Psychiatric symptoms of patients with primary mitochondrial DNA disorders

Gabriella Inczedy-Farkas,Zsofia Varga,Benjamin Bereznai,Viktoria Remenyi,Aniko Gal,Agnes Udvardy-Meszaros,Petra Balla,Maria Judit Molnar

doi:10.1186/1744-9081-8-9

Gabriella Inczedy-Farkas, Zsofia Varga + Show 6 more

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https://doi.org/10.1186/1744-9081-8-9

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Abstract

BackgroundThe aim of our study was to assess psychiatric symptoms in patients with genetically proven primary mutation of the mitochondrial DNA.Methods19 adults with known mitochondrial mutation (MT) have been assessed with the Stanford Health Assessment Questionnaire 20-item Disability Index (HAQ-DI), the Symptom Check List-90-Revised (SCL-90-R), the Beck Depression Inventory-Short Form (BDI-SF), the Hamilton Depression Rating Scale (HDRS) and the clinical version of the Structured Clinical Interview for the the DSM-IV (SCID-I and SCID-II) As control, 10 patients with hereditary sensorimotor neuropathy (HN), harboring the peripheral myelin protein-22 (PMP22) mutation were examined with the same tools.ResultsThe two groups did not differ significantly in gender, age or education. Mean HAQ-DI score was 0.82 in the MT (range: 0-1.625) and 0.71 in the HN group (range: 0-1.625). Level of disability between the two groups did not differ significantly (p = 0.6076). MT patients scored significantly higher on the BDI-SF and HDRS than HN patients (12.85 versus 4.40, p = 0.031, and 15.62 vs 7.30, p = 0.043, respectively). The Global Severity Index (GSI) of SCL-90-R also showed significant difference (1.44 vs 0.46, p = 0.013) as well as the subscales except for somatization. SCID-I interview yielded a variety of mood disorders in both groups. Eight MT patient (42%) had past, 6 (31%) had current, 5 (26%) had both past and current psychiatric diagnosis, yielding a lifetime prevalence of 9/19 (47%) in the MT group. In the HN group, 3 patients had both past and current diagnosis showing a lifetime prevalence of 3/10 (30%) in this group. SCID-II detected personality disorder in 8 MT cases (42%), yielding 3 avoidant, 2 obsessive-compulsive and 3 personality disorder not otherwise specified (NOS) diagnosis. No personality disorder was identified in the HN group.ConclusionsClinicians should be aware of the high prevalence of psychiatric symptoms in patients with mitochondrial mutation which has both etiologic and therapeutic relevance.

Highlights

The aim of our study was to assess psychiatric symptoms in patients with genetically proven primary mutation of the mitochondrial DNA
In the case of Patient 19 - beside the A2706G polymorphism which is responsible for linezolid-induced severe lactic acidosis - 14 single nucleotide polymorphisms associated with Leber Hereditary Optic Neuropathy (LHON) were present potentially exerting synergistic effect
Past or current major depressive disorder, dysthymia, bipolar II and adjustment disorder with depressed mood occurred in 2 MT cases while the past or current diagnosis of major depression with psychotic features, bipolar I, mixed anxiety-depressive disorder, postpartum depression and PTSD was explored in 1 MT case

Summary

Introduction

The aim of our study was to assess psychiatric symptoms in patients with genetically proven primary mutation of the mitochondrial DNA. Mitochondrial disorders are metabolic conditions with chronic deterioration and multiple organ involvement. Primary mutations of the mitochondrial DNA (mtDNA) are inherited maternally while mitochondrial diseases due to mutations in nuclear DNA are transmitted as mendelian traits. Brain tissue depends to a large extent on mitochondrial function for its metabolism, including the maintenance of the transmembrane potential [5], calcium homeostasis [6], signal transduction [7] and synaptic plasticity [8]. Impairments in oxidative phosphorylation tend to manifest in neurologic, psychiatric or neuropsychologic symptomatology [9]

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