The boundary between mixed and manic episodes in the ICD-10 classification

Phenomenology of racing and crowded thoughts in mood disorders: a theoretical reappraisal

BACKGROUND

Racing thoughts is a frequent symptom in mood disorders, particularly mixed depressive states. This paper aims to summarize our current knowledge about its phenomenology and frequency in the spectrum of mood disorders, and to offer a new theoretical framework.

METHODS

We made a selective review of original and review papers in Medline and PsychInfo database using the keywords "racing thoughts", "crowded thoughts" and "depressive mixed state" in conjunction with "mood disorders".

RESULTS

In the context of a hypomanic state, "racing thoughts" may appear as a result from an excessive production of thoughts, moving quickly from one to the other, and generating a sense of fluidity and pleasantness. In the context of depression, "racing thoughts" are phenomenologically different and better described as "crowded thoughts": they are not only characterized by too many thoughts occurring at the same time in the field of consciousness, but perceived as unpleasant and induce the feeling that ideas are difficult to catch. DISCUSSION AND CLINICAL RELEVANCE: We suggest that crowded thoughts might result from the mixture of a hypomanic component, with an accelerated production of new thoughts (constituting the main source of this symptom in hypomania), and a depressive component, with a deficit of inhibition of previous thoughts (hence making thoughts crowded rather than truly racing). This distinction could help better identify crowded thoughts, and consequently depressive mixed states, which has important implications for therapeutic management. It might also help to further disentangle the psychobiological processes which contribute to the complexity of mood disorders.

The prevalence of mixed episodes during the course of illness in bipolar disorder

OBJECTIVE

To investigate the prevalence of mixed episodes during the course of illness in bipolar disorder.

METHOD

A total of 1620 patients with an ICD-10 diagnosis of bipolar affective disorder at the first psychiatric contact were identified in a period from 1994 to 2003 in Denmark and the prevalence of mixed, depressive and hypomanic/manic episodes were calculated at each episode.

RESULTS

The prevalence of mixed episodes increased from the first episode to the tenth episode, however, only for women (6.7% of the first episodes leading to psychiatric care compared with 18.2% of the tenth episodes). For men, the prevalence of mixed episodes was constantly low. At all episodes, the presence of a current mixed episode increased the risk substantially of getting a future mixed episode.

CONCLUSION

Clinicians should pay more attention to mixed episodes, especially among women, as they may represent an increasing treatment challenge as the illness progress.

Pure and mixed manic subtypes: a review of diagnostic classification and validation

OBJECTIVE

To review issues surrounding the diagnosis and validity of bipolar manic states.

METHODS

Studies of the manic syndrome and its diagnostic subtypes were reviewed emphasizing historical development, conceptualizations, formal diagnostic proposals, and validation.

RESULTS

Definitions delineating mixed and pure manic states derive some validity from external measures. DSM-IV and ICD-10 diagnosis of bipolar mixed states are too rigid and less restrictive definitions can be validated. Anxiety is a symptom often overlooked in diagnosis of manic subtypes and may be relevant to the mixed manic state. The boundary for separation of mixed mania and depression remains unclear. A 'pure' non-psychotic manic state similar to Kraepelin's 'hypomania' has been observed in several independent studies.

CONCLUSIONS

Issues surrounding diagnostic subtyping of manic states remain complex and the debates surrounding categorical versus dimensional approaches continue. To the extent that categorical approaches for mixed mania diagnosis are adopted, both DSM-IV and ICD-10 are too rigid. Inclusion of non-specific symptoms in definitions of mixed mania, such as psychomotor agitation, does not facilitate and may hinder the diagnostic separation of pure and mixed mania. The inclusion of a diagnostic seasonal specifier for DSM-IV, which is currently based on seasonal patterns for depression might be expanded to include seasonal patterns for mania. Boundaries between subtypes may be 'fuzzy' rather than crisp, and graded approaches could be considered. With the continued development of new tools, such as imaging and genetics, alternative approaches to diagnosis other than the purely symptom-centric paradigms might be considered.

Frequency of dysphoria and mixed states

BACKGROUND

Mixed states are a complex entity in the field of mood disorders. Dysphoria has been advocated as an important clinical dimension of mixed states. The objective of this work is to study the frequency of dysphoria within a population of patients with DSM-IV major depressive and/or manic episodes and to determine if it may help establish diagnostic criteria for subthreshold cases of depressive or manic mixed states.

SAMPLING AND METHODS

A total of 165 patients were assessed using the Mini International Neuropsychiatric Interview complemented by a section defining dysphoria as a constellation of 3 among 4 symptoms (inner tension, irritability, aggressive behavior and hostility).

RESULTS

When classifying patients according to the number of symptoms of the opposite polarity, changes in the frequency of dysphoria revealed a clear contrast between the 2 opposite manic and depressive poles and the full mixed state (DSM-IV definition). The frequency of dysphoria was 17.5% in pure depression, 22.7% in pure mania and 73.3% in full mixed state. Two threshold effects were identified: (1) the frequency of dysphoria increased from 17.5 to 61.1% (p = 0.002) when the number of manic symptoms in DSM-IV depressed patients increased from 0 to 1, and (2) dysphoria increased from 14.3 to 69.2% (p = 0.057) when the number of depressive symptoms increased from 2 to 3 in DSM-IV manic patients.

CONCLUSION

Dysphoria is strongly but not necessarily associated with mixed states. When used as a clinical marker for mixed states, dysphoria confirms the modern delimitations of sub-threshold mixed states by specifying the required number of symptoms of the opposite polarity (which could be lower for depressive mixed states than for manic mixed states). The study has limitations related to the inclusion of patients who are not drug-free, to the definition of dysphoria and to the sample size.

Epidemiology, diagnosis and management of mixed mania

The presence of depressive symptomatology during acute mania has been termed mixed mania, dysphoric mania, depressive mania or mixed bipolar disorder. Highly prevalent, mixed mania occurs in at least 30% of bipolar patients. Correct diagnosis is a major challenge. The DSM diagnostic criteria, the most widely adopted clinical convention, require a complete manic and complete depressive syndrome co-occurring for at least 1 week. However, recent alternative categorical and dimensional studies of manic phenomenology have shown that there are certain depressive symptoms or constellations that have special clinical importance when describing mixed states, such as depressed mood and anxiety symptomatology that do not overlap with manic symptoms. Patients with mixed mania are over-represented in the subgroup with severe and treatment-resistant symptoms. The course and prognosis of mixed mania are worse than that of pure manic forms in the medium and long term, with higher recurrence rates, higher frequency of co-morbid substance abuse and greater risk of suicidal ideation and attempts. Moreover, mixed manic episodes are usually associated with increased depression during follow-up, greater risk of rapid cycling course and higher prevalence of physical co-morbidities, principally related to thyroid function. All these factors are very relevant to selection of treatment. There are three crucial steps in the treatment of mixed mania--making the correct diagnosis, starting treatment early, and considering not only the acute state but also maintenance treatment and the patient's long-term outcome. Although challenging, acute mixed episodes are treatable. To date there have been no controlled studies devoted exclusively to treatment of mixed mania, and the only controlled data available therefore derive from sub-analyses of randomised clinical trials. Both short-term and maintenance treatments of patients with mixed mania require experience and usually involve the combination of different treatments. As a general rule, there is some consensus about discontinuing antidepressants during mixed mania. Olanzapine, aripiprazole or valproate semisodium (divalproex sodium) are first-line drugs for mild episodes; severe episodes of mixed mania usually require treatment with a combination of valproate semisodium or lithium plus an antipsychotic, preferably an atypical agent. Carbamazepine is also useful for the treatment of mixed mania. High-dose medications are sometimes needed to control the episode, and time to remission is usually longer than in pure mania. Importantly, patients with mixed manic episodes have more adverse events of psychopharmacological treatment. In some cases, electroconvulsive therapy is required.

Irritable psychomotor elation in depressed inpatients: a factor validation of mixed depression

BACKGROUND

Early authors described hypomanic symptoms as mixed features in depressive episode, but this syndrome has not been sufficiently explored in previous studies.

METHODS

958 consecutive depressed patients were assessed by using a standardized method in terms of 43 psychiatric symptoms at hospitalization.

RESULTS

A principal component analysis, followed by varimax rotation, extracted six interpretable factors: typical vegetative symptoms, depressive retardation/loss of feeling, hypomanic syndrome, anxiety, psychosis, and depressive mood/hopelessness. The extracted factor structure was relatively stable among several patient groups. There was no evidence that the hypomanic factor was exaggerated by antidepressant pretreatments before hospitalization. Bipolar diagnoses were associated with higher scores on depressive retardation and hypomanic symptoms, and a lower score on anxiety.

LIMITATIONS

Psychiatric syndromes and their interrelationships, found in the present study, may be strongly influenced by the rating instrument used. The sample of this study was depressed inpatients. The results should not be generalized for depressed outpatients or epidemiological depressed populations.

CONCLUSIONS

Hypomanic symptoms, as characterized by the flight of ideas, racing thought, increased drive, excessive social contact, irritability, and aggression are a salient syndrome in acutely ill depressed patients, lending support to the factor validity of mixed depression. The symptoms may not be related to pretreatments with antidepressants, or comorbidity of substance abuse, suggesting that they reflect various natural phenomenological manifestations of depressive episodes. Anxiety is unlikely to play a major role in the core phenomenological features of mixed depression. Hypomanic symptoms during a depressive episode were more represented in bipolar disorders, which may serve for further clarifications of latent bipolarity in unipolar depression, and prediction of switch into maniform states under biological depression treatments.

Dimensions of mania: differences between mixed and pure episodes

OBJECTIVE

The presence of at least five dimensions in mania has recently been established. This study extends previous findings by comparing the dimensions of pure vs. mixed mania.

MATERIALS AND METHOD

One hundred and three inpatients with bipolar I disorder, manic or mixed (DSM IV), were assessed with SCID-I, YMRS and HDRS-21. The five-factor solution found after applying factorial analysis with Varimax rotation was compared between manic and mixed patients.

RESULTS

There were differences between pure mania and mixed states on factor 1 (depression) and factor 3 (hedonism). There was a tendency to present higher values on factor 5 (activation) in the pure manic group. No differences were found in factor 2 (dysphoria) and factor 4 (psychosis).

DISCUSSION

Hedonism and activation dimensions are present to a lesser degree in mixed states. Although the principal difference between mixed and pure bipolar disorder is the existence of depressive symptoms, the depressive dimension is strongly present in patients with pure mania.

CONCLUSIONS

There is need to search for core depressive symptoms in all patients suffering from mania and to evaluate their outcome in clinical trials.

A retrospective comparison of inpatients with mixed and pure depression

Some authors advocate a broadening of the narrow concept of mixed episodes in the direction of mania leading to the concept of mixed mania, and in the direction of depression leading to the concept of mixed depression. The latter has been little investigated so far. In the present article, we retrospectively compare 49 patients with pure depression with 51 patients with mixed depression in terms of socio-demographic and clinical variables in order to contribute to the validation of the distinction between mixed and pure depression. Supporting this distinction, we observed that mixed depressive patients more frequently had past histories of bipolar disorder and alcohol abuse and had longer durations of hospital stay. These last two points remain significant even when we control for the effect of the association with bipolarity.

Long-term inter-episode stability of syndromes underlying mania

OBJECTIVE

To explore the stability of diverse manic presentations across manic recurrences.

METHOD

A total of 253 bipolar patients who experienced two or more hospitalizations, because of consecutive manic (or mixed) episodes, during a 20-year period were included. All patients had second hospitalizations with an mean interval of 773 days, while 126 and 91 patients had third and fourth hospitalizations with mean intervals of 1559 and 2237 days from the index hospitalization, respectively. Seven symptom scores, previously factor-validated, were calculated.

RESULTS

Depressive mood, irritable aggression, psychomotor/thought inhibition, mania, emotional lability/agitation and psychosis were moderately correlated across the index and subsequent hospitalizations.

CONCLUSION

A majority of diverse manic presentations were stable across manic recurrences. The stability was not restricted to two consecutive recurrences but appeared widespread over the long-term course of bipolar disorder. The finding may serve for the development of more effective long-term treatment strategies and a clinically more reasonable subtyping of mania.

Frequency of manic symptoms during a depressive episode and unipolar 'depressive mixed state' as bipolar spectrum

OBJECTIVE

To report the frequency of intra-episode manic symptoms in depressive episodes, and to evaluate unipolar depressive mixed state (DMS) as bipolar spectrum.

METHOD

A total of 958 (863 unipolar, 25 bipolar II, and 70 bipolar I) depressive in-patients were assessed in terms of manic symptoms at admission, and several clinical variables using standardized methods.

RESULTS

The frequency of manic symptoms (flight of idea, logorrhea, aggression, excessive social contact, increased drive, irritability, racing thoughts, and distractibility) was significantly higher in bipolar depressives than in unipolar depressives. Unipolar depressives with DMS - defined as having two or more manic symptoms - had more similarities to bipolar depressives than to other unipolar depressives in clinical variables such as onset age, family history of bipolar disorder, and possibly suicidality.

CONCLUSION

Depressive mixed state is frequent, particular in bipolar depressives. Unipolar depressives with DMS may be better classified into bipolar spectrum.