Atomoxetine and Executive Function in PTSD

Inclusion Criteria: * Veterans ages 18 to 75 with PTSD and AD (CAPS \> 35 for age 18 to 64, CAPS \> 25 for age 65 to 75; CAARS-S:S \> 60) * The cut-score of 25 used for participants age 65 to 75 because lower cut-score has been recommended for older Veterans (Yeager and Magruder, 2014) * ADHD has been recognized as a neurobehavioral impairment in executive function (Brown, 2008) * Veterans with PTSD at this age range are suited for this study because statistically they have fewer confounding variables for this clinical trial, including medical conditions such as hypertension or glaucoma and cognitive impairments such as dementia * Physical health good enough to be able to participate in the study * Competent to give informed consent Exclusion Criteria: * Age younger than 18 or greater than 75 * Age becomes the main risk factor for major neurocognitive disorder, especially after 75 (Sousa et al, 2020) * Known sensitivity to ATX * Presence of disorders that could conceivably be exacerbated by atomoxetine * specifically, narrow angle closure glaucoma, urinary outflow obstruction, hypertension, and neurological disorders, particularly tics and Tourette's syndrome, or a history of epilepsy or seizures * Subjects with major traumatic brain injury (TBI) determined by Ohio State University Traumatic Brain Injury Identification Method (OSU-TBI ID) * However, mild TBI, assessed with OSU-TBI ID and review of record will be allowed to participate in this trial * Use of concomitant medication that could potentially interact with atomoxetine including monoamine oxidase inhibitors (MAOI), antihypertensive medication, or any concomitant medication that is a cytochrome 2D6 (CYP2D6) inhibitor, such as paroxetine, venlafaxine, fluoxetine, because atomoxetine's elimination involves the CYP2D6 system * Subjects who are currently taking psycho-stimulants, other NRIs such as duloxetine, and venlafaxine will be excluded * However, the investigators will allow subjects who stopped the psycho-stimulant or other NRI or other SSRIs 2 weeks prior to the start of the trial * Subjects receiving active ongoing therapy with good response at the point of recruitment * The project will allow approved standard therapies, including psycho- or/and pharmacotherapies be continued with the condition that the subjects continue to present with PTSD symptoms severe enough to meet the inclusion criteria * An active or lifetime major mental health diagnosis as determined by DSM-5 major psychiatric disorders, including: * schizophrenia * schizoaffective disorder * psychotic disorder not otherwise specified * bipolar I disorder, bipolar II disorder * bipolar disorder not otherwise specified * The project will allow the presence of depressive disorders if the depressive episodes are secondary to PTSD * Current substance use disorders: * DSM-5 alcohol * marijuana * and/or other drug use disorders in the last 3 months * Mild alcohol and marijuana use which does not meet the criteria for mild use disorder, such as occasional or recreational use will be permitted on a case by case basis * Females who are pregnant or desired to become pregnant during the clinical trial period * Urine pregnancy tests will be performed at each of the visits, including prior to, during, and after the clinical trial * Prominent suicidal or homicidal ideation or any suicidal behavior in the past 3 months on the Columbia Suicide Severity Rating Scale (C-SSRS)