Subjects who received exposure along with d-cycloserine showed faster and greater improvement in their PTSD and depressive symptoms, and the benefits persisted after six months of follow-up.

Of course, this was a very small study. A 2017 meta-analysis of 21 studies found that d-cycloserine was superior to a placebo in boosting the short-term effect of exposure-based therapy, though any long-term effects were less consistent. Studies of the drug in rodents have also found that it helps the animals recover from the fear of shocks much faster than a placebo.

How might this work? D-cycloserine is an antibiotic that, like ketamine, increases the activity of glutamate in key brain regions, which promotes connections between neurons. It seems to amp up the molecular machinery of learning. And psychotherapy is all about learning — to overcome fear and to better handle stress, among other lessons.

For decades, psychoanalysts were against medicating anxiety at all, because they believed it would interfere with the therapeutic process. Fortunately, those days are largely over. Many are now comfortable giving patients anti-anxiety benzodiazepines like Klonopin if they are having a hard time grappling with issues that arise in therapy. Treating excessive anxiety can allow patients to better face their pain and fears.

This research suggests we could be doing more to use drugs to turbocharge therapy.

The timing of drug and treatment is probably crucial. In one study, rats were trained to fear a particular context (cage) or a cue (white light) by pairing them with a mild shock. The animals then underwent fear-extinction therapy, either in one long session after receiving a benzodiazepine or in two sessions with the drug given in between. The latter group were more successful at getting over their fear, which suggests that some exposure therapy must precede the medication.

But maybe, with the help of the right drug, just a little therapy could go a long way.

One small study randomized 20 subjects with PTSD to receive just two sessions of therapy in addition to either MDMA (the party drug Ecstasy) or a placebo. Those who got MDMA had fewer PTSD symptoms and were more open and less “neurotic” than those who took a placebo at a two-month follow-up.

It’s not that surprising. MDMA is known to promote openness and lack of defensiveness, both of which might be conducive to attaining insights. Could that wisdom be as enduring as the kind acquired during months of therapy? It’s possible. After all, therapy and prescription drugs like antidepressants change the brain in surprisingly similar ways.