[Electroencephalographic markers of alexithymia in patients with moderate depression]

To search for electroencephalographic markers of alexithymia in patients with moderate depression.

Sixty-four right-handed inpatients (20 men and 44 women, mean age 29.3+10.7 years), were studied. The level of alexithymia was assessed by the Russian version of the Toronto Alexithymia Scale (TAS-20-R). Patients were stratified into 4 groups by TAS-20-R scores. Two main groups of 22 patients each included people with high (>60 scores) and low (20-51 scores) levels of alexithymia. Control groups included 10 patients with 60-85 scores and 10 patients with 52-54 scores. Current methods of electroencephalographic analysis were used.

Alexithymia in patients with moderate depression is characterized by a restructuring of the integrative activity of the brain detected by electroencephalography at rest. Patients with high alexithymia differ from those with low alexithymia by (1) lower values of the real part of the coherence between the frontal and anterior temporal leads of the left hemisphere in the band 28-30 Hz; (2) lower values of the imaginary part of coherence in the band 11-12 Hz between the posterior temporal and parietal as well as the posterior temporal and occipital cortical zones of the right hemisphere; (3) higher rates of the real part of the coherence between the right frontal and central leads in the frequency ranges 12-14 and 6-7 Hz; (4) large values of the imaginary part of the coherence between the left parietal and right posterior temporal cortex in the band 24-26 Hz; (5) higher values of the square of the coherence modulus between the left frontal and anterior temporal cortical zones in the band 17-18 Hz.

Large cortical representations with involvement of theta, alpha, beta-1 and beta-2 rhythms can contribute to the pathogenesis of alexithymia.