What do the genetic association data say about the high risk of suicide in people with depression? A novel network-based approach to find common molecular basis for depression and suicidal behavior and related therapeutic targets

J Affect Disord. 2018 Mar 15:229:463-468. doi: 10.1016/j.jad.2017.12.079. Epub 2018 Jan 8.

Abstract

Background: Available sources indicate that the risk of suicide in people with major depression is higher than other psychiatric disorders. Although it seems that these two conditions may have a shared cause in some cases, no studies have been conducted to identify a common basis for them.

Methods: In this study, following an extensive review of literature, we found almost all the genes that are involved in major depression and suicidal behavior, and we isolated genes shared between the two conditions. Then, we found all physical or functional interactions within three mentioned gene sets and reconstructed three genetic interactive networks. All networks were analyzed topologically and enriched functionally. Finally, using a drug repurposing approach, we found the main available drugs that interacted with the most central genes shared between suicidal behavior and depression.

Results: The results demonstrated that BDNF, SLC6A4, CREB1, and TNF are the most fundamental shared genes; and generally, disordered dopaminergic, serotonergic, and immunologic pathways in neuronal projections are the main shared deficient pathways. In addition, we found two genes, SLC6A4 and SLC6A2, to be the main therapeutic targets, and Serotonin-Norepinephrine Reuptake Inhibitors (SNRI) and Tricyclic Antidepressants (TCA) to be the most effective drugs for individuals with depression at risk for suicide.

Conclusions: Our results, in addition to shedding light on the integrated molecular basis of depression-suicide, offer new therapeutic targets for individuals with depression at high risk for suicide and could pave the way for future preclinical and clinical studies. However, integrative systems biology-based studies highly depend on existing data and related databases, as well as the arrival of new experimental data sources in the future, possibly affecting the current results.

Keywords: Drug repurposing; Enrichment analysis; Genetic network; Major depression; Suicidal behavior.

MeSH terms

  • Antidepressive Agents, Tricyclic / therapeutic use*
  • Brain-Derived Neurotrophic Factor / genetics
  • Cyclic AMP Response Element-Binding Protein / genetics
  • Databases, Genetic
  • Depression / drug therapy
  • Depression / genetics*
  • Depression / psychology
  • Depressive Disorder, Major / drug therapy
  • Depressive Disorder, Major / genetics*
  • Depressive Disorder, Major / psychology
  • Female
  • Genetic Association Studies
  • Humans
  • Male
  • Norepinephrine Plasma Membrane Transport Proteins / genetics
  • Selective Serotonin Reuptake Inhibitors / therapeutic use*
  • Serotonin Plasma Membrane Transport Proteins / genetics
  • Suicidal Ideation
  • Suicide*
  • Tumor Necrosis Factor-alpha / genetics

Substances

  • Antidepressive Agents, Tricyclic
  • Brain-Derived Neurotrophic Factor
  • CREB1 protein, human
  • Cyclic AMP Response Element-Binding Protein
  • Norepinephrine Plasma Membrane Transport Proteins
  • SLC6A2 protein, human
  • SLC6A4 protein, human
  • Serotonin Plasma Membrane Transport Proteins
  • Serotonin Uptake Inhibitors
  • TNF protein, human
  • Tumor Necrosis Factor-alpha
  • BDNF protein, human