Intellectual efficiency in manic-depressive patients treated with lithium. A control study

A longitudinal study of 21 non-hospitalized manic-depressive subjects treated with lithium was carried out over a 3-year period: year 1 (Y1), year 2 (Y2), year 3 (Y3). A control group C of 21 subjects matched for age, sex and educational level was compared to Y1, Y2 and Y3 using the Cattell Intelligence Scale, the immediate memory recall test of numbers, the Code Test (WAIS), the 15-Word Test and the Benton Visual Retention Test. The vocabulary test of Binois and Pichot was first applied to C and Y1 to test the homogeneity of intellectual level between these two groups. A strategy of variance analysis followed by non-parametric Mann-Whitney and Wilcoxon tests was applied for statistical analysis of the results. Generally, except for the Cattell test, the patients presented lower scores than the control group. This decrease was not accentuated as time elapsed; the non-verbal were not affected more than the verbal tests. A clinical analysis was carried out relating the importance of the criteria "deterioration" to four other criteria: "age", "gravity and duration of illness ", "history of E.C.T." and "insufficient mood stabilization". The factor "gravity of the illness" was slightly more frequently associated with factor deterioration.