An introduction to DSM-5

In this short article the author attempts a skeletal summary of the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5), published by the American Psychiatric Association (APA) in 2013. 

DSM-5 classification

Neurodevelopmental disorders

Neurodevelopmental disorders are of early onset, often before starting pre-school. Developmental deficits cause impairments of personal, social, academic or occupational function. Many patients formerly labelled with Asperger syndrome would now be diagnosed as having autism spectrum disorders “without language or intellectual impairment’’. Intellectual disability (‘‘intellectual developmental disorder’’ in ICD-11) can be mild, moderate or severe; “global developmental delay” is used when the patient is less than five years old and clinical severity cannot be assessed. “Unspecified intellectual disability” is used for people over five years of age and clinical severity cannot be assessed. Communication disorders are language problems (such as poor word knowledge or use, poor sentence construction, difficulty explaining and conversing), speech sound difficulties (interfere with intelligibility and prevent good verbal communication), stuttering (childhood-onset fluency disorder) and social (pragmatic) communication.  Autism spectrum disorders involve deficits in social-emotional reciprocity, non-verbal communication, and developing, maintaining and understanding relationships; stereotyped/repetitive motor movements or use of objects or speech, insistence on sameness, highly restricted or fixed interests (abnormal in intensity and focus) and excessive over- and under-reactions to sensory input or unusual interest in sensory aspects of the environment. Attention-deficit/hyperactivity disorder (ADHD) and specific learning disorder (reading, writing, maths) appear basically unchanged. Motor disorders include developmental co-ordination disorder (clumsy child syndrome), stereotypic movement disorder (+/- self-injury) and tic disorders (Tourette, persistent/chronic motor or vocal).

Bipolar and related disorders

Bipolar (BP) and related conditions include BP I disorder, BP II disorder (hypomania is less impairing than mania and does not lead to hospitalisation), cyclothymic disorder, substance/medication-induced BP disorder and cases due to another medical disorder. Depressive disorders include disruptive mood dysregulation disorder, major depressive disorder (with/without psychotic features; single episode/recurrent; specify if with anxious distress, mixed features, melancholic features, atypical features, mood-congruent or mood-incongruent psychotic features, catatonia, peripartum onset, or seasonal pattern, the last applying only to recurrent episode), persistent depressive disorder (dysthymia), premenstrual dysphoric disorder, substance/medication-induced depressive disorder and depressive disorder due to another medical disorder. 

Anxiety disorders

Include separation anxiety disorder, selective mutism, specific phobia (animal, blood-injection/other medical care, situational and “other”), panic disorder, panic attack, agoraphobia, generalised anxiety disorder, substance/medication-induced anxiety disorder, and anxiety disorder due to another medical condition.

OCD and related disorders

Obsessive-compulsive disorder (OCD) and related disorders include OCD itself, body dysmorphic disorder (with/without muscle dysmorphia), hoarding disorder (with/without excessive acquisition of items that are not needed or cannot be stored – state level of insight and presence/absence of delusions), trichotillomania (hair-pulling disorder), excoriation (skin-picking) disorder (leads to skin lesions and patient tries to stop the behaviour), OCD and related disorders due to substance/medication or another medical condition. An “other specified”  group includes body dysmorphic-like disorder (BDLD) with actual flaws (more than slight flaws but excessive preoccupation), BDLD without repetitive behaviours, body-focused repetitive behaviour disorder (eg. nail or lip biting, cheek chewing – patient tries to stop these actions), obsessional jealousy (non-delusional preoccupation with partner’s perceived infidelity that may be accompanied by repetitive behaviours and mental acts), shubo-kyofu (variant of taijin kyofusho – excessive fears of having a bodily deformity), koro (sudden fear that penis or vulva or nipples will recede into the body with or without a fatal outcome) and jikoshu-kyofu (olfactory reference syndrome: another variant of taijin kyofusho – fear of having offensive body odour).

Trauma and stressor-related disorders

Trauma and stressor-related disorders include reactive attachment disorder (child avoids comfort seeking and shows inadequate response to being comforted – seen in neglected children), disinhibited social engagement disorder (a neglected child is over familiar with unfamiliar adults), PTSD (specify if dissociation is present or there is a delay in onset – latter if full criteria not met for at least six months after event), acute stress disorder and adjustment disorders (anxiety, mixed anxiety-depression, conduct, mixtures of all foregoing).

Dissociative disorders

Dissociative disorders include dissociative identity disorder (described as a possession experience in some cultures), dissociative amnesia (with or without fugue), and depersonalisation/derealisation disorder.

Somatic symptom and related disorders

Somatic symptom and related disorders include somatic symptom disorder (with or without pain, persistence), illness anxiety disorder, conversion disorder (weakness or paralysis, abnormal movement, swallowing problems, speech symptoms, attacks/seizures, anaesthesia/sensory loss, special senses, mixed), psychological factors affecting other medical conditions and factitious disorder (imposed on self or others).

Feeding and eating disorders

Feeding and eating disorders include pica (in a child or an adult), rumination disorder, avoidant/restrictive food intake disorder (replaces feeding disorder of infancy/early childhood), anorexia nervosa (restricting or binge-eating/purging; BMI used to grade severity), bulimia nervosa (severity graded by weekly number of inappropriate compensatory behaviours), binge-eating disorder (patient binges at least weekly for three months and does not use inappropriate compensatory behaviours) and other specified feeding and eating disorders (includes purging disorder [patient wants to influence shape or weight but does not binge] and night eating syndrome [eats excessively at night after waking or shortly before retiring]).

Sleep-wake disorders

Sleep-wake disorders include insomnia, hypersomnolence, narcolepsy (include information on cataplexy, hypocretin status and other stated features), breathing-related sleep disorders  such as obstructive sleep apnoea/hypopnoea, central sleep apnoea (CSA), Cheyne-Stokes breathing, CSA with opioid abuse, sleep-related hypoventilation, idiopathic hypoventilation, congenital central alveolar hypoventilation, comorbid sleep-related hypoventilation, circadian rhythm sleep-wake disorders (delayed or advanced phase, irregular and non-24-hour types) and shift work. Parasomnias include non-REM sleep arousal disorders, sleepwalking (with/without eating, sexual activity [sexsomnia]), sleep terror, nightmare, REM sleep behaviour disorder, restless legs and substance/medication-induced. 

Sexual dysfunctions

Sexual dysfunctions include delayed ejaculation, erectile disorder, female orgasmic disorder, female sexual interest/arousal disorder, genito-pelvic pain/penetration disorder (combines vaginismus with dyspareunia), male hypoactive sexual desire disorder, premature/early ejaculation and substance/medication-induced sexual dysfunction. Gender dysphoria replaces gender identity disorder and focuses on dysphoria as the clinical problem rather than the identity as such; gender dysphoria refers to distress accompanying incongruity between experienced or expressed gender and assigned gender; one is asked to state the age group of the patient.

Disruptive disorders

Disruptive, impulse-control, and conduct disorders include oppositional defiant disorder (angry, irritable, touchy, easily annoyed, argumentative, vindictive; severity rated according to number of settings in which behaviour is manifested), intermittent explosive disorder (must be at least six years old), conduct disorder (state if onset in childhood or adolescence), antisocial personality disorder, pyromania and kleptomania. This group of disorders manifests in behaviours that violate the rights of others and/or bring the individual into significant conflict with societal norms or authority figures. Different component disorders affect emotional and behavioural regulation differently. Many defining symptoms can occur in typically developing individuals so one must know what is normative.

Substance-related disorders

Substance-related and addictive disorders include substance use and substance-induced disorders: alcohol, caffeine, cannabis, phencyclidine, other hallucinogen, hallucinogen persisting perception disorder, inhalant, opioid, sedative/hypnotic/anxiolytic, stimulant, tobacco and other substances (specify intoxication, withdrawal). Pathological gambling is included here. Internet gaming and sex/exercise/shopping addiction are not included but not enough is known about them.

Neurocognitive disorders

Neurocognitive disorders include dementia and amnestic disorder. Objective tests should be interpreted carefully, eg. a poor result may reflect the normal state of the patient. Delirium (state known cause/s, duration, hyperactive or hypoactive or mixed) and major and mild neurocognitive disorders (Alzheimer’s, frontotemporal, Lewy body, vascular, trauma, HIV, prion, Parkinson’s disease, Huntington’s disease, other/multiple causes) are found in this chapter. Mild cases were subsumed under “cognitive disorders not otherwise specified” in DSM-IV. In mild cases patients are able to manage their affairs, although with greater effort; compensatory strategies or accommodation may be required. One must outrule delirium and depression. Boundaries between normal and poor neurocognitive functioning are inherently arbitrary. Both history and objective assessment are required.

Other mental disorders

Other mental disorders include those due to a specified or unspecified medical condition. Medication-induced movement disorders and other adverse effects of medication include, for example, postural tremor, tardive dyskinesia and antidepressant discontinuation syndrome. Other conditions that may be a focus of clinical attention are not mental disorders but are included to draw attention to them – they cover family issues, primary support group, abuse/neglect, spouse/partner issues, education/occupation, housing and economic, social environment (includes stigma), crime/legal system and other (including non-adherence, availability of services, overweight/obesity, malingering and borderline intellectual functioning).

Cultural formulation involves a systematic assessment of cultural identity (patient’s reference groups), a cultural conceptualisation of distress (eg. explanatory models), psychosocial stressors and cultural features of vulnerability/resilience (environment, religion, supports, etc), cultural features of relationship between individual and clinician (such as language, experience of racism, etc) and a synthesis of the foregoing under “overall cultural assessment”. The Cultural Formulation Interview includes 16 questions covering items such as values, current social context and influence of others.

Personality disorders

The alternative DSM-5 model for personality disorders focuses on impaired personality functioning (disturbed self and interpersonal functioning) and abnormal personality traits (five broad trait domains containing 25 specific trait facets). It can be used to derive antisocial, avoidant, borderline, narcissistic, obsessive-compulsive and schizotypal personality disorders. It can also diagnose what amounts to non-specified (mixed) personality disorder. The model also looks at pervasiveness/stability and differential diagnosis.

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Discussion

Intellectual disability replaces mental retardation in the US because of the US law (Public Law 111-256, “Rosa’s Law”) that bans use of the older term. Severity depends on adaptive functioning and required supports. Very low IQs are relatively invalid. Test scores may be affected by practice and by the Flynn effect (overly high scores because norms are out of date). Clinical judgement is required to interpret IQ test results. Language disorder is evident in speech, writing or sign language. A person must understand and express language. In speech sound disorder the child continues to use simplified forms of words when the average peer can use clear words. In social (pragmatic) communication disorder deficits occur in social communication, changing communication to suit context or needs of the listener, problems following rules for conversation or telling a story and problems understanding what is explicitly said (such as making inferences) and non-literal/ambiguous language (eg. humour, idioms, etc).

In the clumsy child syndrome co-ordination skills lag behind age and opportunities to acquire and practise skills. Motor skills are performed slowly and inaccurately.  Gross or fine (eg. writing) motor skill impairments may predominate. It is difficult to diagnose for certain before the age of five years because some children catch up and other causes of motor delay may not have fully manifested themselves.

In stereotypic movement disorder there are repetitive, apparently driven and seemingly meaningless movements, eg. hand flapping, body rocking, head banging, self-biting or hitting. It may be primary or secondary, eg. Lesch-Nyhan syndrome, Rett syndrome, fragile X syndrome, Cornelia de Lange syndrome and Smith-Magenis syndrome. Patients with tics may copy sounds or gestures of other people. These actions can be mistaken for bad manners.

In delusional disorder at least one month of delusions is required. If hallucinations are reported they are not prominent and they are related to the theme of a delusion. Patients may have “factual” insight, which is not true insight – they can tell the clinician how others view their beliefs as irrational but they still cling to such ideas themselves. Brief psychotic disorder lasts more than a day and less than a month. Postpartum onset is defined as “onset during pregnancy or within four weeks postpartum”! Schizophreniform disorder resembles schizophrenia but duration is less than six months and there is no requirement for functional decline. Mood symptoms in schizophrenia should, in total, last for only a “minority” of the duration of the active or residual phases of the illness.

Regarding schizoaffective disorder, a mood episode and active-phase schizophrenia symptoms co-occur and are preceded or followed by at least two weeks of delusions or hallucinations in the absence of prominent mood symptoms. DSM-5 is sceptical about the status of this disorder. Do not use loss of interest or pleasure in making the diagnosis of schizoaffective disorder because they are common in schizophrenia but rely instead on pervasive depressed mood.  Very short duration of mood symptoms does not detract from a diagnosis of schizophrenia. In making the diagnosis of schizoaffective disorder you should look at the entire history of the illness (DSM-IV required one only to look at the current period of illness).

Separation of bipolar disorders from depressive disorders reflects the idea that they lie clinically and aetiologically between schizophrenia spectrum and depressive disorders. Full persistence of manic or hypomanic symptoms while a person is receiving treatment is now accepted as part of BP I and II disorders, respectively. If the patient realises that a drug has caused hallucinations the diagnosis is substance intoxication or withdrawal with perceptual disturbance.

Separation anxiety disorder is often comorbid with various anxiety disorders, PTSD, OCD, personality disorder as well as depressive and bipolar affective disorders.

In somatic symptom disorder one or more somatic symptoms that are distressing or disrupt daily life to a significant degree are present. Record “persistent” if it lasts more than six months. Severity is graded by number of symptoms. There may or may not be an accompanying medical condition. Worry levels are high. There is high use of medical care but with little alleviation of concerns. Such patients may demean the medical care that they receive.