Finally, duration of follow-up was only 12–16 weeks; a longer follow-up period would be useful to identify long-term effects of GLP-1 receptor agonists on mental health and effects of newer, perhaps more efficacious GLP-1 receptor agonists at higher doses which have since been approved e.g. subcutaneous semaglutide (up to a dose of 2.4 mg weekly), or dual gastric inhibitory polypeptide (GIP)/GLP-1 receptor agonists e.g. tirzepatide, approved for T2D and undergoing appraisal currently by the National Institute for Health and Care Excellence (NICE) for obesity. This evidence concerns the gene GIP and type 2 diabetes mellitus.