Deep brain stimulation of the ventral capsule/ventral striatum for treatment-resistant depression

BACKGROUND

We investigated the use of deep brain stimulation (DBS) of the ventral capsule/ventral striatum (VC/VS) for treatment refractory depression.

METHODS

Fifteen patients with chronic, severe, highly refractory depression received open-label DBS at three collaborating clinical sites. Electrodes were implanted bilaterally in the VC/VS region. Stimulation was titrated to therapeutic benefit and the absence of adverse effects. All patients received continuous stimulation and were followed for a minimum of 6 months to longer than 4 years. Outcome measures included the Hamilton Depression Rating Scale-24 item (HDRS), the Montgomery-Asberg Depression Rating Scale (MADRS), and the Global Assessment of Function Scale (GAF).

RESULTS

Significant improvements in depressive symptoms were observed during DBS treatment. Mean HDRS scores declined from 33.1 at baseline to 17.5 at 6 months and 14.3 at last follow-up. Similar improvements were seen with the MADRS (34.8, 17.9, and 15.7, respectively) and the GAF (43.4, 55.5, and 61.8, respectively). Responder rates with the HDRS were 40% at 6 months and 53.3% at last follow-up (MADRS: 46.7% and 53.3%, respectively). Remission rates were 20% at 6 months and 40% at last follow-up with the HDRS (MADRS: 26.6% and 33.3%, respectively). The DBS was well-tolerated in this group.

CONCLUSIONS

Deep brain stimulation of the VC/VS offers promise for the treatment of refractory major depression.

Gender differences in genetic linkage and association on 11p15 in obsessive-compulsive disorder families

Several clinical and genetic studies have reported gender differences in obsessive-compulsive disorder (OCD). Previously, we conducted a linkage genome scan using multipoint allele-sharing methods to test for linkage in 219 families participating in the OCD Collaborative Genetics Study. When these families were stratified by proband's gender, suggestive linkage to chromosome 11p15 at marker D11S2362 (KAC(all) = 2.92, P = 0.00012) was detected in families with male probands, but not in the ones with female probands. We have since conducted fine mapping with a denser microsatellite marker panel in the region of 11p15, and detected a significant linkage signal at D11S4146 (KAC(all) = 5.08, P < 0.00001) in the families of male probands. Subsequently, 632 SNPs were genotyped spanning a 4.0 Mb region of the 1 LOD unit interval surrounding the linkage peak in the original families and an additional 165 families. Six SNPs were associated with OCD (P < 0.001): two SNPs were identified when all the families were included, and four SNPs only in male proband families. No SNP showed significant association with the OCD phenotype only in the families with a female proband. The results suggest a possible gender effect in the etiology of OCD.

Further development of YBOCS dimensions in the OCD Collaborative Genetics study: symptoms vs. categories

Despite progress in identifying homogeneous subphenotypes of obsessive-compulsive disorder (OCD) through factor analysis of the Yale Brown Obsessive-Compulsive Scale Symptom Checklist (YBOCS-SC), prior solutions have been limited by a reliance on presupposed symptom categories rather than discrete symptoms. Furthermore, there have been few attempts to evaluate the familiality of OCD symptom dimensions. The purpose of this study was to extend prior work by this collaborative group in category-based dimensions by conducting the first-ever exploratory dichotomous factor analysis using individual OCD symptoms, comparing these results to a refined category-level solution, and testing the familiality of derived factors. Participants were 485 adults in the six-site OCD Collaborative Genetics Study, diagnosed with lifetime OCD using semi-structured interviews. YBOCS-SC data were factor analyzed at both the individual item and symptom category levels. Factor score intraclass correlations were calculated using a subsample of 145 independent affected sib pairs. The item- and category-level factor analyses yielded nearly identical 5-factor solutions. While significant sib-sib associations were found for four of the five factors, Hoarding and Taboo Thoughts were the most robustly familial (r ICC>or=0.2). This report presents considerable converging evidence for a five-factor structural model of OCD symptoms, including separate factor analyses employing individual symptoms and symptom categories, as well as sibling concordance. The results support investigation of this multidimensional model in OCD genetic linkage studies.

Sex-specific clinical correlates of hoarding in obsessive-compulsive disorder

Little is known about whether the clinical correlates of hoarding behavior are different in men and women with obsessive-compulsive disorder (OCD). In the current study, we evaluated the association of hoarding with categories of obsessions and compulsions, psychiatric disorders, personality dimensions, and other clinical characteristics separately in 151 men and 358 women with OCD who were examined during the OCD Collaborative Genetics Study. We found that, among men but not women, hoarding was associated with aggressive, sexual, and religious obsessions and checking compulsions. In men, hoarding was associated with generalized anxiety disorder and tics whereas, among women, hoarding was associated with social phobia, post-traumatic stress disorder, body dysmorphic disorder, nail biting, and skin picking. In women but not men, hoarding was associated with schizotypal and dependent personality disorder dimensions, and with low conscientiousness. These findings indicate that specific clinical correlates of hoarding in OCD are different in men and women and may reflect sex-specific differences in the course, expression, and/or etiology of hoarding behavior in OCD.

Demographic and clinical characteristics associated with treatment status in family members with obsessive-compulsive disorder

This study investigated the demographic and clinical factors that influence treatment status in family members with obsessive compulsive disorder (OCD). Six hundred and two subjects from the OCD Collaborative Genetics Study were interviewed using the Structured Clinical Interview for DSM-IV (SCID) to diagnose Axis I disorders, and the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) for assessment of OCD symptoms. The demographic and clinical data were compared between subjects who had received treatment and those who had not. A precipitous onset of symptoms, severe illness, multiple obsessions and compulsions, and co-morbid affective disorders were all positively associated with receiving treatment. Older age and the presence of obsessive compulsive personality disorder (OCPD) or OCPD traits were negatively associated with treatment. Gender and age at onset of symptoms did not predict treatment history. The mean duration from onset of symptoms to receiving treatment was 13.8+/-SD 11.9 years, but there was a direct relationship between current age and time to treatment, with younger subjects receiving treatment sooner. Clinical factors are predominant in predicting treatment status in family members with OCD. Although the mean duration from onset of symptoms to treatment was long, younger family members appear to receive treatment sooner.

Anatomy and physiology of the basal ganglia: implications for DBS in psychiatry

The basal ganglia have been a target for neuromodulation surgery since Russell Meyers' pioneering works in the late 1930s. Contemporary movement disorder surgery on the brain has evolved from empiric observations on movement behavior after neurological lesions. So too has the development of psychiatric surgical procedures followed the observation of lesions in the brain on cognitive and affective behavior. Just as deep brain stimulation (DBS) has revolutionized the practice of movement disorder surgery, its application to psychiatric illness has become the cutting edge of functional and restorative neurosurgery. The fundamental concept of the cortico-striatal-pallido-thalamocortical loop will be explored in the context of psychiatric disorders. DBS targeting this circuitry appears from initial evidence in obsessive-compulsive disorder (OCD) to be a promising option for patients with neuropsychiatric illness resistant to conventional therapies. Further exploring the anatomic interconnectivity of the physiologically relevant cortical and subcortical areas will inevitably lead to better applications of DBS for the treatment of OCD, major depression (MD) and potentially for other psychiatric disorders. Implementing such therapies optimally will require the creation of treatment centers with specialized expertise in the psychiatric, neurosurgical, and ethical issues that arise with these populations.

Taboo thoughts and doubt/checking: a refinement of the factor structure for obsessive-compulsive disorder symptoms

The purpose of this report was to improve upon earlier factor analyses of obsessive-compulsive disorder (OCD) symptom categories by minimizing the heterogeneity in the aggressive obsessions category. An exploratory factor analysis was conducted on data from 293 adults with primary OCD. The resulting five factors (Symmetry/Ordering, Hoarding, Doubt/Checking, Contamination/Cleaning, and Taboo Thoughts) are phenomenologically more homogeneous than prior category-based factors and are consistent with those derived in previous item-level analyses.

A pilot study of moderate-intensity aerobic exercise for obsessive compulsive disorder

This preliminary study examined the impact of aerobic exercise as an adjunctive intervention to regular care in reducing obsessive compulsive disorder (OCD) symptoms in a clinical sample. Fifteen patients (53% male; mean age = 44.4 years) receiving behavioral therapy and/or pharmacotherapy for OCD and who still demonstrated clinically significant OCD symptoms (i.e., Yale-Brown obsessive compulsive scale, Y-BOCS scores above 16) were enrolled in a 12-week moderate-intensity exercise intervention. Measures of OCD symptom severity were obtained at baseline, end of treatment, and at 3- and 6-week, and 6-month follow-up. Study findings at the end of this 12-week aerobic exercise intervention point to a beneficial effect (Cohen's d = 1.69) on reduction in OCD symptom severity. Further, reductions in OCD symptom severity appear to persist 6 months later. Lastly, improvement in overall sense of well-being was observed after the 12-week intervention. Results of this study suggest that a randomized clinical trial evaluating the efficacy of this 12-week aerobic exercise intervention is warranted.

Hoarding in obsessive–compulsive disorder: Results from the OCD Collaborative Genetics Study

Hoarding behavior occurs frequently in obsessive-compulsive disorder (OCD). Results from previous studies suggest that individuals with OCD who have hoarding symptoms are clinically different than non-hoarders and may represent a distinct clinical group. In the present study, we compared 235 hoarding to 389 non-hoarding participants, all of whom had OCD, collected in the course of the OCD Collaborative Genetics Study. We found that, compared to non-hoarding individuals, hoarders were more likely to have symmetry obsessions and repeating, counting, and ordering compulsions; poorer insight; more severe illness; difficulty initiating or completing tasks; and indecision. Hoarders had a greater prevalence of social phobia and generalized anxiety disorder. Hoarders also had a greater prevalence of obsessive-compulsive and dependent personality disorders. Five personality traits were independently associated with hoarding: miserliness, preoccupation with details, difficulty making decisions, odd behavior or appearance, and magical thinking. Hoarding and indecision were more prevalent in the relatives of hoarding than of non-hoarding probands. Hoarding in relatives was associated with indecision in probands, independently of proband hoarding status. The findings suggest that hoarding behavior may help differentiate a distinct clinical subgroup of people with OCD and may aggregate in some OCD families. Indecision may be a risk factor for hoarding in these families.

Significant linkage to compulsive hoarding on chromosome 14 in families with obsessive-compulsive disorder: results from the OCD Collaborative Genetics Study

OBJECTIVE

Individuals with obsessive-compulsive disorder (OCD) who have compulsive hoarding behavior are clinically different from other OCD-affected individuals. The objective of this study was to determine whether there are chromosomal regions specifically linked to compulsive hoarding behavior in families with obsessive-compulsive disorder.

METHODS

The authors used multipoint allele-sharing methods to assess for linkage in 219 multiplex OCD families collected as part of the OCD Collaborative Genetics Study. The authors treated compulsive hoarding as the phenotype of interest and also stratified families into those with and without two or more relatives affected with compulsive hoarding.

RESULTS

Using compulsive hoarding as the phenotype, there was suggestive linkage to chromosome 14 at marker D14S588 (Kong and Cox logarithm of the odds ratio [LOD] [KAC(all)=2.9]). In families with two or more hoarding relatives, there was significant linkage of OCD to chromosome 14 at marker C14S1937 (KAC(all)=3.7), whereas in families with fewer than two hoarding relatives, there was suggestive linkage to chromosome 3 at marker D3S2398 (KAC(all)=2.9).

CONCLUSIONS

The findings suggest that a region on chromosome 14 is linked with compulsive hoarding behavior in families with OCD.

Familiality of factor analysis-derived YBOCS dimensions in OCD-affected sibling pairs from the OCD Collaborative Genetics Study

BACKGROUND

Identification of familial, more homogenous characteristics of obsessive-compulsive disorder (OCD) may help to define relevant subtypes and increase the power of genetic and neurobiological studies of OCD. While factor-analytic studies have found consistent, clinically meaningful OCD symptom dimensions, there have been only limited attempts to evaluate the familiality and potential genetic basis of such dimensions.

METHODS

Four hundred eighteen sibling pairs with OCD were evaluated using the Structured Clinical Interview for DSM-IV and the Yale-Brown Obsessive Compulsive Scale (YBOCS) Symptom Checklist and Severity scales.

RESULTS

After controlling for sex, age, and age of onset, robust sib-sib intraclass correlations were found for two of the four YBOCS factors: Factor IV (hoarding obsessions and compulsions (p = .001) and Factor I (aggressive, sexual, and religious obsessions, and checking compulsions; p = .002). Smaller, but still significant, familiality was found for Factor III (contamination/cleaning; p = .02) and Factor II (symmetry/ordering/arranging; p = .04). Limiting the sample to female subjects more than doubled the familiality estimates for Factor II (p = .003). Among potentially relevant comorbid conditions for genetic studies, bipolar I/II and major depressive disorder were strongly associated with Factor I (p < .001), whereas ADHD, alcohol dependence, and bulimia were associated with Factor II (p < .01).

CONCLUSIONS

Factor-analyzed OCD symptom dimensions in sibling pairs with OCD are familial with some gender-dependence, exhibit relatively specific relationships to comorbid psychiatric disorders and thus may be useful as refined phenotypes for molecular genetic studies of OCD.

The brown longitudinal obsessive compulsive study: treatments received and patient impressions of improvement

OBJECTIVE

The primary aim of this study was to assess the extent to which individuals with obsessive-compulsive disorder (OCD) received recommended doses of treatment and perceived a response to these treatments.

METHOD

Participants were 293 adults with primary OCD (DSM-IV) who were enrolled in the Brown Longitudinal Obsessive Compulsive Study, a naturalistic, prospective study of course in OCD. Data were collected at intake interviews between June 2001 and October 2004. Patient impressions of response to treatments received were assessed using the Clinical Global Impressions-Improvement Scale-patient version.

RESULTS

Of the 182 participants taking recommended doses of serotonin reuptake inhibitors (SRIs) at intake, 112 (62%) rated themselves as being very much or much improved. The remaining participants rated themselves as minimally improved, unchanged, or worse while taking recommended doses of SRIs. These participants (N = 70) reported receiving their current SRI for a mean (SD) of 2.7 (3.2) years. Twelve (29%) of the 42 participants receiving neuroleptic augmentation of SRIs reported a response. Thirty-eight percent of the sample received the recommended number of 13 sessions of cognitive-behavioral therapy (CBT) lifetime. Only 24% reported completing a continuous course of 13 weekly sessions. Eighteen (67%) of the 27 participants who received a course of CBT in the past year rated themselves as very much or much improved.

CONCLUSIONS

In this large, naturalistic study of OCD, over one third of participants receiving recommended doses of SRIs did not perceive substantial long-term benefit from pharmaco-therapy. Relatively few participants received recommended doses of CBT. Clinical implications and future directions are discussed.

Three-year outcomes in deep brain stimulation for highly resistant obsessive-compulsive disorder

Deep brain stimulation (DBS) of the anterior limb of the internal capsule has been shown to be beneficial in the short term for obsessive-compulsive disorder (OCD) patients who exhaust conventional therapies. Nuttin et al, who published the first DBS for OCD series, found promising results using a capsule target immediately rostral to the anterior commissure extending into adjacent ventral capsule/ventral striatum (VC/VS). Published long-term outcome data are limited to four patients. In this collaborative study, 10 adult OCD patients meeting stringent criteria for severity and treatment resistance had quadripolar stimulating leads implanted bilaterally in the VC/VS. DBS was activated openly 3 weeks later. Eight patients have been followed for at least 36 months. Group Yale-Brown Obsessive Compulsive Scale (YBOCS) scores decreased from 34.6+/-0.6 (mean+/-SEM) at baseline (severe) to 22.3+/-2.1 (moderate) at 36 months (p < 0.001). Four of eight patients had a > or =35% decrease in YBOCS severity at 36 months; in two patients, scores declined between 25 and 35%. Global Assessment of Functioning scores improved from 36.6+/-1.5 at baseline to 53.8+/-2.5 at 36 months (p < 0.001). Depression and anxiety also improved, as did self-care, independent living, and work, school, and social functioning. Surgical adverse effects included an asymptomatic hemorrhage, a single seizure, and a superficial infection. Psychiatric adverse effects included transient hypomanic symptoms, and worsened depression and OCD when DBS was interrupted by stimulator battery depletion. This open study found promising long-term effects of DBS in highly treatment-resistant OCD.

Genomewide linkage scan for obsessive-compulsive disorder: evidence for susceptibility loci on chromosomes 3q, 7p, 1q, 15q, and 6q

Obsessive-compulsive disorder (OCD) is the tenth most disabling medical condition worldwide. Twin and family studies implicate a genetic etiology for this disorder, although specific genes have yet to be identified. Here, we present the first large-scale model-free linkage analysis of both extended and nuclear families using both 'broad' (definite and probable diagnoses) and 'narrow' (definite only) definitions of OCD. We conducted a genome-scan analysis of 219 families collected as part of the OCD Collaborative Genetics Study. Suggestive linkage signals were revealed by multipoint analysis on chromosomes 3q27-28 (P=0.0003), 6q (P=0.003), 7p (P=0.001), 1q (P=0.003), and 15q (P=0.006). Using the 'broad' OCD definition, we observed the strongest evidence for linkage on chromosome 3q27-28. The maximum overall Kong and Cox LODall score (2.67) occurred at D3S1262 and D3S2398, and simulation based P-values for these two signals were 0.0003 and 0.0004, respectively, although for both signals, the simulation-based genome-wide significance levels were 0.055. Covariate-linkage analyses implicated a possible role of gene(s) on chromosome 1 in increasing the risk for an earlier onset form of OCD. We are currently pursuing fine mapping in the five regions giving suggestive signals, with a particular focus on 3q27-28. Given probable etiologic heterogeneity in OCD, mapping gene(s) involved in the disorder may be enhanced by replication studies, large-scale family-based linkage studies, and the application of novel statistical methods.

A functional neuroimaging investigation of deep brain stimulation in patients with obsessive-compulsive disorder

OBJECT

Deep brain stimulation (DBS) of the ventral [anterior internal] capsule/ventral striatum (VC/VS) is under investigation as an alternative to anterior capsulotomy for severe obsessive-compulsive disorder (OCD). In neuroimaging studies of patients with OCD, dysfunction in the orbitofrontal and anterior cingulate cortex, striatum, and thalamus has been identified; and modulation of activity in this circuit has been observed following successful nonsurgical treatment. The purpose of the current study was to test hypotheses regarding changes in regional cerebral blood flow (rCBF) during acute DBS at the VC/VS target in patients with OCD who were participating in a clinical DBS trial.

METHODS

Six patients enrolled in a DBS trial for OCD underwent positron emission tomography to measure rCBF; the rCBF measured during acute DBS at high frequency was then compared with those measured during DBS at low frequency and off (control) conditions. On the basis of neuroanatomical knowledge about the VC/VS and neuroimaging data on OCD, the authors predicted that acute DBS at this target would result in modulation of activity within the implicated frontal-basal ganglia-thalamic circuit. Data were analyzed using statistical parametric mapping. In a comparison of acute high-frequency DBS with control conditions, the authors found significant activation of the orbitofrontal cortex, anterior cingulate cortex, striatum, globus pallidus, and thalamus.

CONCLUSIONS

Acute DBS at the VC/VS target is associated with activation of the circuitry implicated in OCD. Further studies will be necessary to replicate these findings and to determine the neural effects associated with chronic VC/VS DBS. Moreover, additional data are needed to investigate whether pretreatment imaging profiles can be used to predict a patient's subsequent clinical response to chronic DBS.

Serotonin transporter promoter gain-of-function genotypes are linked to obsessive-compulsive disorder

A functional serotonin transporter promoter polymorphism, HTTLPR, alters the risk of disease as well as brain morphometry and function. Here, we show that HTTLPR is functionally triallelic. The L(G) allele, which is the L allele with a common G substitution, creates a functional AP2 transcription-factor binding site. Expression assays in 62 lymphoblastoid cell lines representing the six genotypes and in transfected raphe-derived cells showed codominant allele action and low, nearly equivalent expression for the S and L(G) alleles, accounting for more variation in HTT expression than previously recognized. The gain-of-function L(A)L(A) genotype was approximately twice as common in 169 whites with obsessive-compulsive disorder (OCD) than in 253 ethnically matched controls. We performed a replication study in 175 trios consisting of probands with OCD and their parents. The L(A) allele was twofold overtransmitted to the patients with OCD. The HTTLPR L(A)L(A) genotype exerts a moderate (1.8-fold) effect on risk of OCD, which crystallizes the evidence that the HTT gene has a role in OCD.

Serotonin transporter promoter gain-of-function genotypes are linked to obsessive-compulsive disorder

A functional serotonin transporter promoter polymorphism, HTTLPR, alters the risk of disease as well as brain morphometry and function. Here, we show that HTTLPR is functionally triallelic. The L(G) allele, which is the L allele with a common G substitution, creates a functional AP2 transcription-factor binding site. Expression assays in 62 lymphoblastoid cell lines representing the six genotypes and in transfected raphe-derived cells showed codominant allele action and low, nearly equivalent expression for the S and L(G) alleles, accounting for more variation in HTT expression than previously recognized. The gain-of-function L(A)L(A) genotype was approximately twice as common in 169 whites with obsessive-compulsive disorder (OCD) than in 253 ethnically matched controls. We performed a replication study in 175 trios consisting of probands with OCD and their parents. The L(A) allele was twofold overtransmitted to the patients with OCD. The HTTLPR L(A)L(A) genotype exerts a moderate (1.8-fold) effect on risk of OCD, which crystallizes the evidence that the HTT gene has a role in OCD.

Metabolic imaging of anterior capsular stimulation in refractory obsessive-compulsive disorder: a key role for the subgenual anterior cingulate and ventral striatum

High-frequency anterior capsular stimulation is a new, promising, and reversible neuromodulatory treatment in the research stage for patients with refractory obsessive-compulsive disorder (OCD). The mechanism of action is unknown but hypothesized to be secondary to interruption of the corticothalamostriatocortical circuit.

METHODS

(18)F-FDG PET was performed on 6 consecutive OCD patients preoperatively and after stimulation. The results were compared with those of 20 age- and sex-matched healthy volunteers by using both a standardized volume-of-interest-based approach for subcortical areas and statistical parametric mapping. Correlations were investigated with Yale-Brown Obsessive Compulsive Scale scores (Y-BOCS) and Hamilton Depression Rating Scale scores (HAM-D).

RESULTS

Chronic anterior capsular electrostimulation resulted in a further decrease of prefrontal metabolic activity, especially in the subgenual anterior cingulate (P < 0.001). Correlation analysis demonstrated that decreases in Y-BOCS and HAM-D with anterior capsular electrostimulation were inversely related to the metabolic activity changes in the left ventral striatum, left amygdala, and left hippocampus (P < 0.01). Preoperative resting metabolic activity in the subgenual anterior cingulate was predictive of therapeutic response (P = 0.001).

CONCLUSION

These observations provide evidence that the subgenual anterior cingulate and ventral striatum have a key role in the neuronal circuitry involved in the pathophysiology of OCD with associated major depression and in the neuromodulatory mechanism of anterior capsular stimulation.

The OCD collaborative genetics study: methods and sample description

Results from twin and family studies suggest that obsessive-compulsive disorder (OCD) may be transmitted in families but, to date, genes for the disorder have not been identified. The OCD Collaborative Genetics Study (OCGS) is a six-site collaborative genetic linkage study of OCD. Specimens and blinded clinical data will be made available through the National Institute of Mental Health (NIMH) cell repository. In this initial report, we describe the methods of the study and present clinical characteristics of affected individuals for researchers interested in this valuable resource for genetic studies of OCD. The project clinically evaluated and collected blood specimens from 238 families containing 299 OCD-affected sibling pairs and their parents, and additional affected relative pairs, for a genome-wide linkage study. Of the 999 individuals interviewed to date, 624 were diagnosed with "definite" OCD. The mean age of subjects was 36 years (range 7-95). The majority of affected individuals (66%) were female. The mean age at onset of obsessive-compulsive symptoms was 9.5 years. Specific mood disorders, anxiety disorders, eating disorders, and skin picking were more prevalent in female cases, whereas tics, Tourette disorder, and alcohol dependence were more prevalent in male cases. Compared to "definite" cases of OCD, "probable" cases (n = 82) had, on average, later age at onset of obsessive-compulsive symptoms, lower severity score, and fewer numbers of different categories of obsessions and compulsions, and they were less likely to have received treatment for their symptoms.