Psycho-behavioural inhibition is characteristic of major depressive disorder and frequently recedes after the other depressive symptoms. This may induce an important psychosocial impairment which could be a risk factor for relapse.
Methods: The aim of this eight weeks, multicentric, randomized, double blind, placebo controlled trial was to assess the efficacy and safety of sulbutiamine (Arcalion) [600 mg p.d.] on the symptoms of psycho-behavioural inhibition of inpatients with DSM III-R defined Major Depressive Episode (MDE) treated by adjusted doses of clomipramine [75 to 150 mg pd]. Moderate doses of hypnotics and anxiolytics without potential activity on the mood were authorized during the trial. The MDE was assessed with the MADRS, HAM-A and CGI scales. Patients who did not respond adequately to the antidepressant treatment were prematurely withdrawn from the trial. The three Sheehan Disability Scales (SDS), the Norris Visual Analogue Scale (VAS) and the Depressive Psychomotor Retardation Scale (ERD) were used to monitor psycho-behavioural inhibition.
Results: The mean intake scores were, as expected, fairly high: MADRS (32), HAMA-A (23), CGI (5) and ERD (27). The SDS and EVA scores showed that the patients felt severely handicapped in their social, professional and family life functioning as well as in their emotional, affective, cognitive and behavioural performances. At four weeks the MADRS, HAM-A and CGI scores indicated that the global improvement of the MDE was comparable in both treatment groups. However, the scores at the EVA and SDS scales showed that the patients treated with sulbutiamine were significantly less incapacitated than the placebo group in all of the various facets (affective, cognitive, emotional, behavioural) of psycho-behavioural inhibition. Furthermore, the safety data shows that both treatment groups were comparable and in particular that sulbutiamine had not induced any inappropriate behaviour, including suicide attempts, or mania.
Conclusions: Sulbutiamine has no antidepressive effect but it can hasten the resorption of psycho-behavioural inhibition occurring during major depressive disorder and thereby facilitate the rehabilitation of patients in their social, professional and family life functioning.