2 Clinical need and practice
2.1 Mental disorders such as depression and anxiety are characterised by a number of symptoms. Diagnosis is made using the International Statistical Classification of Diseases and Related Health Problems − 10th Revision (ICD-10) or the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) (World Health Organization 1992 and American Psychiatric Association 1994, respectively).
2.2 Depression refers to a wide range of mental health problems characterised by the absence of positive affect (a loss of interest and enjoyment in ordinary things and experiences), low mood and a range of associated emotional, cognitive, physical and behavioural symptoms. Depression varies in severity, and individuals with major depression can be differentiated into those with mild, moderate and severe disease on the basis of symptom severity and impairment of functioning.
2.3 There are several anxiety disorders including generalised anxiety disorder (GAD), panic disorder, phobias (agoraphobia without panic disorder, agoraphobia with panic disorder, social phobias and specific [isolated] phobias) and OCD. Symptoms of depression and anxiety more often than not co-exist. There is also often overlap between panic and phobias, with many people having both.
2.4 OCD is clinically distinct from the other anxiety disorders. Obsessions are defined as being recurrent persistent thoughts, impulses or images that are intrusive and inappropriate and that cause marked anxiety or distress. Compulsions are repetitive, purposeful and ritualistic behaviours or mental acts, performed in response to obsessional intrusion, to a set of rigidly prescribed rules.
2.5 Depression and anxiety have a broad impact and are associated with poor quality of life, occupational disadvantage, impairment in interpersonal and family relationships, and suicide. Diagnosable depressive disorders are implicated in 40–60% of suicide attempts, with 10–15% of people with major depressive disorders eventually committing suicide. ICD-10 uses an agreed list of ten depressive symptoms and divides the common form of major depressive episode into four groups: not depressed, mildly depressed, moderately depressed and severely depressed.
2.6 In 2000, the Psychiatric Morbidity Survey conducted by the Office of Population Censuses and Surveys found prevalences, per 1000 people aged 16–74 years in England and Wales, of 187 for mixed anxiety and depression, 95 for GAD and 62 for depressive episode. Corresponding figures for phobia, panic disorder and OCD were 38, 13 and 38, respectively. In 1995, 9 in every 100 people with mental health problems who consulted their GP were referred to specialist services for assessment, advice and treatment.
2.7 There is wide variation in the recorded prevalence and incidence of anxiety and depression. However, many individuals do not seek treatment, and both anxiety and depression are often undiagnosed. Recognition of anxiety disorders by GPs is often poor, and only a small minority of people who experience anxiety disorders actually undergo treatment.
2.8 Anxiety and depression are currently managed by drug therapy or a range of 'psychotherapies' (a generic term to cover the predominantly talk-based psychological therapies in their various forms), or both. There is, however, wide variation in care practices among individual GPs. In addition to prescribed medication, support can include access to self-help material, exercise and referral for occupational therapy, vocational rehabilitation and counselling. Primary care counselling services are now being established in many primary care trusts (PCTs) in England. After an appropriate assessment, the counsellor can offer short-term therapeutic interventions for people with mild and moderate anxiety or depression or refer individuals with severe depression and anxiety to more specialised services. In 'stepped-care' approaches, the individual is given basic interventions at the start of therapy and is stepped up to more complex interventions as and when necessary. Although careful risk assessment is required, such approaches can theoretically minimise the need for more specialised services.
2.9 A broad range of psychotherapies is provided by a number of different health professionals in the NHS. The range includes CBT, behaviour therapy, interpersonal therapy, problem-solving therapy, non-directive counselling and short-term psychodynamic psychotherapy.
2.10 CBT is a generic term that refers to the pragmatic combination of concepts and techniques from cognitive therapy and behavioural therapy. Both of these use structured approaches based on the assumption that prior learning is currently having maladaptive consequences. The purpose of therapy is to reduce distress or unwanted behaviour by undoing this learning or by providing new, more adaptive learning experiences. The way in which CBT is delivered varies, depending on the individual's needs.
2.11 The effectiveness of CBT is supported by evidence from randomised controlled trials (RCTs). For many diagnostic groups, controlled trials indicate that approximately 50% of individuals with depression experience clinically important improvement, which is similar to outcomes achieved with antidepressant drugs.
2.12 The behavioural component of CBT aims to reduce dysfunctional emotions and behaviour by altering the individual's behaviour and the factors that control it. Methods used may involve behavioural experiments to test irrational thoughts, graded exposure to feared situations, target setting and activity scheduling. The cognitive component attempts to reduce dysfunctional emotions and behaviour by altering individual appraisals and thinking patterns. Methods used include discussion of the cognitive model, diary keeping (developing awareness of thoughts, affect, behaviour and physical symptoms), examination of evidence for and against dysfunctional beliefs, cognitive rehearsal and the development of skills to challenge negative thoughts and dysfunctional assumptions.
2.13 Anxiety disorders are commonly treated by the CBT technique of 'self-exposure' in which individuals expose themselves to situations of increasing difficulty. Individuals are asked to record their thoughts and beliefs about the exposure situation before, during and after exposure. Behavioural treatment for OCD involves exposure to whatever evokes obsessions and prevents avoidance or neutralisation of the resulting anxiety. Cognitive methods aim to challenge the obsessive thoughts.
2.14 In comparison with other psychotherapies, CBT is brief, highly structured, problem-orientated and prescriptive, and individuals are active collaborators. The optimal length of therapy will vary among individuals. For mild and moderate depression, brief CBT of six to eight sessions over 10 to 12 weeks is usual. For moderate to severe depression, the duration is typically in the range of 16 to 20 sessions over 6 to 9 months. For anxiety the optimal range of duration of CBT is between 7 and 14 hours. For people with OCD in whom the degree of functional impairment is mild, up to 10 hours of CBT including exposure and response prevention (ERP) may be offered; for those with a higher degree of functional impairment more than 10 hours of CBT that includes ERP should be offered. CBT-trained therapists can be from a number of disciplines and may include clinical psychologists, mental health nurse specialists and psychiatrists.
2.15 There is evidence that some people prefer 'talking therapies' involving face-to-face contact with the therapist rather than drug treatment. However, access to counselling and psychotherapy services is restricted by the high level of demand, the limited availability of therapists – especially in some geographical areas – and a lack of clear referral criteria and pathways.
2.16 Computerised CBT (CCBT) is included as an option in the stepped-care model presented in the NICE clinical guideline for the management of depression in primary and secondary care and in the NICE clinical guideline for the management of anxiety (panic disorder, with or without agoraphobia, and GAD) in adults in primary, secondary and community care. A guideline for OCD has been published (see Section 8 − Related guidance).
2.17 Within step 2 of the NICE clinical guideline for the management of depression in primary and secondary care, CCBT is included as a more structured treatment alternative (together with problem solving, brief CBT or counselling) to initial interventions such as exercise or guided self-help.