Transcranial direct current stimulation as early augmentation in adolescent obsessive compulsive disorder:A pilot proof-of-concept randomized control trial

BACKGROUND Transcranial direct current stimulation(tDCS)is proven to be safe in treating various neurological conditions in children and adolescents.It is also an effective method in the treatment of OCD in adults.AIM To assess the safety and efficacy of tDCS as an add-on therapy in drug-naive adolescents with OCD.METHODS We studied drug-naïve adolescents with OCD,using a Children’s Yale-Brown obsessive-compulsive scale(CY-BOCS)scale to assess their condition.Both active and sham groups were given fluoxetine,and we applied cathode and anode over the supplementary motor area and deltoid for 20 min in 10 sessions.Reassessment occurred at 2,6,and 12 wk using CY-BOCS.RESULTS Eighteen adolescents completed the study(10-active,8-sham group).CY-BOCS scores from baseline to 12 wk reduced significantly in both groups but change at baseline to 2 wk was significant in the active group only.The mean change at 2 wk was more in the active group(11.8±7.77 vs 5.25±2.22,P=0.056).Adverse effects between the groups were comparable.CONCLUSION tDCS is safe and well tolerated for the treatment of OCD in adolescents.However,there is a need for further studies with a larger sample population to confirm the effectiveness of tDCS as early augmentation in OCD in this population.

Understanding Behavioral Manifestations of Obsessive-Compulsive Disorder in People with Intellectual Disabilities—A Qualitative Study

Background: There is limited knowledge about obsessive-compulsive disorder (OCD) in people with intellectual disabilities (IDs). This paper describes the manifestation of compulsive behaviors associated with OCD at the behavioral level in people with ID in institutionalized settings. The aim was to gain nuanced insight into appropriate understanding and classification in this specific context, and derive implications for research and practice. Methods: Individual cases of people with ID (n = 7) were studied to assess compulsive symptoms through two days of on-site observation of the person with ID within the institution, guided group discussions (n = 28), and semi-structured interviews with key informants and caregivers of the person with ID (n = 20). Caregiver ratings of the compulsive behavior checklist were compiled. Data were analyzed using qualitative content analysis. Results: All forms of OCD were present. Characteristics of compulsive behaviors in people with ID at the behavioral level included less complex and more obvious compulsive acts, immediate responses, signs of tension, motor restlessness, facial expression changes, repetition, need for predictability, time-consuming behaviors, and aggressive reactions when these acts were interrupted. Some of the compulsive behaviors corresponded to the ICD-11 OCD code 6B20, and others to compulsions as a psychological symptom (MB23.4). Conclusions: OCD may manifest atypically at the behavioral level in people with ID, posing significant challenges for accurate classification due to symptom ambiguity. Follow-up differential diagnostic studies are needed to more accurately identify and differentiate OCD symptoms in people with ID. Further, disorder-specific guidelines for recognizing OCD in people with ID are needed for institutionalized settings without psychiatric-psychotherapeutic expertise.

Characterization of event-related potentials in obsessive compulsive disorder patients: Comparison with depression and generalized anxiety disorder patients

BACKGROUND： Study results of event-refated potential in obsessive compulsive disorder （OCD） remain controversial, potentially as a result of different instruments utilized and their differing technical characteristics. OBJECTIVE： To investigate the differences in several common event-related potentials, Le. contingent negative variations, P300, and mismatch negativity （MMN）, in OCD patients, depression patients, generalized anxiety disorder （GAD） patients, and healthy controls. DESIGN, TIME AND SETTING： A case-control study was performed in the Department of Electrophysiology, Shanghai Mental Health Center from May 2002 to December 2005. PARTICIPANTS： A total of 38 OCD patients, 20 depression patients, and 18 GAD patients, who were diagnosed according to the criteria of Chinese Classification of Mental Disorders （Version 3）, formulated by the Chinese Psychiatry Association, were selected from the Outpatient Department of Shanghai Mental Health Center. Patients with two or more the above diseases were excluded. In addition, 28 healthy people, gender and age matched, were selected as controls. METHODS： Contingent negative variations, P300, and MMN were recorded by a Nicolet Spirit Instrument. All electrodes were attached at Cz according to the Intemationa11020 system, with the mastoid leads as reference and Fpz as ground. MAIN OUTCOME MEASURES： Amplitude and latency of contingent negative variations, P300, and MMN. RESULTS： The contingent negative variations, P300, and MMN were different （P 〈 0.01）. OCD patients showed an increased MI amplitude compared with controls, depression, and GAD patients （P 〈 0.01）. Target P300 amplitudes were significantly lower in OCD, depression, and GAD patients compared with controls （P 〈 0.01）. Moreover, N2 latency and latency of MMN were prolonged in OCD and depression groups compared with controls （P 〈 0.05）. CONCLUSION： Event-related potentials were different in depression, GAD, and OCD patients and healthy controls. In particular, OCD patients exhibited unique characteristics.

Cognitive-behavioural therapy for obsessive-compulsive disorder co-occurring with psychosis: Systematic review of evidence

AIM To review available evidence on the use of cognitive behavioural therapy(CBT) for treating obsessive compulsive disorder co-occurring with psychosis.METHODS In this paper we present a detailed and comprehensive review of the current literature focusing on CBT treatment of obsessive compulsive disorder(OCD) co-occurring with schizophrenia or schizoaffective disorder. We identified relevant literature published between 2001 and May 2016 through MEDLINE/PubM ed search using as search string("obsessive compulsive disorders" or "obsessive compulsive symptoms") and("schizophrenia" or "schizoaffective disorder" or "psychosis") and("cognitive behavioural therapy"). Other citations of interest were further identified from references reported in the accessed articles. The search was limited to studies written in English and carried out in adult patients. A total of 9 studies, 8 case reports and 1 case series, were found.RESULTS The reviewed evidence indicates that CBT is:(1) safe, i.e., does not worsen psychotic symptoms;(2) well accepted, with a discontinuation rate quite similar to that reported for patients with OCD without psychosis comorbidity;(3) effective, with a symptom reduction quite similar to that reported for patients with OCD without psychosis and for SRIs treatment of OCD cooccurring with psychosis; and(4) effective in patients with OCD induced by second-generation antipsychotic as well as in patients with OCD not induced by secondgeneration antipsychotic. Alcohol/substance use disorder comorbidity and OCD onset preceding that of SCH/SA was predictors of poor outcome. These results are derived only by additional studies with adequate sample size.CONCLUSION Our results support the use of CBT for OCD in patients with psychosis.

Attribution retraining group therapy for outpatients with major depression disorder,generalized anxiety disorder,and obsessive-compulsive disorder:a pilot study

The aim of this present study is to examine the efficacy of attribution retraining group therapy （ARGT） and to compare the responses of outpatients with major depression disorder （MDD）, generalized anxiety disorder （GAD） and obsessive-compulsive disorder （OCD）. We carried out a prospective uncontrolled intervention study with a 8-weeks of ARGT on sixty three outpatients with MDD, GAD or OCD. Hamilton rating scale for depression, Hamilton rating scale for anxiety, Yale-Brown obsessive-compulsive scale, attribution style questionnaire, self-esteem scale, index of well-being, and social disability screening schedule were administered before and after treatment. Significant improvement in symptoms and psychological and social functions from pre- to posttreatment occurred for all participants. The changes favored MDD patients. Our study suggested that ARGT may improve the symptoms and psychological-social functions of MDD, GAD, and OCD patients. MDD patients showed the best response.

Psychic euosmia and obsessive compulsive personality disorder

Patients with obsessive compulsive personality disorder(OCPD) often refer to a prompt mood improvement upon encountering good scents in general, or fresh laundry borax on their clothes, pillows or home settings. The Authors propose the new term psychic euosmia in the mean of an overstated psychological predisposition for a real pleasant smell that elicits an immediate sense of pleasure, order and calm. The prompt reactions to a pleasant odor might be explained by the involvement of rhinencephalon and its proximity to mood-related limbic circuits, which bypass the cognitive awareness. Cleanliness may not preclude a subject to enjoy a good smell, even if we are representing smells that resemble freshness, in other words order. A potentially even more important argument is given by the continuum of personality disorders and their variability. Not all personality characteristics led to disturbed behaviors. In evolutionary perspectives having the ability to differentiate between unpleasant and pleasant odors should have made the difference in surviving. On the other hand, psychic euosmia could be considered a normal reaction, but in our clinical experience it is over-represented among OCPD subjects with marked orderliness and disgust. Therefore, detecting psychic euosmia might vicariously confirm the relevance of disgust as a cognitive driver of OCPD. Hereby we support research to characterize psychic euosmia as a feature of orderliness and cleanliness for OCPD.

Obsessive-compulsive disorder:Evidence-based treatments and future directions for research

Over the past three decades, obsessive-compulsive disorder(OCD) has moved from an almost untreatable,life-long psychiatric disorder to a highly manageable one. This is a very welcome change to the 1%-3% of children and adults with this disorder as, thanks to advances in both pharmacological and psychological therapies, prognosis for those afflicted with OCD is quite good in the long term, even though most have comorbid disorders that are also problematic. We still have far to go, however, until OCD can be described as either easily treatable or the effective treatments are widely known about among clinicians. This review focuses on the current state of the art in treatment for OCD and where we still are coming up short in our work as a scientific community. For example, while the impact of medications is quite strong for adults in reducing OCD symptoms, current drugs are only somewhat effective for children. In addition, there are unacceptably high relapse rates across both populations when treated with pharmacological alone. Even in the cognitive-behavioral treatments, which show higher effect sizes and lower relapse rates than drug therapies, drop-out rates are at a quarter of those who begin treatment. This means a sizable portion of the OCD population who do obtain effective treatments(which appears to be only a portion of the overall population) are not effectively treated.Suggestions for future avenues of research are also presented. These are primarily focused on(1) increased dissemination of effective therapies;(2) augmentation of treatments for those with residual symptoms, both for psychotherapy and pharmacotherapy; and(3) the impact of comorbid disorders on treatment outcome.

Anterior limb lesions in bilateral internal capsules and memory function in patients with refractory obsessive-compulsive disorder

BACKGROUND： Previous studies have shown that lesions in the anterior limb of the internal capsule contribute to obsessive-compulsive symptoms in patients with refractory obsessive-compulsive disorder （OCD）. However, few reports have addressed the effects of lesions in the anterior limb of the internal capsule on cognition, learning, and memory functions in patients with refractory OCD. OBJECTIVE： To investigate the degree of damage to memory tasks in refractory OCD patients following lesions to the anterior limb of the internal capsule. DESIGN, TIME AND SETTING： A case-controlled, observational study was performed at the Department of Functional Neurosurgery, Ruijin Hospital, Shanghai Jiao-Tong University, China from May 2007 to March 2008. PARTICIPANTS： A total of 10 refractory OCD patients were admitted to the Department of Functional Neurosurgery, Ruijin Hospital, Shanghai Jiao-Tong University, China from May 2007 to March 2008 and were recruited for this study. The OCD patients were of equal gender, with an average age of （25.1 ± 9.6） years. An additional 10 healthy volunteers were enrolled from a community of Shanghai City as controls; they were of equal gender and aged （25.1 ± 8.6） years. METHODS： A total of 10 refractory OCD patients were subjected to lesions in the anterior limbs of the bilateral internal capsules. Wechsler Memory Scale-Chinese Revision （WMS-CR, as a task of explicit memory） and the Nissen Version （serial reaction time task） software （SRTT, as a task of implicit memory） were applied to determine memory functions and learning performance in pre- and post-operative OCD patients and controls. MAIN OUTCOME MEASURES： WMS scores, reaction time in SRTT, and Yale-Brown obsessive compulsive scale scores were measured in pre- and post-operative OCD patients and controls. RESULTS： Compared to controls, the pre-operative OCD patients exhibited reduced memory task scores （P = 0.005）, whereas scores for reciting numbers of backwards digits were greater （P = 0.000）. Figure recall and associative memory were less in OCD patients at 1 week following surgery than in the pre-operative OCD patients （P = 0.042, P = 0.002, respectively）. Reaction time in implicit SRTT was significantly longer in pre-operative OCD patients compared with controls and post-operative OCD patients （P = 0.01, P = 0.03, respectively）. These results suggested ameliorated SRTT following neurosurgery. Yale-Brown Obsessive Compulsive Scale results revealed significantly improved OCD following lesions in the internal capsule （P = 0.04）. Some post-operative OCD patients suffered from deficits in short-term memory and implicit memory. CONCLUSION： Lesions in anterior limbs of bilateral internal capsules improve obsessive- compulsive symptoms and implicit memory in OCD patients, but result in aggravated short-term memory deficits.

THE COMPARATIVE STUDY OF EVENT RELATED POTENTIALSIN PATIENTS WITH OBSESSIVE COMPULSIVE DISORDER,DEPRESSION AND ANXIETY

Objective:To investigate the variations of contingent negative varisations(CNV),P300 and mismatch negativity (MMN) in patients with obsessive compulsive disorder(OCD),depressiopn and anxiety.MEthods:Event-related potentials CNV,P300 and MMN were recorded in 31 patients with OCD by Nicolet SPirit Instrument,and were compared with that of 20 depression controls(DC) and 17 anxiety controls(AC)and 28 normal controls(NC),Results:A significant difference of CNV among 4 sulbject groups was found in both post-imperative negative variation(PINV) and amplitudes(M1)(P<0.01)(emergence of PINV were 45%),60%,35%,and 4% in OCD,DC,AC and NC groups respectively),Compared with NC group,DC and AC groups showed decreased M1 amplitude(P<0.01).A significant difference of P300 among 4 groups was found in both latencies(Cz/N2) and P3 and nontarget-P2 amplitudes(P<0.05-0.01),The delayed MMN latencies of OCD and DC were similar to that of P300 changes,Conclusions:CNV,P300 and MMN are useful tools for assessing the brain malfunction of OCD,DC and AC,and its clinical application are suggested.The characteristics ERPs of those patients might be useful indexes in distinguishing OCD from DC and AC patients.

Intrusive Thoughts and Executive Functions in Obsessive Compulsive Disorder

Objectives: Our aim was to compare the effects of an unwanted intrusive thought on executive function in a group of people with Obsessive Compulsive Disorder (OCD) and in a healthy group. Method: The Behavior Rating Inventory of Executive Function Adult (BRIEF-A) was used to measure executive dysfunction in everyday life in people with OCD. The study participants underwent either an intrusive thought induction or neutral thought induction prior to the administration of three computer-based tests of executive function. Results: The BRIEF-A results confirmed the impairment of executive function in everyday life for patients with OCD. In the number-letter task, patients with OCD displayed a longer reaction time (relative to the controls). There were no intergroup differences in the local-global task. In the go/no-go task, there was a significant impairment (p = 0.03) in the OCD group (with more commission errors than controls). There was a non-significant trend towards an effect of thought induction in both groups in the number-letter task. However, intrusive thought induction did not have a greater effect than neutral thought induction on the OCD group in any of the tasks. Conclusions: Intrusive thought induction has no effect on executive function in the two groups. The two groups differed with regard to two executive tasks.

Validation of Symptom Dimensions and Sub-Type Responses in Cognitive Behavioral Therapy in Obsessive Compulsive Disorder: A Systemic Review and Meta-Analysis

Background: Obsessive-compulsive disorder (OCD) is a clinically heterogeneous condition without a conclusivesubtype dimension. This study will focus on the meta-analysis of the clinical responses of OCD subtypes to cognitivebehavioral therapy (CBT), which might clarify this issue. Methods: We performed a systematic search and ameta-analysis for the studies of OCD subtypes and the response to CBT in PubMed, ScienceDirect, Embase, Webof Science, and Scopus databases. The selective criteria were the OCD without significant medical or psychiatricco-morbidities and pre-and post-treatment changes in scores of OCD dimension. In addition, different subtypesof OCD in symptom dimensions, such as symmetry, contamination, unacceptable thoughts, and hoarding, werecompared to find the most significant subtype using the treatment response parameters by CBT. After limitedselection, four studies and 479 OCD subjects were enrolled. The meta-analysis was performed by Review Manager5.4, and only significant results were reported. Results: Among the OCD subtypes, the meta-analysis favors thehoarding subtype with poorer responses to CBT than symmetry, contamination, and unacceptable thoughts.The meta-analysis results were negative mean differences, significant tests for overall effect, and limited heterogeneitiesin the random effects model. In addition, the results were more significant when the hoarding subtypewas compared with non-hoarding subtypes. Conclusion: The hoarding subtype might be the most significantrepresentative subtype of OCD symptom dimension under the impression of unfavorable clinical response toCBT. However, future studies with more treatment parameters will be warranted to confirm this finding.

Broader Role for Antipsychotics in the Treatment of Obsessive Compulsive Disorder and Schizophrenia—A Malaysian Case Series

Obsessive compulsive disorder (OCD) and schizophrenia have been considered to be variants of the same disorder. At the advent of psychiatry, there was a distinction between neurotic, mood disorders and psychotic disorders. As perceptions and thoughts evolve in this dynamic field, there has been a paradigm shift in the way these disorders are being perceived. Of particular interest is that concerning OCD and schizophrenia. In a much anticipated and very welcomed move, DSM V has now included delusional beliefs as a specifier of OCD. However the much spoken about schizo- obsessive syndrome is yet to be explored and addressed. Recurrent and intrusive thoughts, impulses and images are key experiences seen in OCD. How we differentiate these vivid images from visual hallucination is a question yet to be answered. The following case series is an example of how difficult the boundaries between severe OCD and schizophrenia can be, and the promising usage of atypical antipsychotic in controlling obsessive compulsive symptoms. Whether untreated OCD is a significant prodromal symptom of schizophrenia, a subtype of schizophrenia or an initial indicator of various syndromes, remains to be seen, depending on environmental effects on the neuroplasticity of the mind and brain. The cases discussed will highlight the role of antipsychotics in patients diagnosed as having OCD, and gives strength to the idea that perhaps antipsychotics should be used more liberally in the treatment of OCD in schizophrenia. Here, we present a case series to show the use of atypical antipsychotics as monotherapy or augmenter in quelling obsessive-compulsive symptoms in patients who fulfilled the DSM V criteria for both schizophrenia and OCD. The efficacy of antipsychotics in reducing OCD symptoms in psychotic patients, as shown in this case series, contributes to the body of evidence that OCD and schizophrenia are really spectrum disorders with a common denominator. It is hoped that this exciting finding will lead to a paradigm shift in the usage of antipsychotics in OCD and eventually change how this disease is viewed and treated.

Neuropsychological and Neurological Deficits in Obsessive-Compulsive Disorder: The Role of Comorbid Depression

Past research has found a high prevalence of neuropsychological deficits and neurological soft signs in patients with obsessive-compulsive disorder (OCD). A close relationship between OCD and depression has also been indicated in the literature. However, many aspects of this association remain unclear. In this study we compared neuropsychological functioning and neurological soft signs of 46 OCD patients who were off psychotropic medication (21 with significant depressive symptoms and 25 without) with 25 non-patient comparison subjects. The patients were matched to the comparison group with regard to age, sex, education, marital status and handedness. There were significant differences between OCD patients and the non-patient comparison group on neuropsychological functioning but not on neurological soft signs. As far as working memory concerns there was a significant difference between the OCD depressed and non-depressed groups. But we found no evidence that the neuropsychological functions such as cognitive flexibility, problem solving and spatial perception in OCD to be attributable to comorbid depression. The pattern of neuropsychological deficits in this sample of OCD patients is suggestive of orbito-frontal as well as dorsolateral prefrontal cortical dysfunction.

Review of source-monitoring processes in obsessive-compulsive disorder

Obsessive-compulsive disorder(OCD)is a severe mental illness characterized by persistent,intrusive and distressing obsessions and/or compulsions.Such symptoms have been conceptualized as resulting from a failure in sourcemonitoring processes,suggesting that patients with OCD fail to distinguish actions they perform from those they just imagine doing.In this study,we aimed to provide an updated and exhaustive review of the literature examining the relationship between source-monitoring and OCD.A systematic search in the literature through January 2019 allowed us to identify 13 relevant publications investigating source-monitoring abilities in patients with OCD or participants with subclinical compulsive symptoms.Most of the retrieved studies did not report any source-monitoring deficits in clinical and subclinical subjects compared with healthy volunteers.However,most of the studies reported that patients with OCD and subclinical subjects displayed reduced confidence in source-monitoring judgments or global cognitive confidence compared to controls.The present review highlighted some methodological and statistical limitations.Consequently,further studies are needed to explore source monitoring with regard to the subcategories of OCD symptoms(i.e.,symmetryordering,contamination-washing,hoarding,aggressive obsession-checking,sexual-religious thoughts)and to clarify the relationship between sourcemonitoring subtypes(i.e.,reality or internal source-monitoring)and confidence in these populations.

Validation of a Classification System for Obsessive-Compulsive and Related Disorders Based on DSM-5

The purpose of this study was to examine whether a broad?obsessive-compulsive and related disorders model, which consisted of obsessive-compulsive, hoarding disorder, body dysmorphic, trichotillomania and pathological skin picking, displayed sufficient data fit. On the other hand, we examined whether a reduced obsessive-compulsive and related disorders symptoms model consisting of above mentioned disorders demonstrated superior fit or not. To test the factor structure validity of the classification system of obsessive-compulsive spectrum disorders, we used Confirmatory Factor Analyses (CFA). Result of factor structure analysis revealed and supported an OCSD symptoms dimension that included obsessive-compulsive, hoarding disorder, body dysmorphic, trichotillomania, and pathological skin picking symptoms. Also, results of this study supported?the DSM-5 changes.

Developing and Evaluating the Effectiveness of the Behavioral-Cognitive-Metacognitive Intervention on the Severity of Obsessive- Compulsive Disorder’s Symptoms

Obsessive-compulsive disorder is a disorder which is resistant to the existing treatments and to compensate this defect, it is necessary to design and search for the new treatments. This study aims to develop and evaluate the effectiveness of the behavioral-cognitive-metacognitive intervention on the symptoms of obsessive-compulsive disorder. In order to achieve objectives of the study, after developing the behavioral-cognitive-metacognitive intervention, it was evaluated in a single-subject procedure. OCI-R scores at baseline were obtained by following the treatment on 3 individuals. The study was a single-subject research and the data were analyzed by drawing the graph. Graph drawing results showed that the behavioral-cognitive-metacognitive intervention reduced the symptoms of obsessive-compulsive disorder (OCD), and reduction of OCD symptoms was also clinically significant. As the intervention of the present study is multi-dimensional and takes into account all the three behavioral, cognitive and metacognitive aspects and considers them interdependent and not apart or contradictory, it is considered as a new intervention.

Obsessive-compulsive disorder in disguise—Case report

Obsessive-compulsive disorder (OCD) may mimic other minor and major psychiatric disorders or symptoms. Psychomotor disturbances may also be seen in OCD. Symptoms and complaints could be misinterpreted. Differential diagnostic assessments would be difficult either if the person has OCD or another diagnostic entity with OCD related symptoms. If clinicians in residential or outpatient settings do not realize this, the patients may suffer from inadvertent pharmacological treatment efforts, to no avail. A representative case of the former is presented. Withdrawal of all psychotropic medications cold turkey did not increase symptom load during the following weeks, indicating little benefit from medications. Because of continued complaints from the patient, psychotropic medications were gradually reintroduced, without any improvement. OCD patients may not be helped by extensive use of psychotropics and doctors responsible for them should employ other methods of reducing OCD symptoms than lumping together diverse psychotropics. There is evidence for the value of intensive cognitive behaviour therapy, but also for addressing the social conditions of the patients.

The Obsessive Compulsive Disorder Symptoms after the Successful Treatment of the Pineal Germinoma： A Case Report

We report here, a young male patients referred with ＂Obsessive Compulsive Disorder＂ symptoms which emerged after the successful treatment of pineal germinoma. OCD （obsessive-compulsive disorder） is a frequent, chronic, and clinically disorder which may presents in several neurologic disorders, especially occurs, in early adult life. Essential features of OCD are obsessional thoughts, compulsive acts as the ritualistic behavior, anxiety, and specific cognitive impairments. The cause of obsessive-compulsive disorder isn＇t fully understood. One of the many theories of the pathophysioiogy about to OCD is includes with hyperactivity in certain subcortical and cortical regions of brain also, dysfunction of the cortico-striatal circuits, particularly implicated in orbitofrontal cortices and basal ganglions. Additionally, pineal gland functioning is remarkable for the mental health disorders, particularly in OCD. On the basis of the investigations to present case report, we discussed the probable reasons of OCD symptoms, emphasizing the role of pathophysiology including the cortico subcortical pathways in genesis of the symptoms.

Animal Models of Obsessive-Compulsive Disorder: Strain Differences

Obsessive-compulsive disorder (OCD) is characterized by obsessions (intrusive thoughts, images etc.) and compulsions (repetitive, stereotyped and perseverant acts). Animal models of OCD are specifically devoted to simulating compulsive features of the disorder. In OCD, compulsive behaviors are recognized as repetitive and maladaptive and symptoms relief can be experienced due to treatment with selective serotonin reuptake inhibitors. Many animal models of OCD are provided with some degree of validity. Genetically based differences in behavior in animal models of OCD are of great value, given that human OCD is reported to involve genetic factors. Some animal models of OCD were already used in studies for the evaluation of strain differences. These works were explored in the present review.