Treatment Strategy to Prevent Mood Disorders Following Traumatic Brain Injury

Following the DSM-IV (now updated by the DSM-5), depressive disorders associated with TBI are categorized as Mood Disorder Due to Another Medical Condition with subtypes: 1) With major depressive-like episode (if the full criteria for a major depressive episode \[MDE\] are met) or 2) With depressive features (prominent depressed mood but full criteria for a MDE are not met); and 3) with mixed features (e.g. significant irritability, pressured speech and formal thought disorder). On the other hand, bipolar and related disorders due to TBI are subdivided in: 1) with manic or hypomanic like episode; 2) with manic features; and 3) with mixed features. A similar conceptual framework has been used to define Anxiety Disorder due to another Medical Condition, in this case, TBI. According to DSM-IV/DSM-5, such diagnosis can be made when, besides an evident pathophysiological relationship with TBI, panic attacks or generalized anxiety are the prominent features of the clinical presentation.

Time frame: 6 months after TBI

The Iowa Gambling Task (IGT) evaluates decision making ability. During IGT subjects have to choose between decks of cards which yield high immediate gain but larger future loss (i.e., long term loss), and decks which yield lower immediate gain but a smaller future loss (i.e., a long term gain). The task consists of four decks of cards: A, B, C, and D. The goal in the task is to maximize profit. Subjects are required to make a series of card selections. The decks A and B are long term loss decks and the decks C and D are long term gain decks. The IGT Score reported is the combination of the raw score for each deck combined in the following way: (C+D) - (A+B). The range for this score is: -100 to 100. Higher values of this score indicate better decision making ability.

Time frame: 6 months after TBI

Population: Out of the 80 participants who completed the trial, only 64 completed IGT at this evaluation time.

This outcome measures memory function and is a composite of five standardized scores: Brief Visuospatial Memory Test - Revised, Delayed Recall and California Verbal Learning Test, Short Delay Free Recall Number Correct and Discriminability, and Long Delay Free Recall Number Correct and Discriminability. Standardized scores (i.e., z-scores) for each test of this composite were obtained by subtracting the mean raw score of all participants to the raw score of each participant and dividing the result by the standard deviation of the raw scores of all participants. The composite score was obtained by averaging the z-scores of the four memory tests mentioned previously. Range: -3 to 3. Higher scores represent better memory function.

Time frame: 6 months following traumatic brain injury

Population: Out of the 80 participants who completed the trial, only 61 completed all the tests necessary to calculate the composite score at this evaluation time.

FA is a measured obtained from Diffusion Tensor Imaging, an image modality of Magnetic Resonance Imaging (MRI). FA is a unitless index. Range: 0 to 1. FA describes the degree of anisotropy of a diffusion process. A value of zero means that diffusion is unrestricted or equally restricted in all directions. A value of one means that diffusion occurs only along one axis and is fully restricted along all other directions. In the context of this study, FA measures the integrity of the cingulate gyrus white matter. Higher FA values reflect higher integrity of the cingulate gyrus white matter tract. Average FA values for the right and left cingulate gyri were summed. One aim of this project was to identify predictors of the occurrence of mood disturbances during the first 6 months following TBI. The hypothesis for this aim was that patients who develop a mood or anxiety disorder six months after TBI present at baseline with lower FA of the cingulate gyrus than those who do not.

Time frame: Baseline

Population: Of the 94 participants randomized, only 61 participants had an MRI and were included in the analysis of this study aim.

The Social Functioning Examination (SFE) is a semi-structured interview that measures social functioning in areas such as interpersonal relationships, work adjustment, use of community resources and satisfaction with living environment. Range: 0 to 1. Higher scores denote lower levels of social functioning.

Time frame: 6 months after TBI

Population: Out of the 80 participants who completed the trial, only 63 completed SFE at this evaluation time.

The Community Integration Questionnaire (CIQ) is intended as a brief, reliable measure of an individual's level of integration into the home and community following traumatic brain injury. Total CIQ scores were used as the outcome measure. Range: 0 to 25. Higher scores indicate higher levels of integration into the home and community following TBI.

Time frame: 6 months after TBI

Population: Out of the 80 participants who completed the trial, only 68 completed CIQ at this evaluation time.