David P. Geaney

Effect of central cholinergic stimulation on regional cerebral blood flow in Alzheimer disease

Patients with Alzheimer disease (AD) had reduced regional cerebral blood flow (rCBF) in the posterior parietotemporal region compared with controls, as determined with technetium-99m hexamethyl propyleneamine oxime and single photon emission tomography. Central cholinergic stimulation with physostigmine produced a focal increase in rCBF in the posterior parietotemporal region in the patients with AD but not in controls.

Haloperidol enhances latent inhibition in visual tasks in healthy people

Abstract We have previously shown that 0.5mg haloperidol (IV) increased latent inhibition in one of two visual tasks. The present study analysed the effects of a higher dose of haloperidol (1.0 mg, IV) on latent inhibition in these two visual tasks in healthy volunteers in a randomised controlled trial. In the task where 0.5 mg haloperidol had enhanced latent inhibition, 1.0 mg had the same effect, thus replicating the previous result. In the task where 0.5 mg haloperidol had been ineffective, 1.0 mg haloperidol enhanced latent inhibition in high schizotypal subjects only. This indicates that subjects with higher schizotypy scores are more sensitive to dopamine blockade. A comparison of the results from the studies at the two different doses suggests a dose dependence of haloperidol’s effects on latent inhibition that parallels results from animal work.

Antipsychotic drug effects in a model of schizophrenic attentional disorder: A randomized controlled trial of the effects of haloperidol on latent inhibition in healthy people

We studied the effects of haloperidol (0.5 mg, intravenously) on latent inhibition in an auditory paradigm and two visual paradigms in healthy subjects. Haloperidol increased latent inhibition in one visual paradigm and tended to increase latent inhibition in an auditory task, compared to saline-injected controls. These results indicate that haloperidol can enhance the selectivity of attention. In contrast, previous studies have reported that acute schizophrenics show reduced latent inhibition.

Intravenous administration of haloperidol to healthy volunteers: lack of subjective effects but clear objective effects

Healthy volunteers who received i.v. injections of either saline or haloperidol (0.5 or 1.0 mg) made visual analogue scale ratings of subjective mood, tension, shakiness and the global feeling of having received an active drug. The subjective ratings of volunteers who received haloperidol did not differ, overall, from those who received saline. In contrast, the drug caused clear objective changes in several psychological tests. I.v. administration of low doses of haloperidol may permit double-blind testing of the psychological actions of haloperidol in healthy volunteers.

Schizotypy and height: Reduced height in high-schizotypal healthy men

Abstract We analysed the relationship between schizotypy and height in healthy subjects. One hundred and ninety-seven subjects gave information about their height and completed a computerised schizotypy questionnaire. Men with high schizotypy scores were shorter than their low schizotypal peers. This finding parallels reports of reduced stature in schizophrenic patients and so supports the validity of schizotypy as an index of psychosis-proneness.

Depression: a cultural panic attack

Mario Maj overlooks the wider importance of an evolutionary perspective in discussing when depression becomes a mental disorder.[1][1] He rejects the contextual approach, which considers whether depression is a normal response to circumstances, because of the difficulty of being certain that it is a