This editorial introduces a special issue of BJPsych Advances on neuroscience in 21st-century psychiatry. It focuses on two articles in particular, which reveal the contributions of neuroscience to fully integrated biopsychosocial models of human experience.

Comorbid anxiety symptoms are common in depression, and adding benzodiazepines to antidepressant treatment may seem a rational clinical solution. Benzodiazepines also have potential to reduce the initial anxiety that may be caused by early antidepressant treatment (owing to their inhibitory effect via GABAA receptor binding). This month's Cochrane Corner review examines the evidence behind combination treatment versus antidepressants alone in major depressive disorder, in terms of both the clinical and neuroscientific context. The review provides evidence that, in the first 4 weeks of treatment, additional medication with a benzodiazepine may lead to greater improvements than antidepressant alone on ratings of severity, response rates and remission rates for depression, but not on measures of anxiety.

Patients with psychiatric illness present a unique challenge to clinicians: in contrast to the traditional medical model, in which patients are conceptualised as being stricken by a disease, patients with certain psychiatric illnesses may seem complicit in the illness. Questions of free will, choice and the role of the physician can cause clinicians to feel helpless, disinterested or even resentful. These tensions are a lasting legacy of centuries of mind–body dualism. Over the past several decades, modern tools have finally allowed us to break down this false dichotomy. Integrating a modern neuroscience perspective into practice allows clinicians to conceptualise individuals with psychiatric illness in a way that promotes empathy and enhances patient care. Specifically, a strong grasp of neuroscience prevents clinicians from falling into the trap in which behavioural aspects of a patient's presentation are perceived as being separate from the disease process. We demonstrate the value of incorporating neuroscience into a biopsychosocial formulation through the example of a ‘difficult patient’.

Psychiatry intertwines mind and brain, sometimes in a strained marriage. Psychiatrists feel the criticism of a ‘narrow’ biological or medical (and medication) focus, and we are very aware of the limitations of all treatments and diagnostic systems. Many understandably move towards a more social approach, seeing individuals in their wider lives. But there are dangers in losing the brain, something unique to our specialty in the world of mental health. This reflective piece calls for us to rediscover the joy of the science of the brain, which augments, not conflicts with, psychosocial approaches.

Historically, Parkinson's disease was viewed as a motor disorder and it is only in recent years that the spectrum of non-motor disorders associated with the condition has been fully recognised. There is a broad scope of neuropsychiatric manifestations, including depression, anxiety, apathy, psychosis and cognitive impairment. Patients are more predisposed to delirium, and Parkinson's disease treatments give rise to specific syndromes, including impulse control disorders, dopamine agonist withdrawal syndrome and dopamine dysregulation syndrome. This article gives a broad overview of the spectrum of these conditions, describes the association with severity of Parkinson's disease and the degree to which dopaminergic degeneration and/or treatment influence symptoms. We highlight useful assessment scales that inform diagnosis and current treatment strategies to ameliorate these troublesome symptoms, which frequently negatively affect quality of life.

Jones et al's review of the assessment and management of the neuropsychiatric manifestations of Parkinson's disease serves as a practical guide to clinicians. This commentary outlines some of the underlying neuroscience and psychological sequelae of this range of conditions, offering a takeaway message to the clinician with an interest in Parkinson's neuropsychiatry.

There is considerable work being carried out in neuroscientific laboratories to delineate the mechanisms underlying single-gene disorders, particularly those related to intellectual disability and autism spectrum disorder. Many clinicians will have little if any direct experience of this type of work and so find the procedures and terminology difficult to understand. This article describes some of the laboratory techniques used and their increasing relevance to clinical practice. It is pitched for clinicians with little or no laboratory science background.

We consider some advances in relational and affective neuroscience and related disciplines that attempt to resolve some fundamental aspects of the mind–brain problem. We consider the key role of affect in generating consciousness and in meeting our essential survival needs; the neural correlates of relating; how self and other are represented in the brain and awareness of self and other is generated through interoceptive predictive processes. We describe some leading models of the generation and purpose of consciousness, linking theories of affective and cognitive consciousness. We discuss psychiatric and psychotherapeutic innovations arising from this research, new integrated biopsychosocial interventions and the obstacles to be overcome in applying these models in practice.

Addiction is a global health problem with a chronic relapsing nature for which there are few treatment options. In the past few decades, neuroimaging has allowed us to better understand the neurobiology of addiction. Functional neuroimaging paradigms have been developed to probe the neural circuits underlying addiction, including reward, inhibitory control, stress, emotional processing and learning/memory networks. Functional neuroimaging has also been used to provide biological support for the benefits of psychosocial and pharmacological interventions, although evidence remains limited and often inconclusive in this area, which may contribute to the variability in treatment efficacy. In this article, we discuss the changing definitions and clinical criteria that describe and classify addictive disorders. Using examples from functional neuroimaging studies we summarise the neurobiological mechanisms that underpin drug use, dependence, tolerance, withdrawal and relapse. We discuss the links between functional neuroimaging and treatment, outline clinical management in the UK and give an overview of future directions in research and addiction services.

Training in neuroscience is vital to the future of psychiatry as a medical specialty. Trainees and trainers alike demonstrate a desire to keep up to date with developments in the associated scientific fields. Neuroscience increasingly underpins clinical assessments, treatment options and patients’ expectations. Psychiatry training in the UK can embrace neuroscience at many levels, from discussing patient presentations with supervisors, to teaching programmes supported by the Royal College of Psychiatrists’ activities. Although challenges remain, neuroscience literacy enhances the specialty and will improve patient care.