ANTIDEPRESSANT PATENTS - 1995-1997

Whilst considerable advances have been made in the treatment of depres sion, particularly with the advent of the selective serotonin re-uptak e inhibitors (SSRIs), current drug treatments are unsatisfactory for s everal reasons. In particular, they fail to treat approximately 30% of patients, and they are slow in onset, requiring 3 - 8 weeks for effic acy. Consequently, the search for new antidepressants is now focussed on providing solutions to these problems. This review surveys the anti depressant patent literature for the years 1995 - 1997 in the context of these issues. Progress has been made, particularly with combination s of SSRIs and 5-HT autoreceptor ligands. Initially this has been achi eved by combining individual drugs with single modes of action, but si ngle compounds with multiple activities have also been patented. There has also been extensive patent activity suggesting that agonists at p ostsynaptic 5-HT1A and 5-HT2C receptors and antagonists at presynaptic 5-HT1B autoreceptors possess antidepressant potential. While the majo r focus of research has been the enhancement of serotonergic neurotran smission, attention is now turning to other mechanisms of action. In p articular, growing interest in the role of corticotrophin-releasing fa ctor (CRF) in stress-related disorders, and recent clinical trials wit h the substance P antagonist, MK-869, has seen a rapid expansion in pa tent activity around CRF and tachykinin receptor antagonists for the t reatment of depression.