Brain Changes Associated With Long-Term Ketamine Abuse, A Systematic Review.

Recently, the abuse of ketamine has soared. Therefore, it is of great importance to study its potential risks. The effects of prolonged ketamine on the brain can be observationally studied in chronic recreational users. We performed a systematic review of studies reporting functional and structural brain changes after repeated ketamine abuse. We searched the following electronic databases: Medline, Embase and PsycINFO We screened 11,438 records and 16 met inclusion criteria, totaling 440 chronic recreational ketamine users (2-9.7 years; mean use 2.4 g/day), 259 drug-free controls and 44 poly-drug controls. Long-term recreational ketamine use was associated with lower gray matter volume and less white matter integrity, lower functional thalamocortical and corticocortical connectivity. The observed differences in both structural and functional neuroanatomy between ketamine users and controls may explain some of its long-term cognitive and psychiatric side effects, such as memory impairment and executive functioning. Given the effect that long-term ketamine exposure may yield, an effort should be made to curb its abuse.

[Psilocybin compared with escitalopram for depression]. / Psilocybine vergeleken met escitalopram bij depressie.

Carhart-Harris et al. performed a study in which they compared psilocybin in combination with psychotherapy to escitalopram in combination with psychotherapy for depression. In this commentary, the author first summarizes the study results: in this double blind randomized controlled trial, psilocybin yielded an antidepressant effect comparable to escitalopram. Then, the author reflects on both the implications this study might have for future clinical practice and on the still existing shortcomings pertaining to psychedelic research in psychiatry. Psychedelic treatments might become guideline-based treatment after phase III trials have been performed. However, to date, only phase II trials have been performed and little is known about psilocybin's ability to maintain its antidepressant effect. In addition, blinding issues with psychedelic treatments remain, and media might have presented a premature and overly positive image of psychedelics as a possible treatment for psychiatric illness.

[New indications for existing drugs; repurposing in psychiatry and addiction medicine]. / Nieuwe indicaties voor bestaande geneesmiddelen.

Repurposing is the discovery - whether or not by accident - of a new use for an existing product, for example, a new indication for a drug. In the past, several psychotropic drugs have received their place in the treatment arsenal via this route. Both in psychiatry and addiction medicine, there is an important need for new treatments with new working mechanisms. Potential new uses in both psychiatry and addiction medicine of several drugs that have already been registered for other indications are currently under study. For example, the anaesthetic ketamine is found to have a strong antidepressant effect. In addition, both the anti-epileptic topiramate and the muscle-relaxant baclofen could possibly prevent relapse in addictive behaviours.