A 14 Week, Randomized, Placebo-Controlled Cross-Over Study of Methylphenidate Hydrochloride Controlled Release Capsules in Adult ADHD With and Without Anxiety Disorder Comorbidity

Inclusion Criteria:

1. Outpatient men and women between 18 and 65 years who meet criteria for Current DSM-5ADHDalone or with one of the following DSM-5 diagnoses: GAD, SAD,PD or Agoraphobia.Major Depressive Disorder or Persistent Depressive Disorder will be allowed, providingthe severity is considered moderate or less, as defined by a score on the MontgomeryDepressive Rating Scale-MADRS score of ≤ 25.
2. ADHD rating scale for DSM-5 (ADHD-5-RS) score ≥ 24.
3. Concomitant treatment with selective serotonin reuptake inhibitors (SSRI's), serotoninnoradrenaline reuptake inhibitors (SNRI's), benzodiazepines, beta-blockers, atypicalanti-psychotics, anti-epileptics is allowed, provided the dose has been stable for 8weeks prior to study entry. Dose changes of allowed concomitant medication should beavoided during the treatment phases of the study.
4. The ability to comprehend and satisfactorily comply with protocol requirements.
5. Written informed consent given prior to entering the baseline period of the study.
6. All women of child bearing potential must have a negative screening visit serum orurine pregnancy test and be using adequate contraception for the duration of thestudy. Medically acceptable forms of contraception include oral contraceptives,injectable or implantable methods, intrauterine devices or properly used barriercontraception. Additionally, the use of condoms is suggested as an adjunct to themethods previously addressed to provide additional protection against accidentalpregnancy.

Exclusion Criteria:

1. Participants who currently fulfill criteria for a lifetime history of bipolardisorder, schizophrenia or other psychotic disorders, delirium, dementia and amnesicand other cognitive disorders, severe head injury, autism spectrum disorders, or arein a current agitated state.
2. Participants with a history of seizure disorders, or an unstable medical conditionwill also be excluded.
3. Participants with significant suicidal ideation (MADRS item 10 score > 3) or who haveenacted suicidal behaviours within 6 months prior to intake will be excluded fromstudy participation and referred for appropriate clinical intervention.
4. Current treatment with a stimulant.
5. A history of > 2 failed trials of adequately dosed psychostimulants for Adult ADHD.
6. Patients receiving current psychotherapy, including cognitive behavioural therapy foreither ADHD or an anxiety disorder, within 4 weeks prior to the baseline period.
7. Patients who are known to be allergic to methylphenidate or components ofmethylphenidate hydrochloride, have known hypersensitivity or idiosyncrasy tomethylphenidate hydrochloride.
8. Patients who have thyroid pathology, treatment of which has not been stabilized for atleast 3 months.
9. MAO inhibitors within 3 weeks of the start of the baseline.
10. Individuals meeting criteria for current cannabis use disorder or substance usedisorder will be excluded.
11. Current use of bupropion or tri-cyclic antidepressants, with the exception ofclomipramine.
12. Current use of clonidine, modafinil or atomoxetine.
13. Previous intolerance or failure to respond to an adequate trial of methylphenidatehydrochloride controlled release capsules (defined as a minimum of 55mg per day for atleast 4 weeks).
14. Patients who have a history or evidence of a medical condition that would expose themto an increase or significant adverse event or interfere with assessments of safetyand efficacy during the course of the trial including: advanced arteriosclerosis,symptomatic cardiovascular disease, moderate to severe hypertension, or otherpre-existing cardiac abnormalities or other serious cardiac problems.
15. Patients with a history of Glaucoma.
16. Sleep medications during the study period are excluded with the exception of zopicloneand zolpidem and melatonin.
17. Patients using any herbal psychoactive treatments, eg; St.John's Wort, Valerian, KavaKava, or Chamomile Extract within 14 days prior to randomization.
18. Patients who have received electroconvulsive therapy within the previous 6 months.
19. Patients with any condition or on any therapy that in the investigator's opinion or asindicated in the methylphenidate hydrochlorideproduct label, that may pose a risk tothe subject or interfere with the study objective.
20. Patients having clinically significant abnormal laboratory or ECG findings notresolved by the baseline examination.
21. Patients with a proximal family history of sudden, unexplained cardiac death.