Trail making and cognitive set-shifting.

We tested the hypothesis that Part B of the Trail Making Test (TMT) is a measure of cognitive set-shifting ability in 55 normal subjects with the conventional (written) TMT and a verbal adaptation, the "verbal TMT" (vTMT). The finding of a significant association between Parts B of TMT and vTMT (r = 0,59, p < 0,001), after correcting for age and education, supports the view that Part B of TMT is a valid measure of the ability to alternate between cognitive categories.

Sustained long-term improvement with clozapine in schizophrenia.

The present paper reports the long-term use of clozapine in a prospective sample of 46 chronic schizophrenics. In six months, 21 subjects had been excluded for a number of reasons. In four of them the reasons for exclusion were related to lack of response or adverse effects. The median daily clozapine dose was 400 mg in the remaining 25 patients. As a whole, there were remarkable improvements in core dimensions of psychopathology, global cognitive status, and level of functioning. We confirmed that clozapine is effective in a subgroup of schizophrenics with the severest forms of the disease. If tolerated after the first few months it leads to progressive gains in several domains of behavior. Clozapine should be tried in every patient with schizophrenia in whom positive symptoms, disorganization, or bizarre behavior are a matter of incapacitation despite efforts to keep them under control with other drugs.