Eligibility Criteria:
Inclusion Criteria:
1. Signed written informed consent
2. Between 18-80 years
3. Stroke \>12 months prior to the start of the study. Patients must have had the location of their stroke evaluated through a CT scan, noted in their hospital notes
4. Anamnestic evidence of post stroke residual symptoms at least 3 months prior to the start of the study
5. At least 10.5 points on Mental Fatigue scale at the screening visit 1 (week -2)
Exclusion Criteria:
1. Residual symptoms following other pathologies than stroke
2. Active substance abuse (drug screen taken at visit1)
3. Other serious somatic or psychiatric disease
4. Beck Depression Inventory \>30 at visit1 and 2
5. Current pregnancy or breast-feeding, or intention to become pregnant within 3 months after the last dose
6. Female patients of childbearing potential not using adequate contraceptives. Female patients of childbearing potential must, for inclusion, use a highly efficient method of contraception, i.e. a method with a failure rate of less than 1% (e.g. sterilisation, hormone implants, hormone injections, some intrauterine devices, or vasectomy in partner). Male patients must agree to use condoms during the study and for 2 weeks after the end of the study/last dose of IMP, unless their partner is using a highly efficient method of contraception, as described above.
7. Pathologic ECG, as assessed by the investigator. Max QTc time on ECG: 450 ms in men and 460 ms in women
8. Abnormal laboratory values of such severity that participation in the study, in the opinion of the investigator, is questionable
9. Patients who are so debilitated by their disease that they are not assumed to be able to perform the assessments or handle the instruments used for evaluation of effect
10. Current participation in other Clinical trials
11. Previous treatment with OSU6162
12. Clinically significant liver disease which may prevent the patient from completing the study and/or an elevation in either total bilirubin, alkaline phosphatase, AST, ALT of \>2 times the laboratory reference
13. Clinically significant renal disease which may prevent the patient from completing the study and/or an elevation in serum creatinine of \>1.5 times the laboratory reference.
14. Any surgical or medical condition which, in the opinion of the investigator, might interfere with the absorption, distribution, metabolism or excretion of OSU6162
15. Patients treated with Modiodal, Xyrem, Mirtazapine, Mianserin or metabolic enzyme inhibitors (with the exception of antidepressants other than Mirtazapine and Mianserin) or inducers, or drugs with a narrow treatment window (e.g. warfarin, antiepileptics, cyclosporine) and individually modelled drugs such as lithium.
16. Use of drugs capable of inducing hepatic enzyme metabolism (e.g., barbiturates, rifampicin, carbamazepine, phenytoin, primidone) within 30 days prior to the start of the study (or 5 half-lives of the inducing agent, whichever is longer)
17. Antipsychotic treatment
18. Patients treated with "unstable therapies", i.e., treatments that have not been at the same dose for at least 6 weeks prior to inclusion in this study. The treatment must also remain unchanged during the study period. Insomnia medication and other PRN medications are allowed
19. Use of acute or chronic medications for other medical conditions are allowed based on the investigator's judgement. Occasional use of over-the-counter (OTC) medication is allowed at the investigator's discretion
20. Supplements from health food stores and naturopathic preparations (dietary supplements, natural remedies) are not allowed during the course of the study or 4 weeks before study start.