There is also no clear consensus regarding the best treatment among the greater mental health professional community which included clinical psychologists, social workers, licensed therapists MFTs) and psychiatrists. Although most trauma neuroscientifically informed practitioners understand the importance of utilizing a combination of both top down and bottom up interventions as well as including somatic interventions (sensorimotor psychotherapy or somatic experiencing or yoga) for the purposes of processing and integrating trauma memories. Survivors with complex trauma often struggle to find a mental health professional who is properly trained in trauma informed practices. They can also be challenging to receive adequate treatment and services to treat a mental health condition which is not universally recognized or well understood by general practitioners. Allistair and Hull echo the sentiment of many other trauma neuroscience researchers (including Bessel van der Kolk and Bruce D. Perry) who argue: 

Complex presentations are often excluded from studies because they do not fit neatly into the simple nosological categorisations required for research power. This means that the most severe disorders are not studied adequately and patients most affected by early trauma are often not recognised by services. Both historically and currently, at the individual as well as the societal level, "dissociation from the acknowledgement of the severe impact of childhood abuse on the developing brain leads to inadequate provision of services. Assimilation into treatment models of the emerging affective neuroscience of adverse experience could help to redress the balance by shifting the focus from top-down regulation to bottom-up, body-based processing."
Some of these additional interventions and modalities include:

biofeedback
dyadic resourcing (used with EMDR)
emotionally focused therapy
emotional freedom technique (EFT) or tapping
equine-assisted therapy
expressive arts therapy
internal family systems therapy
dialectical behavior therapy (DBT)
family systems therapy
group therapy
neurofeedback
psychodynamic therapy
sensorimotor psychotherapy
somatic experiencing
yoga, specifically trauma-sensitive yoga

Arguments against diagnosis
Though acceptance of the idea of complex PTSD has increased with mental health professionals, the fundamental research required for the proper validation of a new disorder is insufficient as of 2013. The disorder was proposed under the name DES-NOS (Disorder of Extreme Stress Not Otherwise Specified) for inclusion in the DSM-IV but was rejected by members of the Diagnostic and Statistical Manual of Mental Disorders (DSM) committee of the American Psychiatric Association for lack of sufficient diagnostic validity research. Chief among the stated limitations was a study which showed that 95% of individuals who could be diagnosed with the proposed DES-NOS were also diagnosable with PTSD, raising questions about the added usefulness of an additional disorder.Following the failure of DES-NOS to gain formal recognition in the DSM-IV, the concept was re-packaged for children and adolescents and given a new name, developmental trauma disorder. Supporters of DTD appealed to the developers of the DSM-5 to recognize DTD as a new disorder. Just as the developers of DSM-IV refused to included DES-NOS, the developers of DSM-5 refused to include DTD due to a perceived lack of sufficient research.