Differential diagnosis of bipolar disorder and major depressive disorder

AbstractBackgroundPatients with bipolar disorder spend approximately half of their lives symptomatic and the majority of that time suffering from symptoms of depression, which complicates the accurate diagnosis of bipolar disorder.MethodsChallenges in the differential diagnosis of bipolar disorder and major depressive disorder are reviewed, and the clinical utility of several screening instruments is evaluated.ResultsThe estimated lifetime prevalence of major depressive disorder (i.e., unipolar depression) is over 3 and one-half times that of bipolar spectrum disorders. The clinical presentation of a major depressive episode in a bipolar disorder patient does not differ substantially from that of a patient with major depressive disorder (unipolar depression). Therefore, it is not surprising that without proper screening and comprehensive evaluation many patients with bipolar disorder may be misdiagnosed with major depressive disorder (unipolar depression). In general, antidepressants have demonstrated little or no efficacy for depressive episodes associated with bipolar disorder, and treatment guidelines recommend using antidepressants only as an adjunct to mood stabilizers for patients with bipolar disorder. Thus, correct identification of bipolar disorder among patients who present with depression is critical for providing appropriate treatment and improving patient outcomes.LimitationsClinical characteristics indicative of bipolar disorder versus major depressive disorder identified in this review are based on group differences and may not apply to each individual patient.ConclusionThe overview of demographic and clinical characteristics provided by this review may help medical professionals distinguish between major depressive disorder and bipolar disorder. Several validated, easily administered screening instruments are available and can greatly improve the recognition of bipolar disorder in patients with depression

Recent developments in unconventional superconductivity theory

The review of recent developments in the unconventional superconductivity theory is given. In the fist part I consider the physical origin of the Kerr rotation polarization of light reflected from the surface of superconducting $Sr_2RuO_4$. Then the comparison of magneto-optical responses in superconductors with orbital and spin spontaneous magnetization is presented. The latter result is applied to the estimation of the magneto-optical properties of neutral superfluids with spontaneous magnetization. The second part is devoted to the natural optical activity or gyrotropy properties of noncentrosymmetric metals in their normal and superconducting states. The temperature behavior of the gyrotropy coefficient is compared with the temperature behavior of paramagnetic susceptibility determining the noticeable increase of the paramagnetic limiting field in noncentrosymmetric superconductors. In the last chapter I describe the order parameter and the symmetry of superconducting state in the itinerant ferromagnet with orthorhombic symmetry. Finally the Josephson coupling between two adjacent ferromagnet superconducting domains is discussed.Comment: 15 page

Response, relaxation and transport in unconventional superconductors

We investigate the collision-limited electronic Raman response and the attenuation of ultrasound in spin-singlet d-wave superconductors at low temperatures. The dominating elastic collisions are treated within a t-matrix approximation, which combines the description of weak (Born) and strong (unitary) impurity scattering. In the long wavelength limit a two-fluid description of both response and transport emerges. Collisions are here seen to exclusively dominate the relaxational dynamics of the (Bogoliubov) quasiparticle system and the analysis allows for a clear connection of response and transport phenomena. When applied to quasi-2-d superconductors like the cuprates, it turns out that the transport parameter associated with the Raman scattering intensity for B1g and B2g photon polarization is closely related to the corresponding components of the shear viscosity tensor, which dominates the attenuation of ultrasound. At low temperatures we present analytic solutions of the transport equations, resulting in a non-power-law behavior of the transport parameters on temperature.Comment: 22 pages, 3 figure

Can we distinguish anxiety from depression?

It is becoming increasingly apparent that although anxiety and depression are separate syndromes and can be identified as such, there is considerable overlap of clinical symptoms and pathophysiological processes. Data indicate that comorbid anxiety and depression is more common than either disorder alone. A large US study found that 58% of individuals with a history of depression also had an anxiety disorder, and a study by the World Health Organization showed that anxiety and depression were the most common coexisting psychological problems in primary care. Generalized anxiety disorder in particular is strongly comorbid with, and commonly precedes, major depression. The implications of comorbid anxiety and depression are significant, with increased social and psychological impairment, and poorer clinical outcomes and prognosis. Anxiety and depression coexist at much higher rates than would be expected by chance alone, suggesting that the two disorders are closely related and may have a common cause. Disturbances of serotonin and norepinephrine neurotransmission are both implicated in anxiety and depression, and new evidence suggests that these systems may provide a mechanistic link between the two disorders, with changes in one system being reflected in the other. Abnormal homeostasis of these two systems may result in anxiety and depression. New theories hypothesize a continuum of illness, with anxiety and depression possibly being different phenotypic expressions of a common neurobiological origin. There is still uncertainty regarding the neurobiological cause, but it is probably linked to dysregulation in the serotonergic and noradrenergic systems