Loudness dependence of auditory evoked potentials (LDAEP) in clinical monitoring of suicidal patients with major depression in comparison with non-suicidal depressed patients and healthy volunteers: A follow-up-study.

Differences in central serotonergic function due to affective disorders and due to extraordinary situations like suicidality may be visualized using the loudness dependence of auditory evoked potentials (LDAEP). Twenty patients (mean age 43.25 ± 10.85, age range 20-61, 11 male) suffering from a major depressive episode who had either acutely attempted suicide or who had suicidal plans and behavior, which are reflected by item 3 of Hamilton Depression Rating Scale ≥ 3 (suicidality), were included in the study. Furthermore, we intended to compare their LDAEP to those of non-suicidal depressed patients as well as to healthy volunteers, each matched according to age and gender. LDAEP measurement and psychometric tests took place about 2, 5, 9, 16 and 30 days after acute suicidal action or suicide attempts. In contrast to previous results, significant differences in LDAEP could not have been shown in between the suicidal group, or by comparing results of suicidal patients to non-suicidal depressed patients or to healthy volunteers. However, when the LDAEP of non-suicidal depressed patients were compared to healthy volunteers, there was a trend for a higher LDAEP in the healthy volunteers. Further studies are necessary to detect and describe further influences on serotonergic function and confounding factors like medication, smoking, age, gender, comorbidities and methods of suicidal attempts.

Loudness dependence of auditory evoked potentials (LDAEP) in clinical monitoring of suicidal patients with major depression: a pilot study.

Loudness dependence of auditory evoked potentials (LDAEP) is a validated in vivo marker of central serotonergic function. We aimed at measuring serotonergic activity in a follow-up study of suicidal patients. It should be investigated whether suicide attempts or suicidal states cause changes in the LDAEP. Thirteen patients (mean age, 40.9 ± 11.3 years; age range, 20-61, 6 male) with a major depressive episode who had attempted suicide or had suicidal plans (Hamilton Depression Rating Scale item 3 [suicidality] ≥3) were included in the study. LDAEP and psychometric measurements took place about 2, 5, 9 and 16 days after attempted suicide or suicidal action. On day 9, LDAEP was significantly higher compared to day 2 and day 16; there was a similar tendency compared to day 5. Instability of central serotonergic function is suggested resulting in reduced serotonergic activity about 1 week after suicide attempt. Further studies are necessary that include larger samples in order to distinguish between different psychiatric diseases and to consider confounding factors like gender, smoking, medication, impulsivity or lethality of suicidal action.