Several outlets reported this week that a new small NIH-funded study has affirmed an earlier finding that talk therapy could be an unexpectedly effective cure for insomnia – and that curing insomnia could relieve the symptoms of depression. Here’s the New York Times:

Curing insomnia in people with depression could double their chance of a full recovery, scientists are reporting. The findings, based on an insomnia treatment that uses talk therapy rather than drugs, are the first to emerge from a series of closely watched studies of sleep and depression to be released in the coming year.

Although most researchers and clinical psychologists have long considered insomnia a symptom of depression, it turns out that the causality may flow both ways:

Several studies now suggest that developing insomnia doubles a person’s risk of later becoming depressed — the sleep problem preceding the mood disorder, rather than the other way around.

It is an encouraging finding for the field of therapy for depression, and yet more evidence that talk therapy can give rise to deep-seated changes which cannot always be matched by drugs. The study in question focused on a form of cognitive therapy known as CDT-I (“I” for insomnia), but no study has yet been undertaken that compares this type of therapy to another modality such as analytic therapy. Either way, the tidal wave of new evidence underscoring the timeless power of dialogue continues to color national conversations on mental health.