Placebo-controlled double-blind trial of mianserin hydrochloride

Abstract

1 Mianserin hydrochloride has been reported to be an antidepressant. To establish that a new drug is an antidepressant, it must be clearly superior to standard antidepressants or it must be compared with a placebo. The ethical problems raised by using a placebo in severely depressed patients led to the restriction of the present trial period to 14 days.

2 Patients were transferred to a four-bedded ward 3 d before beginning the trial proper and were prescribed nitrazepam 5 mg four times daily. Patients diagnosed as suffering from manic-depressive psychosis—depressed (ICD 296.2), were retained and randomly assigned to two groups, one receiving mianserin, the other placebo. For the pre-trial period and throughout the trial, patients' sleep was estimated by themselves and by nurses. Patients rated themselves on the Beck Self-Rating Inventory (BSRI) before the trial and at weekly intervals thereafter. Nurses rated the patients twice daily on a seven-point global rating scale of depression. A blood sample for estimation of mianserin levels was taken on day 14.

3 Eighteen patients received placebo and 21 mianserin. On the BSRI, the mianserin group improved significantly, whereas the placebo group showed no change. The mean daily nurse ratings showed some improvement in the placebo group but a greater improvement in the mianserin group, particularly towards the end of the 14 days. Sleep (nurses' observations) improved significantly in the mianserin group from the first night of the trial and over the following 2 weeks. Sleep as assessed by the patients also improved significantly on mianserin. Blood levels of mianserin did not correlate significantly with changes in mood or sleep.

4 This study confirms that mianserin is an antidepressant. The mianserin group showed an improvement in sleep which, since it started from the first night of the trial, was probably due to the hypnotic sedative properties of the drug.