 We plan to test the effects of adjunctive liraglutide on executive function. We will select a subpopulation of patients, with a mood disorder and impairment in executive function, as defined by a below-average i.e. 1 standard deviation below norm performance in the Trail Making Test-B TMTB. Furthermore, we plan to recruit two groups of patients, with and without insulin resistance, as defined by a homeostatic model assessment for insulin resistance HOMA-IR above 2.5, which will allow a comparison of the effects of liraglutide in a metabolically heterogeneous population. 