Determinants of Subjective Memory Complaints in Community-dwelling Adults with Traumatic Brain Injury Esther Bay, PhD; Bruno Giordani, PhD; Claire Kalpakjian, PhD The University of Michigan, Ann Arbor, MI l SMC were significantly associated with: l Increased age; l Increased time-since-injury; l Worse self-reported chronic stress; l Heightened somatic symptoms and communication difficulties. l SMC were not associated with: l Motor complaints; l Depressive symptoms. Results Acknowledgements Individuals (N = 159) aged years, who sustained mild-to-moderate TBI and had been evaluated by a neuropsychologist with brain injury expertise, were recruited from outpatient rehabilitation clinics affiliated with tertiary urban trauma facilities. The eligibility criteria included:  Ability to speak English;  No psychosis at the time of their neuropsychological evaluation;  Absence of severe TBI;  No pre-injury neurological impairment such as stroke, Alzheimer’s or Parkinson’s disease. After being consented, and demographic information collected, study participants were placed in a room free of interruptions where written questionnaires were completed with assistance of trained research aides. Instruments used included:  Perceived Stress Scale-14 (PSS-14)  Center for Epidemiological studies-Depression (CES-D)  Neurobehavioural Functioning Inventory (NFI)  Glasgow Coma Scale (GCS) This study used an observational, cross-sectional design. Methods Introduction Difficulties with memory, attention, arousal, speed of information processing, and planning are common and a frustrating consequence of traumatic brain injury (TBI). When they persist, they contribute to chronic stress and negative outcomes. Chronic subjective memory complaints (SMC) have been associated with organic changes, malingering, expectancy, post-concussion syndrome, and depression following less than severe TBI. The purpose of this study, conducted with persons who sustained mild-to-moderate traumatic brain injury (TBI) while in a chronic phase of their recovery and referred for out- patient rehabilitation therapy, was to determine the extent to which chronic subjective memory complaints (SMC) was associated with chronic stress, depression and the neurobehavioral consequences of TBI. The extent to which pre- morbid (sex, education, co-morbidities, employment or marital status) or injury-related covariates, such as time-since-injury, Glasgow Coma Scale (GCS) score (mild vs moderate), or litigation status affected these relationships was examined. The following hypotheses were tested: 1.Compared to younger persons with mild-to- moderate TBI, older adults will have increased SMC, after controlling for related covariates. 2.The effect of age on the positive and significant relationship between chronic stress and SMC will be determined by interactions between age group and depression group severity. 3.Increased levels of SMC will be associated with increased age, time-since-injury, chronic stress, somatic and depressive symptoms. Hypothesis 1:  Older persons (40-60 yrs) showed significantly greater frequencies of SMC than younger (< 40 yrs) persons showed.  Time-since-injury showed a significant main effect on SMC, not premorbid psychiatric history. Implications of Findings This project was supported by an award (T32 HD007422) from the Eunice Kennedy Shriver National Institute of Child Health & Human Development to Dr. Denise Tate. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of Child Health & Human Development, NIH. Study Variables by Age Variables (M, SD) Younger < 40 yrs, n = 81 Older > 40, n = 78 CES-D total20.80 (13.04)21.00 (12.62) PSS (8.91)26.13 (26.12) NFI-Cognition45.11 (15.48)53.41 (14.81)** NFI –Somatic23.01 (23.01)24.22 (7.54) NFI-Depression30.72 (10.88)31.77 (10.61) NFI-Communication22.96 (8.11)25.91 (8.37)* NFI-Motor17.65 (6.65)21.10 (6.48)** Pain severity1.03 (1.93)1.45 (1.82) Time since injury (in months)10.13 (8.69)14.90 (10.05)** *p <.p5; **p <.01 Hypothesis 2:  There were no significant group differences in depression severity.  Using ANOVA and the CES-D cut-off score for depression, SMC was significantly explained by increased age, chronic stress, time-since- injury, as well as the presence of mental health history and the severity group of depressive symptoms (adjusted R 2 = 53%). Hypothesis 3:  SMC was explained by premorbid psychiatric history and increased age, time-since-injury, chronic stress, somatic symptoms, and communication difficulties.  Importantly, depressive symptoms were not associated with SMC. Final Model and Results of Hypothesis 3 ModelVariablesSRC*T-statisticSignificance 1Age Time-since-injury Psychiatric history Age Time-since-injury Psychiatric history NS NFI-Cognition NFI-Motor NS NFI-Somatic NFI-Depression NS Chronic stress (PSS-14) NFI-Communication Adjusted R 2 =.783, F = (df = 8,150), p <.001. Standard regression coefficient (SRC)*.