The remission was sustained as it was possible to discontinue the naltrexone after 2 months without precipitating a relapse [Lerner et al. 1997]. However, the ‘success’ of pharmacotherapy for HPPD should be treated with caution as this disorder appears to have a high propensity for spontaneous remissions – up to 50% of cases within a few months [Abraham, 2001]. In this context, the rarely

ever documented occurrence of flashbacks in controlled studies of hallucinogen Inhibitors,research,lifescience,medical action should be mentioned. Apparently a favourable protective ‘setting’ may prevent the development of anxiety and psychotic decompensation as well as the loss of self control. In our case, a spontaneous remission coinciding with lamotrigine treatment appeared unlikely after a 13-year duration of unrelenting symptoms. With a multitude of potential etiologies, it may not be possible to put forward a unified pathophysiological model of HPPD. Rather, a multifactorial origin of HPPD-related phenomena is to be assumed that may differ from case to case. The range Inhibitors,research,lifescience,medical of case-specific variables may extend from learning and kindling effects, individual reaction patterns to mental trauma and weak self esteem to other psychophysic vulnerabilities [Hermle et al. 2008]. Additionally, Inhibitors,research,lifescience,medical only

a small spectrum of hallucinogens seem capable of eliciting flashbacks, with LSD being the leading causative agent. In addition to the illicit nature of its use in an ‘uncontrolled’ environment, the long half life of LSD and

the above-mentioned destabilizing Inhibitors,research,lifescience,medical effect on self realization may contribute to the relatively frequent development of flashbacks observed with this particular drug. Closely related to LSD in its psychotropic actions is psilocybin, which produces similar but shorter-lasting intoxications. Interestingly, there is only one documented case of HPPD following ingestion of Psilocybe semilanceata mushrooms Inhibitors,research,lifescience,medical in the psychiatric literature, despite its common use in the hippie subculture of the 1960s and 1970s [Espiard et al. 2005]. The incidence of mental disorders in 200 Native Americans of the Navajo tribe after ritual use of mescaline was the subject of a recent study by Tofacitinib baldness Halpern [Halpern, 2003]. Over a 3-year period of observation, not a www.selleckchem.com/products/Y-27632.html single case of HPPD was detected. The clinical relevance of flashbacks as sequelae of LSD and other biogenic Dacomitinib and synthetic hallucinogens needs to be reassessed. In the light of more recent studies, earlier estimates of 5–54% incidence seem exaggerated – a rate of 5% or lower appears more realistic. With the Cochrane Society’s strict criteria for evidence-based medicine as a yardstick, our current knowledge does not allow for any empirical recommendations as to the rational pharmacotherapy of HPPD. Future clinical research needs to be directed towards randomized controlled trials to establish sound treatment guidelines, in particular for chronic forms of HPPD [Halpern and Pope, 2003].