One week later, a different researcher (blind to session 1 testing results) visited the patient for the second testing session. In this session, the patient completed a full neuropsychological testing battery, which took between 60 and 90 min. The researcher who conducted this testing (TC) had many years of experience in administering neuropsychological tests. The MMSE [9] and the MoCA [14] are both screening j6 tools for cognitive impairment that are scored out of 30 and take approximately 10 min to complete. The MMSE includes items on orientation to time and place (10 questions), registration (immediate verbal recall of 3 words), serial subtraction (from 100 by 7s), memory (delayed verbal recall of 3 words), naming (pencil, watch), language (repeat a phrase, follow a written instruction, follow a 3-step command, write a sentence) and drawing (copy a line drawing of overlapping pentagons). The MoCA includes sections on visuospatial/executive function (alternating trail-making, cube copy, clock drawing), naming (lion, rhinoceros, camel), attention (forward and backward digit span, tapping to the letter A, subtracting 7s from 100), language (sentence repetition, letter fluency), abstraction (similarities between train and bicycle, watch and ruler), memory (delayed verbal recall of 5 words) and orientation to time and place (6 questions). As two MoCA tasks (subtracting 7s and orientation questions) overlapped with identical items on the MMSE, these items were tested only once. Mood disorder was also assessed during the first 3-month session; the Hospital Anxiety and Depression Scale (HADS) [20] yielded scores for both anxiety and depressive symptoms. The neuropsychological battery administered in the second session was designed to be similar to those used in previous studies requiring a cognitive criterion standard [21]. Our battery included widely used cognitive tests that have established age-specific norms: the Rey Complex Figure, WAIS-R subtests of block design, digit span and digit symbol, the Hopkins Verbal Learning Test–Revised, the Trail-Making Test, letter and animal fluency, Star Cancellation, the Token Test and the Boston Naming Test. These tasks were grouped into the separate but interdependent domains of Visuospatial, Memory, Executive, Language, Attention and Visual neglect (see Table S1 for full details of the battery). The criterion standard classification of cognitive impairment was determined on the basis of the neuropsychological battery. Scores on each test were translated to z-scores using age- and education-specific normative data. These z-scores were then averaged across the contributing tests within each domain to yield an overall domain z-score. The only exception was the Visual neglect domain, where a standard cut-off of <51 on the Star Cancellation test was used to indicate a deficit [22]. A patient was classified as cognitively impaired if he or she had domain z-scores of <−1 (i.e.