Subjects will receive placebo capsules once daily at 10 PM.

Sleep activity is monitored with a 3-axis accelerometer inside the watch device (Misfit Shine), using a general heuristic based on time and motion. The device is waterproof and worn on the wrist 24 hrs per day. Data are downloaded to smartphone via Bluetooth.

Sleep activity is monitored with a 3-axis accelerometer inside the watch device (Misfit Shine), using a general heuristic based on time and motion. The device is waterproof and worn on the wrist 24 hrs per day. Data are downloaded to smartphone via Bluetooth.

Sleep activity is monitored with a 3-axis accelerometer inside the watch device (Misfit Shine), using a general heuristic based on time and motion. The device is waterproof and worn on the wrist 24 hrs per day. Data are downloaded to smartphone via Bluetooth.

Sleep activity is monitored with a 3-axis accelerometer inside the watch device (Misfit Shine), using a general heuristic based on time and motion. The device is waterproof and worn on the wrist 24 hrs per day. Data are downloaded to smartphone via Bluetooth.

Sleep activity is monitored with a 3-axis accelerometer inside the watch device (Misfit Shine), using a general heuristic based on time and motion. The device is waterproof and worn on the wrist 24 hrs per day. Data are downloaded to smartphone via Bluetooth.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the stress subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the stress subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the stress subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the stress subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the stress subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the stress subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the stress subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the anxiety subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the anxiety subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the anxiety subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the anxiety subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the anxiety subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the anxiety subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the anxiety subscale is 0 to 42, with higher scores indicating worse outcome.

The Pittsburg Sleep Quality Index (PSQI) is an 18-item self-report measure of sleep, providing a well-validated and reliable measure of sleep quality, latency, duration, duration efficiency, and disturbance, and an overall summary. The overall summary score will be reported for this measure. The PSQI has been used in several studies of individuals with SUD, including cocaine. Total score ranges from 0-21, with a higher score indicating worse outcome.

Cold Pressor Test (CPT) reliably increases activity of the sympathetic nervous system and the HPA axis, and produces reliable increases in heart rate and cortisol. Subjects are requested to submerge the dominant arm up to the wrist or elbow in ice-cold water (0° to 4° C) for as long as possible with a maximum of 90 seconds. The procedure activates afferent nerves and elicits a CNS stress response. This procedure produces no lasting biological or psychological distress beyond the acute challenge period, and physiological effects return to baseline within 90 min. In fact, the CPT is used to study pain in children, and is considered a noninvasive, exempt educational experimental activity by the IRB of the University of Texas-Austin. It has been used extensively in cardiology, endocrinology, psychiatry, and psychology since 1940 as a challenge to the peripheral and central stress axis

Cold Pressor Test (CPT) reliably increases activity of the sympathetic nervous system and the HPA axis, and produces reliable increases in heart rate and cortisol. Subjects are requested to submerge the dominant arm up to the wrist or elbow in ice-cold water (0° to 4° C) for as long as possible with a maximum of 90 seconds. The procedure activates afferent nerves and elicits a CNS stress response. This procedure produces no lasting biological or psychological distress beyond the acute challenge period, and physiological effects return to baseline within 90 min. In fact, the CPT is used to study pain in children, and is considered a noninvasive, exempt educational experimental activity by the IRB of the University of Texas-Austin. It has been used extensively in cardiology, endocrinology, psychiatry, and psychology since 1940 as a challenge to the peripheral and central stress axis.

Cold Pressor Test (CPT) reliably increases activity of the sympathetic nervous system and the HPA axis, and produces reliable increases in heart rate and cortisol. Subjects are requested to submerge the dominant arm up to the wrist or elbow in ice-cold water (0° to 4° C) for as long as possible with a maximum of 90 seconds. The procedure activates afferent nerves and elicits a CNS stress response. This procedure produces no lasting biological or psychological distress beyond the acute challenge period, and physiological effects return to baseline within 90 min. In fact, the CPT is used to study pain in children, and is considered a noninvasive, exempt educational experimental activity by the IRB of the University of Texas-Austin. It has been used extensively in cardiology, endocrinology, psychiatry, and psychology since 1940 as a challenge to the peripheral and central stress axis.

Score provided is the total score (0 to 300) across three items that are each on a 0-100 scale. A higher score indicates greater stress.

Text-based reminders to take the medication will be enabled via using a HIPAA secure texting service (Talksoft ©), used broadly in medical settings. Participants will be prompted each night at 10 PM to take their medication, and instructed to text back "yes" when they have taken their medication.

Total of all reporting groups

The attention bias (AB) task is a saccade-based eye-tracking measurement, developed by the PI to assess attentional bias to drug cues. AB measures utilizing eye movements have produced moderate to robust effects for a broad class abused substances, including cocaine. The score ranges from 0 to 1. Higher scores indicate a worse outcome.

Data were not collected for one in the suvorexant arm and one in the placebo arm.

The attention bias (AB) task is a saccade-based eye-tracking measurement, developed by the PI to assess attentional bias to drug cues. AB measures utilizing eye movements have produced moderate to robust effects for a broad class abused substances, including cocaine. The score ranges from 0 to 1. Higher scores indicate a worse outcome.

Data were not collected for one in the placebo arm.

Sleep activity is monitored with a 3-axis accelerometer inside the watch device (Misfit Shine), using a general heuristic based on time and motion. The device is waterproof and worn on the wrist 24 hrs per day. Data are downloaded to smartphone via Bluetooth.

Data were not collected for one in the suvorexant arm and 5 in the placebo arm.

Sleep activity is monitored with a 3-axis accelerometer inside the watch device (Misfit Shine), using a general heuristic based on time and motion. The device is waterproof and worn on the wrist 24 hrs per day. Data are downloaded to smartphone via Bluetooth.

Data were not collected for 2 in the suvorexant arm and 4 in the placebo arm.

Sleep activity is monitored with a 3-axis accelerometer inside the watch device (Misfit Shine), using a general heuristic based on time and motion. The device is waterproof and worn on the wrist 24 hrs per day. Data are downloaded to smartphone via Bluetooth.

Data were not collected for 4 in the suvorexant arm and 4 in the placebo arm.

Sleep activity is monitored with a 3-axis accelerometer inside the watch device (Misfit Shine), using a general heuristic based on time and motion. The device is waterproof and worn on the wrist 24 hrs per day. Data are downloaded to smartphone via Bluetooth.

Data were not collected for one in the suvorexant arm and 4 in the placebo arm.

Sleep activity is monitored with a 3-axis accelerometer inside the watch device (Misfit Shine), using a general heuristic based on time and motion. The device is waterproof and worn on the wrist 24 hrs per day. Data are downloaded to smartphone via Bluetooth.

Data were not collected for 2 in the suvorexant arm and 4 in the placebo arm.

Sleep activity is monitored with a 3-axis accelerometer inside the watch device (Misfit Shine), using a general heuristic based on time and motion. The device is waterproof and worn on the wrist 24 hrs per day. Data are downloaded to smartphone via Bluetooth.

Data were not collected for 4 in the suvorexant arm and 4 in the placebo arm.

Sleep activity is monitored with a 3-axis accelerometer inside the watch device (Misfit Shine), using a general heuristic based on time and motion. The device is waterproof and worn on the wrist 24 hrs per day. Data are downloaded to smartphone via Bluetooth.

Data were not collected for 3 in the suvorexant arm and 5 in the placebo arm.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the stress subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the stress subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the stress subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the stress subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the stress subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the stress subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the stress subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the anxiety subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the anxiety subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the anxiety subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the anxiety subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the anxiety subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the anxiety subscale is 0 to 42, with higher scores indicating worse outcome.

DASS21 is a 21-item self-report questionnaire assessing the severity of clinically agreed upon core depression, anxiety, and stress symptoms. It is well validated in multiple languages and countries, and has been utilized in SUD treatment and withdrawal studies. Total score on the anxiety subscale is 0 to 42, with higher scores indicating worse outcome.

The Cocaine Craving Questionnaire (CCQ) Brief is a self-report, 14-item measure with five conceptual domains: Desire to Use, Intention to Use, Anticipation of Positive Outcome, Anticipation of Relief from Dysphoria, and Lack of Control over use. The measure is well validated and has been used in multiple studies of CUD. Total score ranges from 1 to 7. A higher score indicates a worse outcome.

The Pittsburg Sleep Quality Index (PSQI) is an 18-item self-report measure of sleep, providing a well-validated and reliable measure of sleep quality, latency, duration, duration efficiency, and disturbance, and an overall summary. The overall summary score will be reported for this measure. The PSQI has been used in several studies of individuals with SUD, including cocaine. Total score ranges from 0-21, with a higher score indicating worse outcome.

Data were not collected for days 2, 4, 9, and 11. For days 0, 7, and 14, where number analyzed is less than 10, data were not collected for the number that are not reported.

Cold Pressor Test (CPT) reliably increases activity of the sympathetic nervous system and the HPA axis, and produces reliable increases in heart rate and cortisol. Subjects are requested to submerge the dominant arm up to the wrist or elbow in ice-cold water (0° to 4° C) for as long as possible with a maximum of 90 seconds. The procedure activates afferent nerves and elicits a CNS stress response. This procedure produces no lasting biological or psychological distress beyond the acute challenge period, and physiological effects return to baseline within 90 min. In fact, the CPT is used to study pain in children, and is considered a noninvasive, exempt educational experimental activity by the IRB of the University of Texas-Austin. It has been used extensively in cardiology, endocrinology, psychiatry, and psychology since 1940 as a challenge to the peripheral and central stress axis

Cold Pressor Test (CPT) reliably increases activity of the sympathetic nervous system and the HPA axis, and produces reliable increases in heart rate and cortisol. Subjects are requested to submerge the dominant arm up to the wrist or elbow in ice-cold water (0° to 4° C) for as long as possible with a maximum of 90 seconds. The procedure activates afferent nerves and elicits a CNS stress response. This procedure produces no lasting biological or psychological distress beyond the acute challenge period, and physiological effects return to baseline within 90 min. In fact, the CPT is used to study pain in children, and is considered a noninvasive, exempt educational experimental activity by the IRB of the University of Texas-Austin. It has been used extensively in cardiology, endocrinology, psychiatry, and psychology since 1940 as a challenge to the peripheral and central stress axis.

Cold Pressor Test (CPT) reliably increases activity of the sympathetic nervous system and the HPA axis, and produces reliable increases in heart rate and cortisol. Subjects are requested to submerge the dominant arm up to the wrist or elbow in ice-cold water (0° to 4° C) for as long as possible with a maximum of 90 seconds. The procedure activates afferent nerves and elicits a CNS stress response. This procedure produces no lasting biological or psychological distress beyond the acute challenge period, and physiological effects return to baseline within 90 min. In fact, the CPT is used to study pain in children, and is considered a noninvasive, exempt educational experimental activity by the IRB of the University of Texas-Austin. It has been used extensively in cardiology, endocrinology, psychiatry, and psychology since 1940 as a challenge to the peripheral and central stress axis.

Where number analyzed is less than 10, data were not collected for the number that are not reported.

Score provided is the total score (0 to 300) across three items that are each on a 0-100 scale. A higher score indicates greater stress.

Text-based reminders to take the medication will be enabled via using a HIPAA secure texting service (Talksoft ©), used broadly in medical settings. Participants will be prompted each night at 10 PM to take their medication, and instructed to text back "yes" when they have taken their medication.

Subjects will receive placebo once daily at 10 PM.

Placebo (for suvorexant): Subjects will receive placebo capsules once daily at 10 PM.