Classification Systems: DSM-5 and ICD-11

Two classification systems provide the dominant international frameworks for categorising mental health conditions. The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), published by the American Psychiatric Association (2013), is widely used in research and in private and clinical settings in the UK. The International Classification of Diseases, Eleventh Revision (ICD-11), published by the World Health Organization (2019), is the system used by the NHS for clinical coding and reporting.

Both systems group conditions into categories based on clusters of symptoms and their duration, severity, and impact on functioning. Counsellors do not use these systems to diagnose clients, but familiarity with how conditions are defined helps counsellors recognise presentations that may require additional professional support, communicate effectively with other professionals, and understand the language clients may use about themselves.

It is worth noting that both systems are periodically revised as understanding develops, and that classification is always an approximation of a complex lived reality. Many clients present with symptoms that cut across diagnostic categories, and a label does not tell a counsellor everything – or even most things – about a person.

Depression

Depression is one of the most common presentations in counselling. According to NHS data, depression affects around one in six people in England at some point in their lives. Core symptoms include persistent low mood, loss of interest or pleasure in activities (anhedonia), fatigue, changes in sleep or appetite, difficulty concentrating, feelings of worthlessness or excessive guilt, and in severe cases, thoughts of self-harm or suicide.

NICE guidelines (CG90, updated 2022) describe a stepped care approach to depression, with lower-intensity interventions such as guided self-help and psychological therapies recommended for mild to moderate presentations, and medication or specialist psychological therapies for more severe depression. Counselling is included within NICE’s recommended treatments for mild to moderate depression. For clients presenting with severe or recurrent depression, risk to self must always be assessed and appropriate referral considered.

Anxiety Disorders

Anxiety disorders form a group of related conditions characterised by excessive fear, worry, or avoidance that significantly impairs functioning. Common presentations include generalised anxiety disorder (pervasive, difficult-to-control worry across multiple domains), panic disorder (recurrent unexpected panic attacks with anticipatory anxiety about further attacks), social anxiety disorder (intense fear of social situations due to fear of negative evaluation), and specific phobias.

NICE guidelines recommend cognitive behavioural therapy (CBT) as a first-line psychological treatment for many anxiety disorders. Counsellors with a broader, humanistic or integrative training can still provide effective support, particularly where anxiety is rooted in relational or developmental factors, while being clear about the limits of their approach and the range of evidence-based options available.

Obsessive-Compulsive Disorder

Obsessive-compulsive disorder (OCD) is characterised by intrusive, unwanted thoughts (obsessions) and repetitive behaviours or mental acts performed to reduce the distress those thoughts cause (compulsions). OCD is often misunderstood by the public as meaning simply “liking things tidy,” when in reality it can be severely disabling. NICE guidance (CG31) recommends CBT with exposure and response prevention (ERP) as the primary treatment. Counsellors without specialist OCD training should refer clients with significant OCD presentations to appropriately trained practitioners rather than attempting to treat the condition within a general counselling model.

Bipolar Disorder

Bipolar disorder involves episodes of mania or hypomania (elevated or irritable mood, decreased need for sleep, inflated self-esteem, increased goal-directed activity, impulsive behaviour) alternating with episodes of depression. It affects approximately one to two percent of the population. Management typically involves mood-stabilising medication alongside psychological support. Counsellors working with clients who have a diagnosis of bipolar disorder should be aware that certain approaches – particularly those involving high levels of emotional intensity – may need to be adapted, and should work collaboratively with the client’s wider care team where one exists.

Personality Disorders

Personality disorders describe enduring patterns of inner experience and behaviour that deviate markedly from cultural expectations and cause significant distress or impairment. The ICD-11 moved away from categorising distinct personality disorder types toward a dimensional model that rates severity and specifies prominent trait domains (negative affectivity, detachment, dissociality, disinhibition, anankastia, borderline pattern). The previous categorical diagnoses, particularly emotionally unstable (borderline) personality disorder, remain in common clinical usage.

Working with clients who have personality disorder presentations can be rewarding but also requires particular attention to boundaries, therapeutic rupture and repair, and the counsellor’s own emotional responses. Specialist training – such as in mentalisation-based treatment or dialectical behaviour therapy – is recommended for counsellors wishing to work extensively in this area.

The Difference Between Counselling and Clinical Treatment

Counselling provides a relational, supportive, and exploratory space that is effective for a wide range of presentations. It is not, however, the same as clinical treatment, and counsellors must be clear about this distinction – with themselves and with clients. Some conditions require pharmacological management, specialist psychological therapies delivered by accredited therapists, or multidisciplinary care. Referral is not a failure; it is an act of professional responsibility.

Indicators for referral include: active psychosis or mania; significant risk to self or others; presentations suggesting complex PTSD or personality disorder requiring specialist intervention; a client whose physical health may be contributing to their presentation; and any situation where the counsellor feels out of their depth. The BACP Ethical Framework’s commitment to working within one’s competence applies directly here.

Mental Health Literacy and Safe Practice

Mental health literacy – the ability to recognise mental health conditions, understand their causes and treatments, and know where to seek help – supports counsellors in several ways: it enables accurate recognition of presentations that require urgent action; it facilitates respectful, informed conversations with clients about their experiences; and it helps counsellors work effectively alongside other professionals in the client’s wider network, such as GPs, community mental health teams, and social workers.