Depreciation expense is recorded as an operating expense in the consolidated statements of operations and comprehensive loss and amounted to $0.3 million for the years ended February 28, 2018 and 2017.

In conjunction with the purchase of the building in which the Company previously was a tenant, the Company performed a review of the useful lives of its property, plant and equipment. Building improvements, previously classified as leasehold improvements, have had their useful lives adjusted to 5 years from 3 years. During the year ended February 28, 2018, the Company recorded an adjustment of $8 thousand to reflect the deceleration of the depreciation.