Predicting states of elevated negative affect in adolescents from smartphone sensors: a novel personalized machine learning approach.

BACKGROUND: Adolescence is characterized by profound change, including increases in negative emotions. Approximately 84% of American adolescents own a smartphone, which can continuously and unobtrusively track variables potentially predictive of heightened negative emotions (e.g. activity levels, location, pattern of phone usage). The extent to which built-in smartphone sensors can reliably predict states of elevated negative affect in adolescents is an open question. METHODS: Adolescent participants (n = 22; ages 13-18) with low to high levels of depressive symptoms were followed for 15 weeks using a combination of ecological momentary assessments (EMAs) and continuously collected passive smartphone sensor data. EMAs probed negative emotional states (i.e. anger, sadness and anxiety) 2-3 times per day every other week throughout the study (total: 1145 EMA measurements). Smartphone accelerometer, location and device state data were collected to derive 14 discrete estimates of behavior, including activity level, percentage of time spent at home, sleep onset and duration, and phone usage. RESULTS: A personalized ensemble machine learning model derived from smartphone sensor data outperformed other statistical approaches (e.g. linear mixed model) and predicted states of elevated anger and anxiety with acceptable discrimination ability (area under the curve (AUC) = 74% and 71%, respectively), but demonstrated more modest discrimination ability for predicting states of high sadness (AUC = 66%). CONCLUSIONS: To the extent that smartphone data could provide reasonably accurate real-time predictions of states of high negative affect in teens, brief 'just-in-time' interventions could be immediately deployed via smartphone notifications or mental health apps to alleviate these states.

Multi-modal assessment of reward functioning in adolescent anhedonia.

BACKGROUND: Anhedonia is a core symptom of depression that predicts worse treatment outcomes. Dysfunction in neural reward circuits is thought to contribute to anhedonia. However, whether laboratory-based assessments of anhedonia and reward-related neural function translate to adolescents' subjective affective experiences in real-world contexts remains unclear. METHODS: We recruited a sample of adolescents (n = 82; ages 12-18; mean = 15.83) who varied in anhedonia and measured the relationships among clinician-rated and self-reported anhedonia, behaviorally assessed reward learning ability, neural response to monetary reward and loss (as assessed with functional magnetic resonance imaging), and repeated ecological momentary assessment (EMA) of positive affect (PA) and negative affect (NA) in daily life. RESULTS: Anhedonia was associated with lower mean PA and higher mean NA across the 5-day EMA period. Anhedonia was not related to impaired behavioral reward learning, but low PA was associated with reduced nucleus accumbens response during reward anticipation and reduced medial prefrontal cortex (mPFC) response during reward outcome. Greater mean NA was associated with increased mPFC response to loss outcome. CONCLUSIONS: Traditional laboratory-based measures of anhedonia were associated with lower subjective PA and higher subjective NA in youths' daily lives. Lower subjective PA and higher subjective NA were associated with decreased reward-related striatal functioning. Higher NA was also related to increased mPFC activity to loss. Collectively, these findings demonstrate that laboratory-based measures of anhedonia translate to real-world contexts and that subjective ratings of PA and NA may be associated with neural response to reward and loss.

Prevalence and correlates of suicidal ideation and suicide attempts in preadolescent children: A US population-based study.

The present study evaluated sociodemographic and diagnostic predictors of suicidal ideation and attempts in a nationally representative sample of preadolescent youth enrolled in the Adolescent Brain Cognitive Development Study. Rates and predictors of psychiatric treatment utilization among suicidal youth also were examined. Eleven thousand eight hundred and seventy-five 9- and 10-year-old children residing in the United States were assessed. Children and their parents/guardians provided reports of children's lifetime history of suicidal ideation, suicide attempts, and psychiatric disorders. Parents also reported on sociodemographic characteristics and mental health service utilization. Multivariate logistic regression analyses were employed to evaluate sociodemographic and diagnostic correlates of suicidal ideation, suicide attempts among youth with suicidal ideation, and treatment utilization among youth with suicidal ideation and suicide attempts. Lifetime prevalence rates were 14.33% for suicidal ideation and 1.26% for suicide attempts. Youth who identified as male, a sexual minority, or multiracial had greater odds of suicidal ideation, and sexual minority youth and youth with a low family income had greater odds of suicide attempts. Comorbid psychopathology was associated with higher odds of both suicidal ideation and suicide attempts. In youth, 34.59% who have suicidal ideation and 54.82% who had attempted suicide received psychiatric treatment. Treatment utilization among suicidal youth was lower among those who identified as female, Black, and Hispanic. Suicidal ideation and attempts among preadolescent children are concerningly high and targeted assessment and preventative efforts are needed, especially for males, racial, ethnic, and sexual minority youth, and those youth experiencing comorbidity.