 The researchers propose an investigational therapy of ALS with oral administration of Olanzapine. The rationale for this study is based on the weight-increasing effect of OLN. The clinical trial aims to employ OLN-induced weight gain or weight stabilization as a symptomatic therapy for the loss of appetite. An undesired weight loss of at least 10 of the body weight should be reduced through the weight-increasing effect of OLN. The hypothesis states that the undesired weight loss in ALS patients during treatment with OLN 10mg in combination with Riluzole RIL 100mg is at least 20 percentage points less than for treatment with placebo in combination with 100 mg RIL. 