EXCESS CARDIOVASCULAR AND SUICIDE MORTALITY OF AFFECTIVE-DISORDERS MAY BE REDUCED BY LITHIUM PROPHYLAXIS

The mortality of patients suffering from affective disorders is much h igher than that of the general population; this excess is due to both suicides and cardiovascular disease. During long-term lithium treatmen t, the overall mortality has not been found to differ significantly fr om that of the general population but the question remains whether thi s lowering, if it is in fact caused by lithium, is due to a reduction in suicide frequency or cardiovascular mortality, or both. We analysed data from 827 previously studied patients and used a procedure that e stimated both overall mortality and cause-specific mortalities by sing le-case analysis. For overall mortality, the ratio of observed deaths (among the patients) to expected deaths (in the general population) wa s 1.14, which is not significantly different from 1.0; this was also f ound in our previous analysis. In the whole patient group, comprising 5600 patient years under lithium treatment, seven suicides were observ ed and 1.3 expected, resulting in a standard mortality ratio of 5.22; this is significantly > 1.0, but markedly lower than that found in pat ients with affective disorders not given lithium. Cardiovascular morta lity was not found to be higher in our patients than in the general po pulation. In view of the fact that a placebo-controlled mortality stud y under long-term conditions is neither ethically nor practically feas able, our findings cannot prove definitively that long-term lithium tr eatment counteracts factors responsible for the excess suicide and car diovascular mortality of affective disorders. However, our observation s are compatible with such a notion.