Table 3.

Effects of CBT and PC on the change in spectral power-derived indices

	Peak 1 delta % powera	Delta slopeb	Delta power	Theta power	Alpha power	Sigma power	Beta power
CBT (n = 16)	0.066 (.26)	−0.00018 (.001)	1.4 (2.9)	−0.029 (0.06)	−0.41 (.9)	−0.52 (1.1)	−0.13 (.5)
PC (n = 14)	−0.22 (.37)	0.0012 (.001)	2.2 (2.3)	−0.037 (0.09)	−0.46 (.8)	−0.50 (.7)	−0.23 (.3)

Data are shown as mean posttreatment minus pretreatment differences (SD). Differences in power indices were computed with logarithmically transformed data. Delta, alpha, sigma, and beta power is relative power (power in the indicated frequency band divided by the sum of power in all bands and therefore dimensionless) averaged over the entire night. Peak 1 delta % power is the peak delta power in the first non-rapid eye movement period expressed as a percentage of total power over the night. Delta slope is the slope of the best-fit line of peak delta power over the night. Because it is fit to logarithmically transformed power, it is the exponent of the best-fit exponential function.

^aP < 0.10 for cognitive behavioral therapy (CBT) vs placebo-controlled condition (PC) difference.

^bP < 0.05 for CBT vs PC difference.