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Dive into the research topics where Kazuhiro Tajima-Pozo is active.

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Featured researches published by Kazuhiro Tajima-Pozo.


Journal of Affective Disorders | 2012

Microstructural white matter damage at orbitofrontal areas in borderline personality disorder.

José Luis Carrasco; Kazuhiro Tajima-Pozo; Marina Díaz-Marsá; Ana Casado; Juan José López-Ibor; Juan Arrazola; Miguel Yus

OBJECTIVES Prefrontal cortex plays a major role in the modulation of behaviors and emotions through regulation of both information processing and impulse control. Low prefrontal function in borderline personality disorder (BPD) has been consistently reported by a number of studies using neuropsychological assessments and functional neuroimaging techniques. To further explore this findings, this study aimed to investigate microstructural damage of prefrontal white matter tracts in subjects with BPD by using the novel, voxel-based approach, tract-based spatial statistics (TBSS). METHODS A Diffusion Tensor Image (DTI) study was performed in 28 patients with DSM-IV BPD (13 males and 15 females) and in 26 healthy control subjects. Voxel wise analysis was performed using TBSS (diffusion toolbox of FSL - functional MRI Software Library) to localize regions of white matter showing significant changes of fractional anisotropy (FA). RESULTS TBSS analysis revealed a statistically significant decrease of FA in the genu and rostral areas of the corpus callosum (p<0.005), as well as in left and right prefrontal white matter fasciculi (p<0.002) in BPD participants compared with controls. White matter abnormalities were not correlated with age, neurological symptoms or comorbid ADHD. CONCLUSIONS Despite the reduced sample size, the results are in line with previous findings on reduced orbitofrontal functions in BPD with prominent affective-depressive feature and suggest that emotional and behavioral symptoms of BPD patients might be associated to damage at the connectivity tracts in these brain areas.


Journal of Attention Disorders | 2016

Amygdala Abnormalities in Adults With ADHD

Kazuhiro Tajima-Pozo; Miguel Yus; Gonzalo Ruiz-Manrique; Adrian Lewczuk; Juan Arrazola; Francisco Montañes-Rada

Objective: The suggested neurobiological bases of ADHD focus on the amygdala as a center of emotions processing. Therefore, we hypothesize that patients with ADHD will show an irregular pattern of emotional-related activity of the amygdala region as well as some structural abnormalities. Method: Nine adult patients with ADHD and nine group-matched healthy volunteers were studied using a 1.5-T magnetic resonance imaging (MRI) scanner. Morphometric measurements were obtained manually, and they were later processed and compared. Absolute volumes of several structures and nuclei were calculated with FSL-FIRST. For the functional magnetic resonance examination, a set of two paradigms was prepared, using a block design, incorporating images of the International Affective Picture System (IAPS). The patients were unmedicated at the time of the MRI scan. Results: Negative correlation was found between the right amygdala volume and Barrat’s impulsivity scores (r = −.756, p = .018). The age of patients did not turn out to be a significant factor. No significantly higher activation areas were found in patients with unpleasant content images. For the left amygdala, an Region Of Interest (ROI)-based analysis showed moderately higher level of activation in the patients than in the controls with pleasant content images. Conclusion: Patients with ADHD tend to have smaller amygdala volumes. ADHD patients presented less activation in the area of the left frontal pole than the controls. There was no amygdala activation stated when presenting the pleasant images. Whereas bigger activation of the left amygdala was found in patients while presenting them unpleasant images. These results might suggest that lower emotional processing and less control of impulsivity is associated with dysfunctional amygdala in ADHD patients.


Acta Neuropsychiatrica | 2015

Correlation between amygdala volume and impulsivity in adults with attention-deficit hyperactivity disorder.

Kazuhiro Tajima-Pozo; Gonzalo Ruiz-Manrique; Miguel Yus; Juan Arrazola; Francisco Montañes-Rada

Background Attention-deficit hyperactivity disorder (ADHD) is a chronic neurobiological disorder with childhood onset and persistence through adolescence and adulthood. ADHD patients frequently show exaggerated emotional responses. The amygdala plays an important role in emotion processing and in the activation of the frontal lobe. We hypothesised that smaller amygdala volumes in ADHD patients would be associated with less control of impulsivity and emotional instability. Methods We studied nine adult patients with ADHD and nine group-matched healthy volunteers using a 1.5 T magnetic resonance imaging scanner. We manually obtained morphometric measurements, which were later processed and compared. Results Significant negative correlation between the right amygdala volume and Barratt’s impulsivity scores was observed (r=−0.756, p=0.018). No correlation was found between impulsivity scores and the volume of the left amygdala. Age was not found to be a contributor of the results. Conclusions Smaller amygdala volumes have been observed in patients with ADHD. Our results suggest that greater emotional processing and less control of impulsivity are associated with smaller amygdala volumes in ADHD patients. Furthermore, the right amygdala would play a bigger role in impulsivity and behaviour control than the left amygdala. Further studies involving larger samples of adult patients with ADHD and using multimodal designs are needed.


Case Reports | 2011

Practicing exorcism in schizophrenia

Kazuhiro Tajima-Pozo; Diana Zambrano-Enriquez; Laura de Anta; María Dolores Moron; José Luis Carrasco; Juan José López-Ibor; Marina Díaz-Marsá

Historically, many cases of demonic possession have masked major psychiatric disorder. Our aim is to increase awareness that symptoms of schizophrenia are still being classified as demonic possession by priests today. We report the case of a 28-year-old patient who had been diagnosed 5 years previously with paranoid schizophrenia (treated with clozapine, risperidone, ziprasidone and onlanzapine without a complete response) and was also receiving treatment in a first episode psychosis unit in Spain. The patient was led to believe by priests that her psychotic symptoms were due to the presence of a demon. This was surprising because some of the priests were from the Madrid archdiocese and knew the clinical situation of the patient; however, they believed that she was suffering from demonic possession, and she underwent multiple exorcisms, disrupting response to clinical treatment. Patient insight is an important factor in response to treatment, so religious professionals should encourage appropriate psychiatric treatment and learn about mental illnesses.


Indian Journal of Psychological Medicine | 2015

Correlation between personality traits and testosterone concentrations in healthy population

Kazuhiro Tajima-Pozo; Camila Bayón; Marina Díaz-Marsá; José Luis Carrasco

Objective: High plasma testosterone levels have been associated with aggression, sexual behaviour and social status. The aim of this paper was to study the correlation between basal plasma testosterone levels and personality variables in healthy participants. Materials and Methods: Fifty-four participants were randomly enrolled into this study. Basal plasma testosterone levels were measured between 8:30 am and 10 am. After 24 hours of blood drawing, each subject completed personality questionnaires. Results: Positive correlation between basal plasma testosterone levels and anti-social personality traits in both genders was observed (r = 0.336 and P < 0.018). Also, a positive correlation was observed between basal plasmatestosterone levels and criminal thinking traits (r = 0. 376, P < 0.05) and Millon compulsive (r = 0.386, P < 0.010) in both genders. In female participants, a positive correlation between basal plasmatestosterone levels and psychoticism (r = 0. 25, P < 0.019) and Cloninger AUTO TCI (r = 0.507, P < 0.004) was observed. In males participants positive correlation between baseline plasmatic Testosterone levels and Millon Antisocial trait (r = 0. 544, P < 0.19) and Millon Hypomania trait (r = 0. 485, P < 0.41) and Millon Drug Abuse trait (r = 0.632, P < 0.05) was reported. Conclusion: Our results suggest gender differences in clinical and personality variables related with basal plasma testosterone level. In men, high plasma testosterone levels were associated with clinical traits, substance abuse and hypomania. Women with higher basal testosterone levels showed higher scores on personality self-direction traits.


Cardiovascular endocrinology | 2015

Atypical antipsychotics and metabolic syndrome

Abigail Perez Rodriguez; Kazuhiro Tajima-Pozo; Adrian Lewczuk; Francisco Montañes-Rada

Atypical antipsychotics have become the gold standard and the first treatment option for mental illness in recent years. However, despite all the benefits provided by these drugs, a growing collection of case reports and clinical trials describing metabolic complications and body weight gain have been reported. Among atypical antipsychotic drugs, olanzapine and clozapine appear to have the highest tendency to disturb glucose metabolism compared with the other antipsychotic drugs available on the market.


F1000Research | 2014

Case Report: "ADHD Trainer": the mobile application that enhances cognitive skills in ADHD patients

Gonzalo Ruiz-Manrique; Kazuhiro Tajima-Pozo; Francisco Montañes-Rada

We report the case of a 10 year old patient diagnosed with attention deficit hyperactivity disorder (ADHD) and comorbid video game addiction, who was treated with medication combined with a novel cognitive training method based on video games called TCT method. A great risk of developing video game or internet addiction has been reported in children, especially in children with ADHD. Despite this risk, we hypothesize that the good use of these new technologies might be useful to develop new methods of cognitive training. The cognitive areas in which a greater improvement was observed through the use of video games were visuospatial working memory and fine motor skills. TCT method is a cognitive training method that enhances cognitive skills such as attention, working memory, processing speed, calculation ability, reasoning, and visuomotor coordination. The purpose of reviewing this case is to highlight that regular cognitive computerized training in ADHD patients may improve some of their cognitive symptoms and might be helpful for treating video game addiction.


Endocrinología y Nutrición | 2013

Aportaciones de los tests de supresión de cortisol al conocimiento de los trastornos psiquiátricos: revisión narrativa de la literatura

Kazuhiro Tajima-Pozo; Ana Montes-Montero; Itziar Güemes; Sara González-Vives; Marina Díaz-Marsá; José Luis Carrasco

Activity of the hypothalamic-pituitary-adrenal axis had been studied for the past half century, when some researchers noted that some patients with Cushings syndrome and severe mood disorders had high baseline cortisol levels, which resulted in an inhibited response in the 1mg dexamethasone suppression test. Altered dexamethasone suppression test results were subsequently found in many psychiatric diseases, including anorexia nervosa, obsessive-compulsive disorder, degenerative dementia, bipolar disorders, and schizophrenia. The relationship between high baseline cortisol levels and stress has also been studied. Some researches on the genesis of borderline personality disorder focused on traumatic childhood backgrounds. Other investigations aimed at elucidating the relationship between traumatic backgrounds and some psychiatric disorders noted that patients with post-traumatic stress disorder and borderline personality disorder showed an enhanced cortisol suppression with low cortisol doses (0.5 mg). Recent studies showed that use of an ultra-low dose of cortisol during the dexamethasone suppression test may be helpful for detecting disorders with hyperactivity of the hypothalamic-pituitary-adrenal axis. Recent advances in neuroimaging support the existence of hyperactivity of the hypothalamic-pituitary-adrenal axis in patients with borderline personality disorder, relating a decreased pituitary gland volume to major traumatic backgrounds and suicidal attempts. The purpose of this paper is to make a narrative review of research using dexamethasone suppression test in psychiatric disorders, in order to ascertain its value as a supplemental diagnostic test or as a prognostic marker.


Case Reports | 2010

Otitis and autism spectrum disorders.

Kazuhiro Tajima-Pozo; Diana Zambrano-Enriquez; Laura de Anta; Julie Zelmanova; José Luis de Dios de Vega; Juan José López-Ibor

The case of a 5-year-old child diagnosed as having pervasive developmental disorder (PDD), autistic type, from age 1 is reported. After surgery of vegetation in middle ear for repetitive otitis, the child presented an improvement in autistic behaviours, previously expressed as impaired social interactions, qualitative abnormalities in communication, a marked delay in language development, echolalia, stereotypies and self-aggressive behaviours. The aim of this paper is to bring attention to occurrences of misdiagnosis of PDD, which can occur when an adequate screening of the autistic syndrome is not realised. The result of the surgery was an improvement in autistic behaviours, despite the persistence of less severe autistic traits that may be more closely related to Asperger’s syndrome.


Case Reports | 2014

Treating enuresis in a patient with ADHD: application of a novel behavioural modification therapy

Kazuhiro Tajima-Pozo; Gonzalo Ruiz-Manrique; Francisco Montañes

We report the case of a 6-year-old patient diagnosed with attention-deficit hyperactivity disorder (ADHD) and comorbid enuresis disorder, who was treated with methylphenidate for the past 3 months and a novel behavioural modification therapy by using an application called ‘Enuresis Trainer’. This therapeutic application is basically an interactive ‘Bedwetting Calendar’, based on traditional cognitive behavioural modification therapies and positive reinforcement systems. Enuresis is defined as the failure of voluntary control of the urethral sphincter. The prevalence of enuresis is 15–20% in the child population; however, children with ADHD had a 2.7 times higher incidence of nocturnal enuresis. Bedwetting is a common cause of isolation in children as well as loss of self-esteem and other psychological distress for the child and the family.

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José Luis Carrasco

Complutense University of Madrid

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Marina Díaz-Marsá

Complutense University of Madrid

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Juan José López-Ibor

Complutense University of Madrid

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Itziar Güemes

Complutense University of Madrid

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Miguel Yus

University of Alicante

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Adrian Lewczuk

Medical University of Warsaw

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