates of the disorder.”

In the paper

“and to be larger post-treatment in patients who responded to a trial of selective serotonin reuptake inhibitors than in treatment-naïve or treatment-refractory patients (Atmaca et al., 2006).”

What the sources say

• Not checked yetcites Atmaca et al., 2006

In the paper

“disturbances in only one or two of those loops (e.g., the ones involving the OFC and ACC) may not be of sufficient magnitude to yield differences in overall caudate volume.”

In the paper

“The few studies that have measured volumes of the globus pallidus or overall volumes of the lenticular nuclei in adults with OCD generally failed to detect differences from healthy controls (Choi et al., 2007; Jenike et al., 1996; Luxenberg et al., 1988).”

What the sources say

• Not checked yetcites Choi et al., 2007
• Not checked yetcites Jenike et al., 1996
• Not checked yetcites Luxenberg et al., 1988 source

In the paper

“Patients who responded to medication treatment had smaller thalami post-treatment than either treatment-naïve or treatment-refractory patients, with no differences detected between the latter two groups (Atmaca et al., 2006).”

What the sources say

• Not checked yetcites Atmaca et al., 2006

In the paper

“but a third study failing to detect such differences (Sumitani et al., 2007).”

What the sources say

• Not checked yetcites Sumitani et al., 2007

In the paper

“Studies comparing caudate volumes in adults with OCD and healthy controls have yielded highly variable findings.”

In the paper

“One study reported increased ventral striatum volumes in adults with OCD (Cardoner et al., 2007).”

What the sources say

• Not checked yetcites Cardoner et al., 2007

In the paper

“A study that measured specifically the volume of the medial OFC also found it to be reduced bilaterally in adults with OCD (Cardoner et al., 2007).”

What the sources say

• Not checked yetcites Cardoner et al., 2007

In the paper

“these findings may indicate the presence of subtle neuronal abnormalities in the ACC of adults with OCD.”

In the paper

“different portions of the caudate could differ from healthy controls both in the direction and magnitude of the effect.”

In the paper

“Different portions of the caudate participate in different CBGTC loops”

In the paper

“Other areas that strongly influence the OFC/ACC CBGTC loops, by virtue of their projections to the same regions of the striatum as the OFC or ACC, include the superior temporal gyrus and hippocampus (Alexander et al., 1986; Middleton & Strick, 2001b).”

What the sources say

• Not checked yetcites Alexander et al., 1986
• Not checked yetcites Middleton & Strick, 2001b

In the paper

“Several studies have compared ACC volumes in adults with OCD and normal controls, but have generally failed to detect significant differences (Atmaca et al., 2006; Atmaca et al., 2007; Grachev et al., 1998; Kellner et al., 1991; Riffkin et al., 2005; Szeszko et al., 1999), even when the ACC has been subdivided into anterior and posterior regions (Kang et al., 2004).”

What the sources say

• Not checked yetcites Atmaca et al., 2006
• Not checked yetcites Atmaca et al., 2007
• Not checked yetcites Grachev et al., 1998

In the paper

“Although most studies have not detected significant differences (Atmaca et al., 2006; Atmaca et al., 2007; Aylward et al., 1996; Kang et al., 2004; Kellner et al., 1991; Riffkin et al., 2005)”

What the sources say

• Not checked yetcites Atmaca et al., 2006
• Not checked yetcites Atmaca et al., 2007
• Not checked yetcites Aylward et al., 1996

In the paper

“Volumes of the subthalamic nucleus have not been assessed because this is a small, poorly demarcated structure that is exceedingly difficult to measure.”

In the paper

“Two studies failed to detect differences in volumes of the thalamus between adults with OCD and healthy controls (Kang et al., 2004; Kwon et al., 2003).”

What the sources say

• Not checked yetcites Kang et al., 2004
• Not checked yetcites Kwon et al., 2003

In the paper

“although no significant correlation was detected between increases in NAA and decreases in symptom severity.”

What the sources say

• Not checked yetcites Jang et al., 2006

In the paper

“but two studies failed to detect significant differences in volumes of the head of the caudate between adults with OCD and healthy controls (Bartha et al., 1998; Kellner et al., 1991).”

What the sources say

• Not checked yetcites Bartha et al., 1998
• Not checked yetcites Kellner et al., 1991

In the paper

“Two studies failed to detect volumetric abnormalities in the hippocampus of adults with OCD (Jenike et al., 1996; Szeszko et al., 1999)”

What the sources say

• Not checked yetcites Jenike et al., 1996
• Not checked yetcites Szeszko et al., 1999

In the paper

“Several 1H-MRS studies have reported decreased levels of NAA in the ACC of adults with OCD (Ebert et al., 1997; Jang et al., 2006; Sumitani, Harada, Kubo, & Ohmori, 2007; Yucel et al., 2007).”

What the sources say

• Not checked yetcites Ebert et al., 1997
• Not checked yetcites Jang et al., 2006
• Not checked yetcites Sumitani et al., 2007

In the paper

“Most components of the OFC/ACC CBGTC loops – the OFC, ACC, striatum, and thalamus – have been relatively well investigated in ROI studies.”

In the paper

“Furthermore, treatment with the selective serotonin reuptake inhibitor citalopram increases levels of NAA in the ACC (and other regions of prefrontal cortex) in adults with OCD (Jang et al., 2006)”

What the sources say

• Not checked yetcites Jang et al., 2006

In the paper

“one study reported a volume reduction only in the left OFC (Kang et al., 2004).”

What the sources say

• Not checked yetcites Kang et al., 2004

In the paper

“Volume increases in the head of the caudate and ventral striatum, if confirmed, would provide additional evidence for the involvement of OFC/ACC CBGTC loops in OCD, since these are the regions of the striatum through which such loops run.”

In the paper

“The variability in findings for the caudate may be, in part, a consequence of the heterogeneous nature of the circuits that traverse it.”

In the paper

“suggesting that the findings of smaller thalami in treatment-responding adults may also have been a consequence of treatment.”

In the paper

“two studies have reported decreased caudate volumes in OCD (Luxenberg et al., 1988; D. Robinson et al., 1995).”

What the sources say

• Not checked yetcites Luxenberg et al., 1988 source
• Not checked yetcites D. Robinson et al., 1995

In the paper

“An area that is closely related, anatomically and functionally, to the OFC and ACC is the amygdala (Amaral, Price, Pitkanen, & Carmichael, 1992; Carmichael & Price, 1995; Cavada, Company, Tejedor, Cruz-Rizzolo, & Reinoso-Suarez, 2000; Rolls, 1999; Zald & Kim, 2001).”

What the sources say

• Not checked yetcites Amaral et al., 1992
• Not checked yetcites Carmichael & Price, 1995
• Not checked yetcites Cavada et al., 2000

In the paper

“Thalamic volumes were found to correlate positively with symptom severity in both treatment-naïve and treatment-refractory patients (Atmaca et al., 2006; Atmaca et al., 2007).”

What the sources say

• Not checked yetcites Atmaca et al., 2006
• Not checked yetcites Atmaca et al., 2007

In the paper

“However, two other key components of these loops – the globus pallidus and the subthalamic nucleus – remain largely unstudied.”

In the paper

“The fact that the reductions in NAA are reversible with administration of citalopram (Jang et al., 2006)”

What the sources say

• Not checked yetcites Jang et al., 2006

In the paper

“suggests that those reductions may reflect reversible abnormalities either in metabolic processes or in neuropil (axonal or dendritic arbors and synapses), rather than reductions in the number of neurons (Barker, 2001).”

What the sources say

• Not checked yetcites Barker, 2001

In the paper

“Volumes of the thalamus have been reported to be larger in treatment-naïve adults with OCD than in healthy controls (Atmaca et al., 2006; Atmaca et al., 2007).”

What the sources say

• Not checked yetcites Atmaca et al., 2006
• Not checked yetcites Atmaca et al., 2007

In the paper

“with two studies reporting decreased levels of NAA in the striatum of adults with OCD (Bartha et al., 1998; Ebert et al., 1997)”

What the sources say

• Not checked yetcites Bartha et al., 1998
• Not checked yetcites Ebert et al., 1997

In the paper

“One study reported increases in the volume of the head of the right caudate in adults with OCD (Scarone et al., 1992)”

What the sources say

• Not checked yetcites Scarone et al., 1992

In the paper

“Increases in gray matter have also been reported in the thalamus (J. J. Kim et al., 2001; Yoo et al., 2008).”

What the sources say

• Not checked yetcites J. J. Kim et al., 2001
• Not checked yetcites Yoo et al., 2008

In the paper

“One of these studies focused on the hippocampus and reported shape changes concentrated on the hippocampus head (Hong et al., 2007).”

What the sources say

• Not checked yetcites Hong et al., 2007

In the paper

“and another reporting an increase in left amygdala volume (Kwon et al., 2003).”

What the sources say

• Not checked yetcites Kwon et al., 2003

In the paper

“Increases in gray matter have generally been reported in the striatum (Pujol et al., 2004; Valente et al., 2005; Yoo et al., 2008).”

What the sources say

• Not checked yetcites Pujol et al., 2004
• Not checked yetcites Valente et al., 2005
• Not checked yetcites Yoo et al., 2008

In the paper

“the finding of thinning in the superior temporal cortex is consistent with the volume reductions that have been reported for the superior temporal gyrus (Choi et al., 2006)”

What the sources say

• Not checked yetcites Choi et al., 2006

In the paper

“The other study focused on the basal ganglia and found outward deformities concentrated in the dorsal anterior caudate nucleus bilaterally and, to a lesser extent, in the ventral lateral part of the left putamen (Choi et al., 2007).”

What the sources say

• Not checked yetcites Choi et al., 2007

In the paper

“These increases have included the ventral striatum (Pujol et al., 2004), which is consistent with the known neuroanatomy of OFC/ACC CBGTC loops, but also the putamen (Valente et al., 2005; Yoo et al., 2008)”

What the sources say

• Not checked yetcites Pujol et al., 2004
• Not checked yetcites Valente et al., 2005
• Not checked yetcites Yoo et al., 2008

In the paper

“ROI approaches suffer from two serious limitations.”

In the paper

“1H-MRS studies in adults with OCD provide convincing evidence for decreased NAA levels in the ACC”

In the paper

“and inconsistent evidence for caudate or striatum volumes.”

In the paper

“Findings from these studies have been generally consistent with the pathohpysiological model of OCD that emphasizes the OFC and ACC and their loops through the basal ganglia.”

In the paper

“and suggestive evidence for decreased NAA levels in the striatum.”

In the paper

“The only other areas for which abnormalities have been found in at least two VBM studies in adults with OCD are the insula (J. J. Kim et al., 2001; Pujol et al., 2004; Valente et al., 2005; Yoo et al., 2008) and cerebellum (J. J. Kim et al., 2001; Pujol et al., 2004).”

What the sources say

• Not checked yetcites J. J. Kim et al., 2001
• Not checked yetcites Pujol et al., 2004
• Not checked yetcites Valente et al., 2005

In the paper

“Together, these findings point to abnormalities in volumes or NAA levels in all components of the OFC/ACC CBGTC loops that have been studied in detail.”

In the paper

“Only two studies, both by the same group and in adults, have used surface analysis to analyze subcortical structures in OCD.”

In the paper

“with one study reporting bilateral reductions in amygdala volume (Szeszko et al., 1999)”

What the sources say

• Not checked yetcites Szeszko et al., 1999

In the paper

“anatomical ROIs may not correspond to functionally meaningful units because gross anatomical structures or landmarks do not always reflect anatomical connectivity or cytoarchitecture.”

In the paper

“Volumetric studies in adults with OCD provide convincing evidence for reduced OFC volumes”

In the paper

“Several studies have used voxel-based morphometry (VBM) to compare gray matter in adults with OCD and healthy controls (J. J. Kim et al., 2001; Pujol et al., 2004; Valente et al., 2005; Yoo et al., 2008).”

What the sources say

• Not checked yetcites J. J. Kim et al., 2001
• Not checked yetcites Pujol et al., 2004
• Not checked yetcites Valente et al., 2005

In the paper

“Both increases (J. J. Kim et al., 2001; Valente et al., 2005) and decreases (Pujol et al., 2004; Valente et al., 2005) in gray matter have been reported for differing subregions of the OFC”

What the sources say

• Not checked yetcites J. J. Kim et al., 2001
• Not checked yetcites Valente et al., 2005
• Not checked yetcites Pujol et al., 2004

In the paper

“suggestive evidence for increased thalamic and normal ACC volumes”

In the paper

“Decreases in gray matter have been consistently reported in the ACC and surrounding medial frontal gyrus (Pujol et al., 2004; Valente et al., 2005; Yoo et al., 2008).”

What the sources say

• Not checked yetcites Pujol et al., 2004
• Not checked yetcites Valente et al., 2005
• Not checked yetcites Yoo et al., 2008

In the paper

“suggestive evidence for increased thalamic and normal ACC volumes”

In the paper

“Abnormalities in closely related areas, such as the hippocampus, amygdala, and superior temporal gyrus, have also been reported.”

In the paper

“It remains controversial, however, because errors in spatial normalization may confound all subsequent computations, resulting in unreliable findings (Bookstein, 2001).”

What the sources say

• Not checked yetcites Bookstein, 2001

In the paper

“Nevertheless, it is noteworthy that these abnormalities occur in the medial thalamus, where the mediodorsal nucleus – the primary nucleus of the thalamus in OFC/ACC CBGTC loops – is located.”

In the paper

“Significantly fewer volumetric or 1H-MRS studies exist for children than for adults with OCD.”

In the paper

“No cortical thickness or surface analysis studies of children with OCD have been reported in the literature.”

In the paper

“However, two VBM studies have been recently published (Carmona et al., 2007; Gilbert et al., 2008).”

What the sources say

• Not checked yetcites Carmona et al., 2007
• Not checked yetcites Gilbert et al., 2008

In the paper

“The first such study detected reduced ratios of NAA to choline and NAA to creatine/phosphocreatine + choline levels in the medial but not the lateral thalami of treatment-naïve children with OCD (Fitzgerald, Moore, Paulson, Stewart, & Rosenberg, 2000).”

What the sources say

• Not checked yetcites Fitzgerald, Moore, Paulson, Stewart, & Rosenberg, 2000

In the paper

“One cross-sectional study reported a nearly significant correlation between age and ACC volumes in healthy children but not in children with OCD (Rosenberg & Keshavan, 1998).”

What the sources say

• Not checked yetcites Rosenberg & Keshavan, 1998

In the paper

“One study reported smaller globus pallidus volumes in medication-naïve children with OCD compared with matched healthy controls (Szeszko, MacMillan, McMeniman, Chen et al., 2004).”

What the sources say

• Not checked yetcites Szeszko, MacMillan, McMeniman, Chen et al., 2004

In the paper

“One study reported increased thalamic volumes in medication-naïve children with OCD that decreased to normal levels following treatment with the selective serotonin reuptake inhibitor paroxetine (Gilbert et al., 2000).”

What the sources say

• Not checked yetcites Gilbert et al., 2000

In the paper

“Most extant volumetric and 1H-MRS studies of OCD have focused on comparing volumes or metabolite levels between patients with OCD and healthy controls, paying little to no attention to how the volumes or metabolite levels change with age in persons with and without OCD.”

In the paper

“A possible explanation for this discrepancy comes from the observation that, depending on the details of the VBM procedure used, VBM may characterize gray matter density rather than volume (Good et al., 2001).”

What the sources say

• Not checked yetcites Good et al., 2001