Middle latency evoked potentials in melancholic depression

Electroencephalographic Parameters Differentiating Melancholic Depression, Non-melancholic Depression, and Healthy Controls. A Systematic Review

“…Regarding the quality of individual studies, 10 studies were classified as of low quality ( 22 , 25 , 28 , 30 , 31 , 34 , 36 – 38 , 42 ), eight studies as of high quality ( 23 , 24 , 27 , 29 , 32 , 33 , 35 , 40 ), and six studies of moderate quality ( 26 , 39 , 41 , 43 – 45 ).…”

“…Two out of three studies ( 27 , 29 , 32 – 35 ) had control groups of both HC and non-melancholics, although the study by Kerr et al ( 29 ) did not compare the two MDD groups. The remaining three studies had a single control group of HC ( 28 , 30 , 31 ).…”

“…Of these, only two studies reported age limits as part of the inclusion criteria ( 28 , 32 ). Three studies were less specific, reporting an ICD/DSM-diagnosis for the eligible patients, but otherwise giving loose or very brief criteria, not reporting inclusion/exclusion criteria for the control group(s) ( 30 , 31 , 34 ). One study referred to another publication for eligibility criteria ( 33 ).…”

“…Concerning clinical and demographic characteristics of participants, all studies lacked data on one or several variables, namely medication status ( 34 ), male/female sex ( 34 ), handedness ( 27 , 29 – 31 , 34 , 35 ), socioeconomic status (e.g., years of education, employment status) ( 27 – 32 , 34 , 35 ), inpatient/outpatient status ( 27 – 33 , 35 ), comorbidity ( 34 ) and depression severity ( 28 , 30 , 31 , 34 ). All studies, except one for one ( 34 ), included information on participants' medication status.…”

“…The complex design of Kerr et al ( 29 ) involved deconvolution analysis and fitting data to a neuronal transmission activity model, leading to the result that melancholics were found to have increased thalamocortical transmission delays compared to HC, with the size of the increase strongly correlated with depression severity. Using the intensity dependence of the auditory evoked potential (IDAEP), an ERP measure regarded as a reliable indicator of central serotonin function in depression, Fitzgerald et al ( 27 ) could distinguish patients with melancholic depression from patients with non-melancholic depression and HC, while Khanna et al ( 30 ) found no significant differences between groups in a study investigating both auditory and visually evoked potentials. Concentrating on visual stimuli in a cognitive go/no-go task, Quinn et al ( 35 ) also failed to separate patients with melancholic depression from control groups when comparing amplitude and latency of the P200, N200, and P300 components.…”