Perception of speech in mood disorders

Cognitive impairment in affective disorders causes a deterioration of information processing in the nervous system, which impairs receiving information from the environment. In affective disorders, the changes affect almost all cognitive areas; however, understanding speech as a complex cognitive function that integrates thinking, reasoning, understanding, and engaging processes of memory and attention, has little been investigated.

There has been an increase in the number of reports on the functioning of central auditory processing (CAP), which affects the processes of speech understanding in the brain despite any loss of hearing. The occurrence of CAP abnormalities in mental and neurological disorders, such as schizophrenia, autism, depression, alcohol addiction, attention deficit syndrome, anorexia, dyslexia, and Alzheimer’s disease has been demonstrated.

It has been found that cortical auditory perception is impaired in affective disorders, and its mechanisms could be regulated by the serotonergic system. Cortical hearing disorders are likely to reflect some of the brain dysfunction found in mood disorders and involve additional areas of the brain to achieve adequate auditory performance in patients with depression.

In Poland, tests have recently been developed for the assessment of speech understanding. Their reliability allows testing in various conditions, also taking into account the differences in speech perception before and after pharmacological therapy.

The aim of the article is to systematise the existing knowledge on speech understanding processes in the context of affective disorders, including CAP functioning, as well as to demonstrate the possibilities for further research.