Depressed patients showed inability to inhibit neutral information access to working memory, restrain and delete irrelevant information. This impairment in cognitive inhibition could underlie cognitive slowness and attentional deficits in depression.

Psychiatric disorders, especially depression, are frequent in patients with multiple sclerosis (MS). They are attributed both to the psychosocial impact of a chronic, usually progressive, disabling illness and to cerebral demyelination. Besides, drugs such as corticosteroids and possibly interferon (IFN) may also have depressogenic effects. Major depressive disorders and/or suicidal ideation are a major concern and efforts to identify and minimize these reactions are of much importance. Psychiatric side effects, particularly depression, are widely reported with IFN-alpha and have been suspected with IFN-beta but are not yet fully established. Our review of the literature revealed that most studies discard an association between IFN-beta and depression or suicide. However, few patients, especially those with a history of depression, might be at higher risk for depression when treated with IFN-beta. Overall, considering the uncertainty of a link between IFN-beta and depression and/or suicide, as well as the complete remission of psychiatric complications after IFN discontinuation and/or antidepressant treatment, physicians should closely monitor the psychiatric status of patients, but should not refrain from including them in IFN-beta treatment programs, even when they have past or present depression.

This article presents a prospective study of 71 patients infected with chronic viral hepatitis C and treated with interferon alpha during one year. The objective was to assess the incidence and predictive factors of anxiety and depression symptoms during and after the therapy. Each patient received psychiatric assessment before, during and after treatment, with evaluations using Hamilton-anxiety and MADRS scales. Results confirm the great incidence of depression and anxiety not only during interferon alpha therapy but also after treatment is discontinued. Sleep disorders and MADRS ratings of M4 seem to be predictive of the therapy's side effects. Thus, there seem to be easily discernable parameters allowing depression and suicidal behaviour to be anticipated. This paper emphasises their possible occurrence after the treatment and, therefore, the need for routine assessments after treatment is discontinued. Teams comprising both hepatologists and psychiatrists should complete these assessments. This shows the necessity of interdisciplinary collaboration treatment of this kind.

Adverse effects of interferon (IFN) treatment are common, and efforts to minimize these reactions are of considerable importance. IFN-beta-1a is an established therapy for patients with relapsing-remitting multiple sclerosis (MS). Its psychiatric side effects are debated and not yet fully established. The authors report here the case of a patient on IFN-beta-1a therapy for MS who developed acute delirium, delusion, and depression that ceased with treatment discontinuation. Although he had a history of recurrent major depressive disorder, his prior psychiatric illness had followed a course that was clinically independent of other signs of MS. This observation points out psychiatric vulnerability of patients taking IFN-beta-1a therapy for MS and suggests that IFN-beta-1a may induce or exacerbate preexisting psychotic symptoms.