[Therapy of cognitive deficits in schizophrenia with acetylcholinesterase inhibitors. A systematic overview]. / Therapie kognitiver Defizite durch AChE-Hemmer bei Patienten mit Schizophrenie. Eine systematische Ubersicht.

Patients with schizophrenia suffer from cognitive deficits which are important predictors of functional outcome. Alterations such as reduced muscarinic and nicotinic receptors in the central cholinergic system in patients with schizophrenia may contribute to these cognitive impairments. Because such deficits do not respond to neuroleptic treatment, different approaches have been developed regarding pharmacological treatments that enhance central cholinergic transmission, e.g. with acetylcholinesterase inhibitors. In this review the pathophysiology of cognitive impairment in schizophrenia, results of studies using acetylcholinesterase inhibitors (donepezil, rivastigmine, physostigmine, and galantamine), and future research strategies are presented. Till now randomized, placebo-controlled studies exist only for donepezil and rivastigmine, and none could replicate the positive results of previous trials with open designs. More trials with higher numbers of patients are needed, particularly for substances with more complex mechanisms of action (e.g. galantamine).

[Subjective experience of a computer-assisted cognitive training by patients with schizophrenia]. / Subjektives Erleben eines computergestützten kognitiven Trainings durch Patienten mit Schizophrenien.

Cognitive training is an important aim of treatment for patients with schizophrenia. However, computer-based cognitive training is still not widely used, and there are reservations concerning the use of computers in psychiatric treatment. In a multicentre study, 64 patients with schizophrenia were investigated before and after completing a 5-week course of computer-based cognitive training using the program Cogpack. In addition to self-rating of computer anxiety (CARS) and subjective well-being (SWN), patients underwent semistructured interviews evaluating attitudes towards the training. The training was rated as highly acceptable by patients and experienced as very effective. Patients' expectations of possible training effects were largely met. The training ranked high in patients' judgement compared with other treatments received. Besides improvement in cognitive function (primary effect), patients enjoyed the training and reported increased self-esteem and progress in using computers (secondary effects). Computer anxiety scores at onset of treatment did not exceed normal values. After completion of the training, these scores were significantly reduced and subjective well-being significantly increased.

Attention-dependent allocation of auditory processing resources as measured by mismatch negativity.

Mismatch negativity (MMN) is a pre-attentive event-related potential measure of echoic memory. However, recent studies suggest attention-related modulation of MMN. This study investigates duration-elicited MMN in healthy subjects (n = 12) who were performing a visual discrimination task and, subsequently, an auditory discrimination task in a series of increasing task difficulty. MMN amplitude was found to be maximal at centro-frontal electrode sites without hemispheric differences. Comparison of both attend conditions (visual vs. auditory), revealed larger MMN amplitudes at Fz in the visual task without differences across task difficulty. However, significantly smaller MMN in the most demanding auditory condition supports the notion of limited processing capacity whose resources are modulated by attention in response to task requirements.