The widely used
DSM and
ICD manuals are generally limited to categorical diagnoses. However, some categories include a range of subtypes which vary from the main diagnosis in clinical presentation or typical severity. Some categories could be considered
subsyndromal (not meeting criteria for the full diagnosis) subtypes. In addition, many of the categories include a '
not otherwise specified' subtype, where enough symptoms are present but not in the main recognized pattern; in some categories this is the most common diagnosis. The DSM-5 only formally recognises the "autism spectrum" and the "schizophrenia spectrum", but many other spectrum concepts have been proposed in research, and are sometimes used in clinical practice, including the following. A
generalized anxiety spectrum – this spectrum has been defined by duration of symptoms: a type lasting over six months (a DSM-IV criterion), over one month (DSM-III), or lasting two weeks or less (though may recur), and also isolated anxiety symptoms not meeting criteria for any type. A
social anxiety spectrum – this has been defined to span
shyness to
social anxiety disorder, including typical and atypical presentations, isolated signs and symptoms, and elements of
avoidant personality disorder. A
panic-
agoraphobia spectrum – due to the
heterogeneity (diversity) found in individual clinical presentations of panic disorder and agoraphobia, attempts have been made to identify symptom clusters in addition to those included in the DSM diagnoses, including through the development of a dimensional questionnaire measure. A
post-traumatic stress spectrum or
trauma and
loss spectrum – work in this area has sought to go beyond the DSM category and consider in more detail a spectrum of severity of symptoms (rather than just presence or absence for diagnostic purposes), as well as a spectrum in terms of the nature of the stressor (e.g. the traumatic incident) and a spectrum of how people respond to trauma. This identifies a significant amount of symptoms and impairment below threshold for DSM diagnosis but nevertheless important, and potentially also present in other disorders a person might be diagnosed with. A
depersonalization-
derealization spectrum – although the DSM identifies only a chronic and severe form of
depersonalization derealization disorder, and the ICD a 'depersonalization-derealization syndrome', a spectrum of severity has long been identified, including short-lasting episodes commonly experienced in the general population and often associated with other disorders.
Obsessions and compulsions An
obsessive–compulsive spectrum – this can include a wide range of disorders from
Tourette syndrome to the
hypochondrias, as well as forms of
eating disorder, itself a spectrum of related conditions.
General developmental disorders An autistic spectrum – in its simplest form this joins
autism and
Asperger syndrome, and can additionally include other
pervasive developmental disorders (PDD). These include
PDD 'not otherwise specified' (including 'atypical autism'), as well as
Rett syndrome and
childhood disintegrative disorder (CDD). The first three of these disorders are commonly called the autism spectrum disorders; the last two disorders are much rarer, and are sometimes placed in the autism spectrum and sometimes not. The merging of these disorders is based on findings that the symptom profiles are similar, such that individuals are better differentiated by clinical specifiers (i.e. dimensions of severity, such as extent of social communication difficulties or how fixed or restricted behaviors or interests are) and associated features (e.g. known genetic disorders, epilepsy, intellectual disabilities). In the
DSM-5, the autism spectrum disorders were unified into a single
autism spectrum disorder (ASD). The term
specific developmental disorders is reserved for categorizing particular specific
learning disabilities and developmental disorders affecting coordination.
Schizophrenia spectrum The
schizophrenia spectrum or
psychotic spectrum – there are numerous
psychotic spectrum disorders already in the DSM, many involving reality distortion. These include: • Five subtypes of schizophrenia (although eliminated in DSM-5) • Two forms of shorter duration (
schizophreniform disorder and
brief psychotic disorder) • three delusional disorders (persistent
delusional disorder,
shared psychotic disorder,
other delusional disorders) •
Schizoaffective disorder: symptoms of schizophrenia and a
mood disorder (
depression or
bipolar disorder) •
Catatonia •
Schizotypal personality disorder •
Other and unspecified non-organic psychotic disorders (Atypical psychosis), (inc: chronic hallucinatory psychosis)
Predisposition to schizophrenia is classified with the neologism
schizotaxia. There are also traits identified in first degree relatives of those diagnosed with schizophrenia associated with the spectrum. Other spectrum approaches include more specific individual phenomena which may also occur in non-clinical forms in the general population, such as some paranoid beliefs or hearing voices. Psychosis accompanied by mood disorder may be included as a schizophrenia spectrum disorder, or may be classed separately as below. Schizophrenia spectrum disorders do not necessarily involve psychotic symptoms.
Schizoid personality disorder,
schizotypal personality disorder, and
paranoid personality disorder can be considered 'schizophrenia-like personality disorders' because of their similarities to the schizophrenia spectrum. Some researchers have also proposed that avoidant personality disorder and related
social anxiety traits should be considered part of a schizophrenia spectrum. Some sources divide the schizophrenia spectrum into psychotic and non-psychotic disorders, with schizotypal personality disorder included among the non-psychotic disorders (and sometimes schizoid personality disorder as well). The "schizophrenia spectrum" section in the DSM-5 deals with psychotic disorders only, and hence excludes schizotypal personality disorder, while the "schizophrenia spectrum" block in the ICD-11 includes schizotypal personality disorder as well. From a
psychodynamic or
psychoanalytic perspective, the distinction between schizoid, schizotypal and avoidant personality disorders is sometimes considered inconsequential, as these disorders are understood to share similar experiential characteristics and be differentiated chiefly by surface-level observations about behavioral differences. Psychotic disorders such as schizophrenia and schizoaffective disorders are then thought to be the psychotic expression of a shared underlying personality structure. – this spectrum refers to features of both
psychosis (
hallucinations,
delusions,
thought disorder etc.) and
mood disorder (see below). The DSM has, on the one hand, a category of schizoaffective disorder (which may be more
affective (mood) or more schizophrenic), and on the other hand psychotic bipolar disorder and
psychotic depression categories. A spectrum approach joins these together and may additionally include specific clinical variables and outcomes, which initial research suggested may not be particularly well captured by the different diagnostic categories except at the extremes.
Mood A
mood disorder (
affective) spectrum or bipolar spectrum These approaches have expanded out in different directions. On the one hand, work on
major depressive disorder has identified a spectrum of subcategories and sub-threshold symptoms that are prevalent, recurrent and associated with treatment needs. People are found to move between the subtypes and the main diagnostic type over time, suggesting a spectrum. This spectrum can include already recognised categories of
minor depressive disorder, '
melancholic depression' and various kinds of
atypical depression. In another direction, numerous links and overlaps have been found between major depressive disorder and bipolar syndromes, including
mixed states (simultaneous depression and
mania or
hypomania). Hypomanic ('below manic') and more rarely manic signs and symptoms have been found in a significant number of cases of major depressive disorder, suggesting not a categorical distinction but a dimension of frequency that is higher in bipolar II and higher again in bipolar I. In addition, numerous subtypes of bipolar have been proposed beyond the types already in the DSM (which includes a milder form called
cyclothymia). These extra subgroups have been defined in terms of more detailed gradations of mood severity, or the rapidity of cycling, or the extent or nature of psychotic symptoms. Furthermore, due to shared characteristics between some types of bipolar disorder and
borderline personality disorder, some researchers have suggested they may both lie on a spectrum of affective disorders, although others see more links to post-trauma syndromes.
Substance use A spectrum of
drug use,
drug abuse and
substance dependence – one spectrum of this type, adopted by the Health Officers Council of
British Columbia in 2005, does not employ loaded terms and distinctions such as "use" versus "abuse", but explicitly recognizes a spectrum ranging from potentially beneficial to
chronic dependence. The model includes the role not just of the individual but of society, culture and availability of substances. In concert with the identified spectrum of drug use, a spectrum of policy approaches was identified which depended partly on whether the drug in question was available in a legal, for-profit commercial economy, or at the other of the spectrum only in a criminal/prohibition, black-market economy. In addition, a standardized questionnaire has been developed in psychiatry based on a spectrum concept of substance use.
Paraphilias and obsessions The interpretative key of "spectrum," developed from the concept of "related disorders," has been considered also in
paraphilias. Paraphilic behavior is triggered by thoughts or urges that are psychopathologically close to obsessive impulsive area. Hollander (1996) includes in the obsessive-compulsive spectrum neurological obsessive disorders, body-perception-related disorders and impulsivity-compulsivity disorders. In this continuum from impulsivity to compulsivity it is particularly hard to find a clear borderline between the two entities. On this point of view, paraphilias represent such as sexual behaviors due to a high impulsivity-compulsivity drive. It is difficult to distinguish impulsivity from compulsivity: Sometimes paraphilic behaviors are prone to achieve pleasure (desire or fantasy); in some other cases, these attitudes are merely expressions of anxiety, and the atypical behavior is an attempt to reduce anxiety. In the last case, the pleasure gained is short in time and is followed by a new increase in anxiety levels, such as it can be seen in an obsessive patient after he performs his compulsion.
Disruptive behavior disorders The
disruptive behavior disorders – commonly defined as including
oppositional defiant disorder and
conduct disorder, with ADHD
Fetal alcohol spectrum disorders Fetal alcohol spectrum disorders have both physical signs (such as facial malformations) but also psychological signs and symptoms, including behavior problems similar to
ADHD,
learning and
speech problems, and
intellectual disability. ==Broad spectrum approach==