A cytokine was identified that stimulated the proliferation of T lymphocytes, and a complementary DNA clone encoding this new T cell growth factor was isolated. The cytokine, designated interleukin-15 (IL-15), is produced by a wide variety of cells and tissues and shares many biological properties with IL-2. Monoclonal antibodies to the beta chain of the IL-2 receptor inhibited the biological activity of IL-15, and IL-15 competed for binding with IL-2, indicating that IL-15 uses components of the IL-2 receptor.

An alpha7 nicotinic agonist appears to have positive effects on neurocognition in persons with schizophrenia. Longer trials are needed to determine the clinical utility of this novel treatment strategy.

Objective-Nicotinic acetylcholine receptors are possible therapeutic targets for schizophrenia, as shown by neurobiological and molecular evidence for deficiencies in expression of α 7 -nicotinic receptors. Patients' heavy smoking suggests attempted self-medication through this mechanism. The agent 3-(2,4-dimethoxybenzylidene) anabaseine (DMXB-A) is a partial α 7 -nicotinic agonist and can be taken orally. A phase 1 trial showed evidence for cognitive enhancement in schizophrenia.Method-Thirty-one subjects with schizophrenia received DMXB-A at two different doses and placebo for periods of 4 weeks in a three-arm, two-site, double-blind, crossover phase 2 trial. The MATRICS Consensus Cognitive Battery assessed cognitive effects, and the Scale for the Assessment of Negative Symptoms (SANS) and Brief Psychiatric Rating Scale (BPRS) assessed clinical effects. Subjects continued their current antipsychotic drug during the trial and were nonsmokers.Results-There were no significant differences in the MATRICS cognitive measures between DMXB-A and placebo over the three treatment arms, but the patients experienced significant improvement at the higher DMXB-A dose on the SANS total score and nearly significant improvement on the BPRS total score. Improvement was most notable on the SANS anhedonia and alogia subscales. Examination of the first treatment arm showed effects of DMXB-A on the attention/vigilance and working memory MATRICS domains, compared to baseline. Five subjects developed mild tremor, and nearly half had mild nausea while taking DMXB-A.Address correspondence and reprint requests to Dr. Freedman, Department of Psychiatry C249-32, University of Colorado Health Sciences Center, Denver, CO 80262; Robert.Freedman@UCHSC.edu. Dr. Freedman has a patent through the Department of Veterans Affairs (VA) on the CHRNA7 gene sequence. The VA has also filed a patent disclosure for the use of nicotinic agonists for schizophrenia. Drs. Kem and Soti have patents through the University of Florida on the manufacture and use of DMXB-A (also known as GTS-21) and have a research grant from CoMentis; Dr. Kem is also a consultant for CoMentis. Dr. Buchanan is on the data safety monitoring boards of Pfizer and Wyeth; is a consultant for Memory Pharmaceuticals, Roche, and Organon; is on advisory boards for AstraZeneca, GlaxoSmithKline, Pfizer, and Solvay; and has received drug samples for research from Ortho-McNeil Neurologics and Janssen. Ms. Ball receives grant support and study medication from Eli Lilly. Dr. Gold has been a consultant for Pfizer and receives royalty payments for the Brief Assessment of Cognition in Schizophrenia. Dr. Stevens receives research support from GlaxoSmithKline and Johnson & Johnson and owns equity in Sierra Puente. Drs. Olincy, Martin, and Johnson receive re-search support from Lundbeck. All other authors report no competing interests. One therapeutic target identified by the MATRICS is the α 7 -nicotinic acetylcholine receptor. A possible role for the receptor in schizophrenia was first identi...

Impaired response inhibition is not unique to schizophrenia. However, the nature of their problem is markedly different from that of other psychopathological groups. Possible neural mechanisms underpinning difficulties in triggering inhibitory responses and in the voluntary initiation of actions in schizophrenia are considered.