NEW DATA ON EXTENDING THE EFFFECTS OF IV KETAMINE: Implications for countering the effects of stigma.
John Krystal of Yale U. in an article in Proceedings of the National Academy of Sci. (2023) gave new information about the anatomical and physiological effects of ketamine and about how to extend its effects. Ketamine in animals acutely (in a matter of hours) increases spines, synapses, and dendrites and physiological connectivity in neurons in the prefrontal cortex. Data now support these findings in humans with depression, but AD effects of ketamine tend to dissipate over a period of 3 to 5 days and require repeated infusions to maintain the improvement. Synaptic density can be measured with SV2A and this can be enhanced with a Navitor Pharmaceuticals drug acting on mTORC1. Surprisingly low doses of rapamycin, an inhibitor of mTOR1, extends the duration of AD effects of ketamine, increasing the response rate at 2 weeks of 13% to 41%. Ketamine restores only the spines that have been reduced in depression and rapamycin is thought to extend the duration of the restored spines. It may do this by increasing the neurotropic effects of microglia. The tripartite synapse of pre and post synaptic neurons and astrocytes, may now be better described as the tetrapartite synapse with the inclusion of microglial.
Adding psychotherapy to the effects of ketamine in PTSD increases and extends efficacy.
AD effects of ketamine can be extended with cognitive behavioral therapy. Thus, ketamine increases synaptic efficacy, synaptic density, glutamate homeostasis, and experience-dependent neuroplasticity. Extending the persistence of these effects by various chemical and psychotherapeutic mechanisms may give new ways of enhancing and prolonging the therapeutic effects of this rapidly acting agent.
Interestingly, Kaye at Yale U. reports that in contrast to transient effects of ketamine, the AD effects of therapy-assisted psilocybin appear to be very long lasting and the associated increases in spines persist for longer than 37 days. Another psychedelic MDMA that is effective in PTSD causes large increases in spines, although they are less persistent and are gone by 34 days.
Editors Note: As we have previously highlighted in the BNN, these data on ketamine and other psychedelics reversing the anatomical and physiological deficits in prefrontal neurons of depressed animals and humans (spines, dendrites, synapses and intercellular communication), give a new view of the real, reliable, and replicable neurological defects accompanying depression. The rapid correction of these neural abnormalities in conjunction with the rapid induction of antidepressant effects are not only paradigm shifting from a treatment perspective, but have major implications for the assertion that there is a neurobiological basis of depression and its treatment.
As such, these data should do much to counter the continuing stigma too often accompanying the term “mental” illness that it is somehow not as real as other medical and neurological conditions, and as it is often asserted that “it is just all in one’s head.” This picks up on the unfortunate associations and definitions of “mental” as imaginary, all in the mind, and evanescent and that mental illness can readily be countered with effort and will power such as “pulling oneself up by the bootstraps,” (the latter of which is in itself a logical impossibility.)More Data that Long Term Lithium Treatment Does NOT CAUSE RENAL TOXICITY (more than those on valproate).
In a recent meeting, Mark Weiser of Sheba Medical Center analysed data from “from the Clalit Health Services (CHS) database, the largest provider of health insurance in Israel, n=4.8 million, representing over 50% of the Israeli population. This study examined lithium use between the years 2000 and 2022, focusing on its impact on kidney and thyroid function…(and) compared all patients receiving lithium (n=19,433) to all patients receiving valproic acid (n=44,524). There was no different in the life-time rates of dialysis between patients treated with lithium and patients treated with valproic acid (1.03% vs 0.99%, p = 0.683). A lifetime diagnosis of hypothyroidism was more common in patients receiving lithium (21.84%) in comparison to patients treated with valproic acid (8.83%, p = <0.0001). Conclusions: In this large population study, treatment with lithium was not associated with decreased kidney function but was associated with a clinical diagnosis of hypothyroidism. These factors should be taken into account when considering treatment with lithium.”
Editors Note: In patients on lithium, overtime there are small decreases in estimated glomerular filtration rate (eGFR), but these do not differ from those seen in physiological age adjusted eGFR in the general population. These data are convergent with the large national studies of Kessing et al in Denmark and indicate that the long-held view of lithium causing undo renal toxicity are not accurate and are based on inappropriate suppositions without an adequate control group. They found more end-stage renal dysfunction in bipolar patients treated with anticonvulsants than with lithium.
THERE IS A GRAVE UNDERUTILIZATION OF LITHIUM DUE IN LARGE PART TO THE FALSE ASSUMPTION THAT IT CAUSES EXCESS RENAL TOXICITY. PATIENTS AND CLINICIANS SHOULD BE MADE AWARE OF THE NEW DATA THAT THIS IS LIKELY RELATED TO POOR METHODOLOGY AND BEGIN TO MORE FREQUENTLY THINK ABOUT USING LITHIUM — UNEQUIVOCALLY THE BEST DRUG FOR THE TREATMENT OF BIPOLAR DISORDER. LITHIUM ALSO HAS THE BEST DATA FOR REDUCING EPISODES OF BOTH DEPRESSION AND MANIA AND FOR HAVING POSITIVE EFFECTS IN PREVENTING SUICIDE. USING LITHIUM MORE OFTEN WILL UNDOUBTEDLY MARKEDLY IMPROVE PATIENTS WELL BEING AND SURVIVAL. THIS EDITOR BELIEVES THAT GIVEN LITHIUM’S MULTIFACETED ROLE IN AMELIORATING ALMOST ALL ASPECTS OF THE COURSE OF BIPOLAR DISORDER, IT SHOULD BE CONSIDERED A “DISEASE MODIFYING DRUG.” THERE ARE MULTIPLE DISEASE MODIFYING DRUGS FOR TREATMENT OF MULTIPLE SCLEROSIS, AND EXPERTS IN THAT FIELD BELIEVE THAT DISEASE MODIFYING SHOULD BE STARTED AS EARLY AS POSSIBLE AFTER FIRST DIAGNOSIS. A SIMILAR CONCLUSION WOULD NOW APPEAR APPROPRIATE FOR LITHIUM.
Of note is the other widely held reason for not using lithium more often is that it causes hypothyroidism. While this is clearly correct based on the Weiser study and many other data, patients should be aware that this well-known condition is readily correctable with thyroid hormone replacement and does not produce an undo burden on patients.
Since lithium has many other assets including: increasing hippocampal volume; protecting memory; and increasing the length of telomeres (critical to sustaining good medical and psychiatric health), its wider use in bipolar disorder should be a no brainer. However, it is likely (like most revisions in medical lore) to take 10 years or more before this re-evaluation of lithium has an impact on conventional treatment decisions, so physicians should make very active and conscious decisions about changing their routine choices of treatment for each patient with bipolar disorder.
