The proposed study involves developing and evaluating an interactive, web-based CBT intervention for OEF/OIF Veterans with hazardous or problematic substance use and PTSD symptoms (PTSD or subsyndromal PTSD). The intervention will address the special culture and experiences of the investigators targeted population (OEF/OIF Veterans). The web-based CBT intervention includes 24 modules, to be used across 24 sessions targeting OEF/OIF Veterans with hazardous or problematic substance use and PTSD symptoms. The investigators ask participants to complete 2 sessions per week (one module per session) for 12 weeks. The first 18 modules to be completed across 18 sessions (9 weeks) are considered core modules relevant to all Veterans in the target population. These modules are designed to reduce posttraumatic stress symptoms as well as reduce and prevent the escalation of problematic substance use. The remaining 6 module topics are considered "optional" and are used based on the interest and clinical need of various sub-groups of VA patients. The study includes initial input as well as feedback on a beta version from experts who have worked with OEF/OIF veterans with PTSD and substance abuse problems as well as input/feedback from the target population (the Veterans themselves). In addition to presenting content grounded in evidence-based CBT interventions, the program also employs state of the art technologies to deliver module content grounded in evidence-based learning principles, including Computer-Assisted Instruction, Computer Simulation and other interactive exercises.

Phase 1: Focus Groups

Inclusion Criteria:

1. At least 18 years of age
2. An OEF or OIF veteran (verified via CPRS)
3. Screen positive on the Audit-C (>=3 for women or >= 4 for men) OR screen positive on the PC-PTSD (>=3).
4. Currently receiving primary medical care at a VA Medical Center (verified via CPRS)

Exclusion Criteria:

1. Insufficient ability to understand or provide informed consent
2. Lack sufficient ability to use English to participate in the consent process,
3. Current plan or intent to harm themselves as measured with the suicide assessment in Appendix D after the consent process.

Phase 2: Feedback Sessions

Inclusion Criteria

1. At least 18 years of age

2. An OEF or OIF veteran (verified via CPRS)

3. Hazardous or harmful substance use as measured by one of the following:

   • AUDIT-C score of >=3 (for women) or >= 4 (for men) OR

   • DAST score of >=2 OR

   • Have exited a controlled environment (e.g., detoxification unit, hospital, or correctional facility) within 30 days of screening AND within 30 days prior to entering the controlled environment report:

     i. heavy drinking (>3 drinks for women or > 4 drinks for men on one or more days), or ii.use of any illegal drugs, iii.or misuse of prescription drugs (use in excess of the directions or any non-medical use)

4. Screen positive on the PC-PTSD (>=2).

5. Currently receiving primary medical care at a VA Medical Center (verified via CPRS)

Exclusion Criteria:

1. Insufficient ability to understand or provide informed consent
2. Lack sufficient ability to use English to participate in the consent process, the computerized intervention or the assessments.
3. Current plan or intent to harm themselves as measured with the suicide assessment in Appendix D administered after the consent process.

Phase 3: Randomized Clinical Trial

Inclusion Criteria:

1. At least 18 years of age

2. An OEF or OIF veteran (verified via CPRS)

3. Hazardous or harmful substance use as measured by one of the following:

   • AUDIT score of >=7 (for women) or >= 8 (for men) OR

   • DAST score of >=2 OR

   • Have exited a controlled environment (e.g., detoxification unit, hospital, or correctional facility) within 30 days of screening AND within 30 days prior to entering the controlled environment report:

     i. heavy drinking (>3 drinks for women or > 4 drinks for men on1 or more days) or ii. use of any illegal drugs iii. misuse of prescription drugs (use in excess of the directions or any non-medical use)

4. Determined to have diagnostic-level or PTSD (1 A symptom, 1 B symptom, 3 C symptoms AND 2 D symptoms) or subthreshold PTSD (1 A symptom, 1 B symptom, 3 C symptoms OR 2 D symptoms) on the Clinician Administered PTSD Scale (CAPS).

5. Currently receiving primary medical care at a VA Medical Center (verified via CPRS)

Exclusion Criteria:

1. Plans to move out of area within the next three months
2. Currently enrolled in a substance abuse treatment program or receiving treatment for PTSD from a mental health professional (verified via CPRS).
3. Insufficient ability to understand or provide informed consent
4. Lack sufficient ability to use English to participate in the consent process, the computerized intervention or the assessments.
5. In need of alcohol detoxification as determined by a score of > 15 on the Clinical Institute Withdrawal Assessment for Alcohol (CIWA-Ar).
6. Current plan or intent to harm themselves as measured with the suicide assessment in Appendix D administered after the consent process.
7. Medical chart diagnosis of a current psychotic disorder, including schizophrenia or bi-polar disorder
8. Cognitive impairment specified by a medical chart diagnosis. Diagnoses include dementia and moderate to severe traumatic brain injury (TBI). Patients with mild TBI will not be excluded. The Second Level TBI Assessment present in patient medical records can be used to verify the severity of TBI.