This two-site randomized clinical trial will investigate and compare three treatments for insomnia in patients who have been diagnosed with and treated for sleep apnea: online cognitive behavioral therapy (OCBT), therapist-directed cognitive behavioral therapy (TCBT), and standard clinical care. 384 patients will be recruited and will attend up to 15 visits over 10 months. Visits will include baseline assessment, treatment visits, and post-treatment follow-up visits. Visits will involve completion of questionnaires, meeting with therapists, and a physical exam.

This dual-site randomized clinical trial will use a "SMART" design to test a stepped care model relative to standard positive airway pressure (PAP) therapy and determine if (1) augmentation of PAP therapy with online Cognitive Behavioral Therapy improves short-term outcomes of comorbid obstructive sleep apnea(OSA)/insomnia; and (2) providing a higher intensity 2nd-stage cognitive behavioral therapy (CBT) to patients who show sub-optimal short-term outcomes with OCBT+PAP improves short and longer-term outcomes. After completing baseline assessment, the 384 comorbid OSA\insomnia patients enrolled will be randomized to a 1st-stage therapy that includes usual care PAP + OCBT (n=288) or UC (usual care PAP + sleep hygiene education; n=96). Insomnia and OSA will be reassessed after 8 weeks. OCBT recipients who meet "remission" criteria will continue PAP but be offered no additional insomnia intervention and will complete study outcome measures again after an additional 8-weeks and at 3 and 6 month follow-ups. OCBT recipients classified as "unremitted" after 8 weeks of treatment will be re-randomized to a 2nd-stage treatment consisting of continued, expanded engagement in OCBT or a switch to therapist-directed CBT (TCBT). Those receiving the 2nd-stage intervention as well as the UC group will be reassessed after another 8 weeks and at 3- and 6-month follow-up time points.

Inclusion Criteria:

To be included participants must > 21 years old and:

1. have a diagnosis of OSA with an AHI > 5 on a diagnostic polysomnogram;
2. accept PAP as primary/sole OSA therapy, been given a prescription for PAP and filled it within the last 3 months, have had an opportunity to use PAP for at least one month, and show mean use of > 1 hour per night;
3. have a complaint of persistent (i.e., > 3 months) sleep onset or sleep maintenance difficulties despite having adequate opportunity for sleep and accompanied by significant daytime impairment or distress about poor sleep;
4. an Insomnia Severity Index (ISI) score > 10 indicating at least "mild" insomnia; and
5. a sleep onset latency or wake time after sleep onset > 30 minutes 3 or more nights per week during two weeks of sleep diary monitoring.

Exclusion Criteria:

1. an untreated psychiatric disorder (e.g., major depression) found on structured interviews as these conditions have specific treatments and it would be inappropriate not to offer those treatments;
2. a lifetime diagnosis of any psychotic or bipolar disorder as sleep restriction for insomnia may precipitate hallucinations and mania;
3. an imminent risk for suicide;
4. alcohol or drug abuse within the past year;
5. terminal illness (e.g., cancer), or neurological degenerative disease (e.g., dementia);
6. current use of medications known to cause insomnia (e.g., stimulants);
7. comorbid narcolepsy, idiopathic hypersomnia, restless legs syndrome (score of >11 in the IRLS), periodic limb movement during sleep (known PLMS with arousal > 15 per hour), or a circadian rhythm sleep disorder if habitual bedtimes are later than 3:00 AM or rising times are later than 11:00 AM; or
8. consuming > 2 alcoholic beverages per day on a regular basis; or
9. consuming more than 10 caffeinated beverages per day on a regular basis; or
10. consuming marijuana in any form on a regular basis >1 time per week, or if used after 4:00 p.m; or
11. change in thyroid medication dosage or received a new prescription for thyroid medication 3 months before the screening visit; or
12. physician-diagnosed or self-reported seizure disorder.