Design: Systematic review and meta-analysis of randomised trials
Population: 7 trials, 709 adults with depression and insomnia
Primary outcome: Sleep quality and depressive symptoms
Effect: Sleep quality SMD 0.97 (95% CI 0.23 to 1.71), I-squared 91%; depression SMD 0.61 (0.38 to 0.84)

A meta-analysis pooled seven randomised trials, 709 participants with depression and insomnia, all treated with high-frequency repetitive transcranial magnetic stimulation (rTMS) over the left dorsolateral prefrontal cortex.

rTMS improved sleep quality (standardised mean difference 0.97, 95% CI 0.23 to 1.71) and depressive symptoms (0.61, 0.38 to 0.84). Sleep latency did not clearly change, and adverse events did not differ from control (RR 1.09, 0.80 to 1.48).

Heterogeneity for the sleep quality outcome was very high (I-squared 91%), linked to differences in stimulation frequency and background antidepressant use. The authors rate the evidence as very low to low certainty.

For a patient already being considered for rTMS, coexisting insomnia is not a reason to choose otherwise, and sleep may improve alongside mood. It does not make rTMS an insomnia treatment.

Record a sleep measure such as the Pittsburgh Sleep Quality Index before and after an rTMS course.
Insomnia alongside depression does not rule out rTMS.
Continue standard insomnia measures such as CBT for insomnia.
Expect variable response; the trials differed widely.

Why it matters

Sleep is often the symptom patients notice first, and rTMS may not neglect it.

The statistics, in plain English

A standardised mean difference near 1 is a large effect, but its interval is wide and I-squared of 91% means trials disagreed sharply. With low-certainty evidence, the true effect could be much smaller.