Arash Javanbakht

Gender dimorphism in the DAT1 − 67 T-allele homozygosity and predisposition to bipolar disorder

Linkage and association studies implicate the dopamine transporter gene (DAT1) in the etiopathophysiology of bipolar disorder. We have recently reported the association between the DAT1 core promoter -67A/T polymorphism and this disorder in a sample of Iranian patients. For the first time, these data support sex dimorphism in the homozygosity for the -67 T-allele between male and female affected cases. The present study was undertaken with a larger sample size of cases (N=240) and controls (N=213) to determine whether there is consistent difference between male and female patients and homozygosity for this allele. The results confirm and strengthen our preliminary observation that homozygosity for the T-allele is a predisposing factor in male patients, but not in females (chi2=8.825, df=1, p=0.003). Moreover, Hardy-Weinberg disequilibrium was observed in the female cases studied (chi2=12.9, df=1, p=0.0003), which may reflect the underlying biology. These findings imply gender dimorphism with respect to the DAT1 -67 alleles and susceptibility to disease.

A Neural Network Model for Transference and Repetition Compulsion Based on Pattern Completion

In recent years because of the fascinating growth of the body of neuroscientific knowledge, psychoanalytic scientists have worked on models for the neurological substrates of key psychoanalytic concepts. Transference is an important example. In this article, the psychological process of transference is described, employing the neurological function of pattern completion in hippocampal and thalamo-cortical pathways. Similarly, repetition compulsion is seen as another type of such neurological function; however, it is understood as an attempt for mastery of the unknown, rather than simply for mastery of past experiences and perceptions. Based on this suggested model of neurological function, the myth of the psychoanalyst as blank screen is seen as impossible and ineffective, based on neurofunctional understandings of neuropsychological process. The mutative effect of psychoanalytic therapy, correcting patterns of pathological relatedness, is described briefly from conscious and unconscious perspectives. While cognitive understanding (insight) helps to modify transferentially restored, maladaptive patterns of relatedness, the development of more adaptive patterns is also contingent upon an affective experience (working through), which alters the neurological substrates of unconscious, pathological affective patterns and their neurological functional correlates.

A Neural Network Model for Schemas Based On Pattern Completion

Abstract Recent developments in neuroscience have provided us with a wealth of the basic knowledge and tools which are required for neurobiological understanding of the psychological concepts. This advantage enables contemporary scientists to suggest and test brain models for psychological concepts, theories, and methods. Considering the current dominance of biological ideas in psychiatry and psychology, such models are essential in confirmation of the psychological theories of mind. In this article a brain model for schemas as essential to cognitive theory is proposed. Schemas are seen as patterns which are recognized and memorized through the training phase of an autoassociative neural network. Then, these patterns are used to complete ambiguous aspects of future experiences through thalamo and hippocampal-cortical pathways. In relation to the self or the outside world when a pattern with unknown, noisy, or vague aspects is encountered, those aspects are completed by the principal components of previously learned patterns (schema). This process is to help the observer acquire a better understanding of the environment or the self. However, the patterns which are used to complete the uncertainties about the self or the environment are sometimes not good estimates of the reality and lead the person/patient to an illusionary perception of the self/environment. In this article, the role of the mirror neuron system in pattern recognition is also explained. Psychological and biological therapeutic implications of this model are discussed and the importance of a link between dynamic and cognitive therapies is rationalized.

Effects of desmopressin (DDAVP) on memory impairment following electroconvulsive therapy (ECT)

Background: Memory impairment is a common adverse effect of electroconvulsive therapy (ECT). Studies on animals and humans suggest that vasopressin improves the cognitive function, and positive effects of desmopressin on memory and learning have been reported. This research was performed for evaluation of the effects of desmopressin in the prevention of memory impairment following ECT. Methods: This randomized, double-blind controlled clinical trial with placebo administration was performed on 50 patients with psychiatric disorders who were candidates for ECT. Subjects in the case group received 60 µm of intranasal desmopressin daily (in three doses of 20 µm). For the control group 0.9% saline solution was administered in the same way. Memory function was evaluated using Wechslers Memory Scale three times a week (the first time before the start of ECT and the second and third times after the third and sixth sessions, respectively). Results were analyzed by t-test and Paired t-test. Results: The mean age of patients was 29 years (range 20–40). During the course of ECT, patients in the control group demonstrated a meaningful decrease in memory scores (from a base score of 80.15–75.45 in the second test and 72.60 in the third test). Despite this, a meaningful increase in memory scores was observed during the treatment with desmopressin in the case group (from a base score of 73.27–75.70 and 79.13 in the second and the third tests, respectively). There was a meaningful difference between the two groups (P < 0.0001). Conclusion: This study confirms the protective effect of desmopressin against memory impairment. The results confirm that memory impairment is a common side-effect of ECT and suggest that desmopressin may prevent ECT-induced memory impairment by its effects on memory and the learning process.

Evaluation of the coincidence of male pattern baldness and pityrosporum group fungal contamination in Iran

Male pattern baldness (MPB) or androgenetic alopecia is one of the most common phenomena among men. Its cause has not been determined, and explanatory theories have included the action of androgens, increased sebaceous secretion, immunological causes, and the action of external organisms. In prior studies the action of the Pityrosporum group fungi was considered. A cross-sectional study of 50 men with MPB was performed to determine if there is a significant statistical coincidence between MPB and Pityrosporum group fungal contamination.