BackgroundCognitive deficits are a substantial burden in clinical depression. The present study considered dysfunction in the right-hemispheric attention network in depression, examining alertness and visuospatial attention.MethodsThree computerized visuospatial attention tests and an alertness test were administered to 16 depressive patients and 16 matched healthy controls.ResultsAlthough no significant group effect was observed, alertness predicted reduced visuospatial performance in the left hemifield. Furthermore, sad mood showed a trend towards predicting left visual field omissions.ConclusionsDecreased alertness may lead to lower left hemifield visuospatial attention; this mechanism may be responsible for a spatial bias to the right side in depression, even though treatment of depression and anxiety may reduce this cognitive deficit.

We present a 66-year-old female with a bipolar-I disorder diagnosis, euthymic on lithium for 41 years. Her past medical history included hypothyroidism (stable on levothyroxine), essential hypertension (controlled on carvedilol), hypercholesterolemia (on lovastatin), anemia, lumbar disc disease, osteopenia, and recurrent urinary tract infections. She gradually developed CKD stage IIIB (GFR 31-39 mL/ min/1.73 m 2 ). Her known risk factors for CKD were hypertension, hypothyroidism, and chronic lithium therapy. After an episode of acute renal failure, lithium was discontinued due to concerns regarding progression toward ESRD. Her treatment response assessment evaluated by the Alda scale prior to discontinuation was 9, but rapidly declined to 1-2. The Alda scale is a standardized scale used to measure longterm treatment response in subjects with BD. 1 Alda score is derived from the scores on two subscales, namely the A scale score (measures the change in illness severity following the introduction of treatment) minus the B scale score (this is used to establish whether there is a causal relationship between clinical improvement and the treatment). 1In the next 18 months, she tried different atypical antipsychotics (lurasidone, aripiprazole, and ziprasidone) with mild improvement (Alda A score = 3), but developed Parkinsonian symptoms. She had a poor response to antidepressants/anxiolytics (venlafaxine, bupropion, and buspirone). Lamotrigine and modafinil were tried but caused a skin rash. She had a mild response to a combination of valproate and desipramine (Alda A score = 3). The patient was not interested in other treatment modalities such as electroconvulsive therapy due to cognitive concerns. She continued weekly/bi-weekly cognitive behavioral therapy and regular exercise. Her depression remained refractory despite several trials of FDA-approved treatments for BD and poor/minimal response to the off-label use of several additional agents. Due to persistent depression and prior history of excellent response to lithium, it was decided to carefully reinitiate lithium while monitoring her renal function. At this time, she was on a combination of buspirone, valproate, and desipramine. Lithium carbonate was initiated at 150 mg daily and the dose was optimized to 300 mg daily. Desipramine and buspirone were gradually tapered.The patient experienced intention tremors and gait instability at a lithium level of 0.6 mEq/L. The valproate was tapered off and led to an improvement of her gait. Within 4-6 weeks of reinitiating lithium therapy, her depression improved significantly (Alda A score = 9).Self-assessment of the patient's mood via the mood scale (10 being the best mood she ever had [euthymia] and 0 the worst mood) found significant improvement after reinitiating lithium. Her mood change using the simple mood scale correlated well with the change in Alda A scores. The patient's renal function tests were checked monthly after reinitiating lithium, and her GFR remained stable between 37-40 mL/ml at 12 months. | D ISCUSS ...

Hemodynamic mismatch responses can be elicited by deviant stimuli in a sequence of standard stimuli even during cognitive demanding tasks. Emotional context is known to modulate lateralized processing. Right-hemispheric negative emotion processing may bias attention to the right and enhance processing of right-ear stimuli. The present study examined the influence of induced mood on lateralized pre-attentive auditory processing of dichotic stimuli using functional magnetic resonance imaging (fMRI). Faces expressing emotions (sad/happy/neutral) were presented in a blocked design while a dichotic oddball sequence with consonant-vowel (CV) syllables in an event-related design was simultaneously administered. Twenty healthy participants were instructed to feel the emotion perceived on the images and to ignore the syllables. Deviant sounds reliably activated bilateral auditory cortices and confirmed attention effects by modulation of visual activity. Sad mood induction activated visual, limbic and right prefrontal areas. A lateralization effect of emotion-attention interaction was reflected in a stronger response to right-ear deviants in the right auditory cortex during sad mood. This imbalance of resources may be a neurophysiological correlate of laterality in sad mood and depression. Conceivably, the compensatory right-hemispheric enhancement of resources elicits increased ipsilateral processing.

The auditory mismatch responses are elicited in absence of directed attention but are thought to reflect attention modulating effects. Little is known however, if the deviants in a stream of standards are specifically directing attention across modalities and how they interact with other attention directing signals such as emotions. We applied the well-established paradigm of left- or right-lateralized deviant syllables within a dichotic listening design. In a simple target detection paradigm with lateralized visual stimuli, we hypothesized that responses to visual stimuli would be speeded after ignored auditory deviants on the same side. Moreover, stimuli with negative valence in the visual domain could be expected to reduce this effect due to attention capture for this emotion, resulting in speeded responses to visual stimuli even when attention was directed to the opposite side by the auditory deviant beforehand. Reaction times of 17 subjects confirmed the speeding of responses after deviant events. However, reduced facilitation was observed for positive targets at the left after incongruent deviants, i.e., at the right ear. In particular, significant interactions of valence and visual field and of valence and spatial congruency emerged. Pre-attentive auditory processing may modulate attention in a spatially selective way. However, negative valence processing in the right hemisphere may override this effect. Resource allocation such as spatial attention is regulated dynamically by multimodal and emotion information processing.