Effectiveness of an internet intervention (Deprexis) for depression in a united states adult sample: A parallel-group pragmatic randomized controlled trial.

OBJECTIVE: To examine the effectiveness of an Internet intervention for depression with a randomized, controlled trial in a large sample of adults recruited from the United States. METHOD: The current study examines the effectiveness of Deprexis, an Internet treatment for depression that was provided with relatively minimal support. There were 376 treatment-seeking adults (mean age = 32 years; 74% female; 77% Caucasian, 7% Asian, 7% multiple races, 4% African American, and 11% Hispanic/Latino) with elevated depression (Quick Inventory of Depressive Symptoms-Self-Report [QIDS-SR] > = 10) who were randomized to receive an 8-week course of treatment immediately (n = 285) or after an 8-week delay (n = 91; i.e., waitlist control). RESULTS: Intention-to-treat analyses indicated that treatment was associated with greater reduction in self-reported symptoms of depression (effect size d = .80) and 12 times greater likelihood of experiencing at least 50% symptom improvement compared with waitlist control. Similar effects were observed for several secondary outcomes, such as interviewer-rated depression symptoms, well-being, and depression-related disability. Treatment effects for symptoms of social anxiety, panic, and traumatic intrusions were relatively small. CONCLUSION: Results suggest that Deprexis can produce symptomatic improvement among depressed adults recruited from the United States. Additional research is needed that examines whether improvements are maintained over time and who is particularly likely to respond to this form of treatment. (PsycINFO Database Record

Functional role of frontal alpha oscillations in creativity.

Creativity, the ability to produce innovative ideas, is a key higher-order cognitive function that is poorly understood. At the level of macroscopic cortical network dynamics, recent electroencephalography (EEG) data suggests that cortical oscillations in the alpha frequency band (8-12 Hz) are correlated with creative thinking. However, whether alpha oscillations play a functional role in creativity has remained unknown. Here we show that creativity is increased by enhancing alpha power using 10 Hz transcranial alternating current stimulation (10 Hz-tACS) of the frontal cortex. In a study of 20 healthy participants with a randomized, balanced cross-over design, we found a significant improvement of 7.4% in the Creativity Index measured by the Torrance Test of Creative Thinking (TTCT), a comprehensive and most frequently used assay of creative potential and strengths. In a second similar study with 20 subjects, 40 Hz-tACS was used instead of 10 Hz-tACS to rule out a general "electrical stimulation" effect. No significant change in the Creativity Index was found for such frontal 40 Hz stimulation. Our results suggest that alpha activity in frontal brain areas is selectively involved in creativity; this enhancement represents the first demonstration of specific neuronal dynamics that drive creativity and can be modulated by non-invasive brain stimulation. Our findings agree with the model that alpha recruitment increases with internal processing demands and is involved in inhibitory top-down control, which is an important requirement for creative ideation.

Endogenous cortical oscillations constrain neuromodulation by weak electric fields.

BACKGROUND: Transcranial alternating current stimulation (tACS) is a non-invasive brain stimulation modality that may modulate cognition by enhancing endogenous neocortical oscillations by application of sine-wave electric fields. Yet, the role of endogenous network activity in enabling and shaping the effects of tACS has remained unclear. OBJECTIVE: We combined optogenetic stimulation and multichannel slice electrophysiology to elucidate how the effect of a weak sine-wave electric field depends on the ongoing cortical oscillatory activity. We hypothesized that endogenous cortical oscillations constrain neuromodulation by tACS. METHODS: We studied the effect of weak sine-wave electric fields on oscillatory activity in mouse neocortical slices. Optogenetic control of the network activity enabled the generation of in vivo-like cortical oscillations for studying the temporal relationship between network activity and sine-wave electric field stimulation. RESULTS: Weak electric fields enhanced endogenous oscillations but failed to induce a frequency shift of the ongoing oscillation for stimulation frequencies that were not matched to the endogenous oscillation. This constraint on the effect of electric field stimulation imposed by endogenous network dynamics was limited to the case of weak electric fields targeting in vivo-like network dynamics. Together, these results suggest that the key mechanism of tACS may be enhancing, but not overriding, intrinsic network dynamics. CONCLUSION: Our results contribute to understanding the inconsistent tACS results from human studies and propose that stimulation precisely adjusted in frequency to the endogenous oscillations is key to rational design of non-invasive brain stimulation paradigms.