Addressing Missing Data Mechanism Uncertainty Using Multiple-Model Multiple Imputation: Application to a Longitudinal Clinical Trial.

Addressing Missing Data Mechanism Uncertainty using Multiple-Model Multiple Imputation: Application to a Longitudinal Clinical Trial.

Ann Appl Stat. 2012 Dec 1; 6(4): 1814-1837
Siddique J, Harel O, Crespi CM

We present a framework for generating multiple imputations for continuous data when the missing data mechanism is unknown. Imputations are generated from more than one imputation model in order to incorporate uncertainty regarding the missing data mechanism. Parameter estimates based on the different imputation models are combined using rules for nested multiple imputation. Through the use of simulation, we investigate the impact of missing data mechanism uncertainty on post-imputation inferences and show that incorporating this uncertainty can increase the coverage of parameter estimates. We apply our method to a longitudinal clinical trial of low-income women with depression where nonignorably missing data were a concern. We show that different assumptions regarding the missing data mechanism can have a substantial impact on inferences. Our method provides a simple approach for formalizing subjective notions regarding nonresponse so that they can be easily stated, communicated, and compared. HubMed – depression


Systematic review on the evidences of an association between tinnitus and depression.

Braz J Otorhinolaryngol. 2013 Feb; 79(1): 106-111
Geocze L, Mucci S, Abranches DC, Marco MA, Penido ND

Tinnitus has been associated with several psychiatric disorders, however there are still several questions regarding such association. OBJECTIVE: To assess the scientific evidence on the associations between symptoms of depression, depression, and tinnitus. METHOD: A systematic review was performed using PubMed, Lilacs, and SciELO scientific databases. This review included studies published in Portuguese, Spanish, or English correlating tinnitus with depression; letters to the editor and case reports were excluded. RESULTS: A total of 64 studies were identified, of which only 20 met the inclusion criteria and only 2 were case-control clinical trials. The majority of the studies (n = 18) found that depression is associated with tinnitus, either as a predisposition – resulting in poor adaptation to tinnitus or as a consequence of severe disease. CONCLUSION: An overall assessment of all of the selected studies suggests at least 3 possible associations between depression and tinnitus: depression affecting tinnitus, tinnitus predisposing individuals to depression, and tinnitus appearing as a comorbidity in patients with depression. There is a high prevalence of depressive symptoms in individuals with tinnitus, but the mechanisms by which depression and tinnitus mutually interact, are not fully understood. HubMed – depression


Deep brain stimulation: a return journey from psychiatry to neurology.

Postgrad Med J. 2013 Mar 15;
Ashkan K, Shotbolt P, David AS, Samuel M

Deep brain stimulation (DBS) has emerged as an effective neurosurgical tool to treat a range of conditions. Its use in movement disorders such as Parkinson’s disease, tremor and dystonia is now well established and has been approved by the National Institute of Clinical Excellence (NICE). The NICE does, however, emphasise the need for a multidisciplinary team to manage these patients. Such a team is traditionally composed of neurologists, neurosurgeons and neuropsychologists. Neuropsychiatrists, however, are increasingly recognised as essential members given many psychiatric considerations that may arise in patients undergoing DBS. Patient selection, assessment of competence to consent and treatment of postoperative psychiatric disease are just a few areas where neuropsychiatric input is invaluable. Partly driven by this close team working and partly based on the early history of DBS for psychiatric disorders, there is increasing interest in re-exploring the potential of neurosurgery to treat patients with psychiatric disease, such as depression and obsessive-compulsive disorder. Although the clinical experience and evidence with DBS in this group of patients are steadily increasing, many questions remain unanswered. Yet, the characteristics of optimal surgical candidates, the best choice of DBS target, the most effective stimulating parameters and the extent of postoperative improvement are not clear for most psychiatric conditions. Further research is therefore required to define how DBS can be best utilised to improve the quality of life of patients with psychiatric disease. HubMed – depression



Psychotherapist, Depression Treatment in Cambridge MA 02138 – Kristin Semmelmeyer, Psy.D., is a clinical psychologist in Cambridge, Massachusetts. She treats adults with a range of issues in psychotherapy including Depr…