Social cognition: an early impairment in dementia of the Alzheimer type.

OBJECTIVE: A core component of social functioning is the capacity to attribute mental states to others and to understand intention as psychologic cause. The hypothesis of this study was that dementia of the Alzheimer type (DAT) patients show an impaired understanding of psychologic cause although they remain able to understand physical causality. METHODS: To test this hypothesis, 20 elderly adults with DAT, 20 healthy age-matched controls, and 20 healthy young adults were presented a cartoon task requiring them to process physical or psychologic cause of events. RESULTS: Patients with DAT at onset scored significantly lower than controls when they had to reason about psychologic causation, while they did not differ for reasoning about physical causation. Consistent with these results, patients with DAT showed significantly lower scores in psychologic reasoning as compared with their scores for physical causality. Instead young and elderly healthy adults scored similarly for the 2 types of causality and the 2 groups did not differ in their scores. These results suggest that impaired understanding of intention in others may be considered as an early socio-cognitive index of onset of DAT. A post hoc division of the group of patients with DAT into 2 subgroups according to Mini Mental State (MMS) scores showed that the group with the more severe MMS scores not only had lower scores for psychologic causality but also showed impairment in reasoning about physical causality involving persons. Physical causality involving objects remained relatively preserved. CONCLUSIONS: The remarkable deficit in attribution of intention in our patients with DAT at onset and the following deterioration of their performance in reasoning about physical causality with persons may reflect progressive dysfunction of the superior temporal sulcus in Alzheimer disease.

A double-blind sham controlled study of right prefrontal repetitive transcranial magnetic stimulation (rTMS): therapeutic and cognitive effect in medication free unipolar depression during 4 weeks.

BACKGROUND: Transcranial magnetic stimulation (TMS) has become a therapeutic tool in psychiatric diseases. METHODOLOGY: The objective was to evaluate the efficacy of TMS in unipolar depression: the percentage of responders (>50% HDRS reduction) and remission (HDRS score < or =8, after four weeks of active TMS treatment in depressed patients free of any antidepressive agent versus placebo-TMS. RESULTS: 27 patients were randomized in two groups: rTMS (N=11) versus sham TMS (N=16). Statistical differences were detected between sham and TMS treated groups on remission (0/16 versus 4/11 p=0.032, 1/16 versus 6/11 0.028 and 1/16 versus 7/11 p=0.011 at day 14, day 21 and day 28, respectively) and on response (2/16 versus 5/11 at day 14 (NS), 2/16 versus 7/11 p=0.0115 at day 21 and 1/16 versus 7/11 (p=0.025) day 28, respectively, using the exact Fisher test). Significant differences were observed between day 1 versus day 8 (p<0.01), day 15, day 21 and day 28 (p<0.001) in TMS group and only versus day 21 (p<0.01) and day 28 (p<0.05) for the sham group. ANOVA comparison between TMS and sham groups was significant at day 14 and day 28 (p<0.05). LIMITATIONS: The few number of patients. CONCLUSION: Our study has shown an efficacy of right rTMS in free medication unipolar depression over a month. Nevertheless, number of patients included is limited and multicentric studies will be necessary to specify the antidepressive action of TMS.