Bipolar disorder function

Depression occurring as part of bipolar disorder may be severe and accompanied by ideas of guilt and hopelessness, an inability to function at work because of poor concentration and psychomotor retardation or agitation, poor judgement and suicidal ideation. The lifelong risk of suicide in people with this condition is as high as 15%. Factors associated with suicide risk include alcohol misuse, marital separation or divorce, living alone and unemployment, and these are all common secondary consequences of the illness. 

Bipolar disorders have been categorized into bipolar I disorder, bipolar II disorder, and bipolar disorder, not otherwise specified (NOS). Bipolar I disorder is characterized by one or more manic or mixed mood episodes. Bipolar II disorder is characterized by one or more major depressive episodes and at least one hypomanic episode. Hypomania is an abnormally and persistently elevated, expansive, or irritable mood, but not of sufficient severity to cause significant impairment in social or occupational function and does not require hospitalization. Most epidemiologic studies have looked at bipolar disorder of all types (bipolar I and bipolar II), or the bipolar spectrum, which includes all clinical conditions thought to be closely related to bipolar disorder. The lifetime prevalence of bipolar I disorder is estimated to be between 0.3% and 2.4%. The lifetime prevalence of bipolar II disorder ranges from 0.2% to 5%. When including the bipolar spectrum, the lifetime prevalence is between 3% and 6.5%.1... 

A single enzyme, inositol monophosphatase, leads to loss of the remaining phosphate and the regeneration of free inositol. This enzyme exhibits similar affinities for all five of the equatorial inositol monophosphate hydroxyls. Inositol 2-phosphate, which is not produced in this degra-dative pathway, is a poor substrate, a property that is probably attributable to its axial configuration. The enzyme is inhibited by Li+ in an uncompetitive manner i.e. the degree of inhibition is a function of substrate concentration. The putative link between the ability of Li+ to interfere with phosphoinositide turnover and its therapeutic efficacy in the treatment of bipolar disorders is discussed in Box 20-1 and Chapter 55. It should be noted that unlike most other tissues, brain can synthesize inositol de novo by the action of inositol monophosphate synthase, which cyclizes glucose 6-phosphate to form I(3)P. The enzyme has been localized immunohistochemically to the brain vasculature. 

The positive symptoms are the most responsive to antipsychotic medications, such as chlorpromazine or halo-peridol. Initially, these drugs were thought to be specific for schizophrenia. However, psychosis is not unique to schizophrenia, and frequently occurs in bipolar disorder and in severe major depressive disorder in which paranoid delusions and auditory hallucinations are not uncommon (see Ch. 55). Furthermore, in spite of early hopes based on the efficacy of antipsychotic drugs in treating the positive symptoms, few patients are restored to their previous level of function with the typical antipsychotic medications [2]. 

Kravaiiti, E., Dixon, T., Frith, C., Murray, R., and McGuire, P. (2005) Association of symptoms and executive function in schizophrenia and bipolar disorder. Schizophr. Res. 74, 221-231. 

In addition to treating insomnia, gabapentin has been used to treat epilepsy, anxiety disorders, and bipolar disorder. It is generally well tolerated with sedation and headaches being the only prominent side effects. Because gabapentin is excreted unchanged in urine, it does not require metabolism by the liver. It is therefore easily eliminated by elderly patients and those with liver disease, although it should be used with caution in those with poor renal (kidney) function. 

Lithium is used in the prophylaxis and treatment of mania and in the prophylaxis of bipolar disorders and recurrent depression. Lithium should be stopped 24 hours before major surgery but the normal dose can be continued for minor surgery, with careful monitoring of fluids and electrolytes. After major surgery, renal function is reduced and this may compromise clearance of lithium. Lithium is a drug with a narrow therapeutic index and it should be avoided if possible in patients with renal impairment. Renal function should be tested before initiating treatment. If lithium is given to patients with renal impairment, a reduced dose should be used and serum lithium concentrations should be monitored closely. 

A great many physical and mental disorders develop because of a malfunction in the nervous system. Some examples are Alzheimer s disease, schizophrenia, Parkinson s disease, Huntington s chorea, and bipolar disorder. Most of the effects produced by recreational drugs, such as alcohol, heroin, and cocaine, are also a result of changes in the way the nervous system functions. Today, scientists have a reasonably good understanding of the way in which the nervous system operates and how many types of chemicals affect this operation. 

Blumberg, H., Kaufman, J., Martin, A., and Peterson, B. (2001) Structural and functional MRI studies in children, adolescents, and adults with bipolar disorder. Presented at the Childhood Depression A Critical Review Conference. Banbury Center, NY Cold Spring Harbor Laboratory. 

Chapter /, Modem Psychopharmaceuticals, written by Dr Hossein Fatemi, and Chapter 5, Psychopharmaceuticals and the Treatment of Mental Disorders, provide succinct, up to date, and well-referenced information on how to use the major classes of psychotropic drugs. The latter chapter discusses in a frank and balanced manner the ambivalence towards the use of pharmacologic agents in mental disorders felt by some, and the limitations on the achievements of current drugs as ideal therapies for schizophrenia, bipolar disorder and major depression in particular. Clearly, much has been accomplished, but many needs, especially for prevention of relapse, removal of specific types of symptoms, and restoraton of work and social function, remain to be accomplished by drug and psychosocial therapies. 

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