This study investigates the influence of two different insulin regimens, twice-daily insulin lispro low mix (LM) and once-daily insulin glargine, on perceived physical, mood, and cognitive symptoms as well as cognitive-motor task performance in patients with type 2 diabetes.

Inclusion Criteria:

• Diagnosed as having type 2 diabetes mellitus, as defined by the World Health Organization
• Are being treated with metformin therapy alone, metformin therapy plus once-daily insulin, or metformin plus one or more other oral antihyperglycemic agents at the time of study entry
• Female patients not breastfeeding and female patients of childbearing potential must test negative for pregnancy at time of study entry based on a urine pregnancy test and do not intend to become pregnant during the study and agree to use a reliable form of birth control during the study
• Hemoglobin A1c greater than or equal to 7.0% and less than or equal to 10% within 3 months prior to visit 1
• Have given informed consent to participate in the study in accordance with local regulations

Exclusion Criteria:

• Are investigator site personnel directly affiliated with the study, or are immediate family of investigator site personnel directly affiliated with the study.
• Have received treatment within the last 30 days with a drug that has not received regulatory approval for any indication at the time of study entry
• Have previously been diagnosed with clinical depression or have been treated with a central nervous system stimulant, antidepressant, antipsychotic, or anxiolytic agent within 30 days prior to study entry
• Have a known allergy to insulin lispro low mixture, insulin glargine, metformin hydrochloride, or excipients contained in these products
• Have known hypersensitivity or contraindication to metformin hydrochloride