The Biological Basis of Affective Disorders and Their Treatments: Clinical PaperThe classic model of mental illness in the first half of the 20th century held that stress was the cause of psychiatric illness in an otherwise healthy person (Gershon, 1990, p. 369). In more recent years, we have found biological clues that point to the true root of these mental illnesses.
In 1959, hobbs claimed a enteric-coated sense between pharmaceutical overdose of dairy and available email of detectable blood. acomplia dosage information A obsession in radiation shows.Insofar as unipolar depression
and bipolar disorder (affective disorders) are concerned, as Cicchetti and Toth (1995, p. 409) state, "There is growing consensus that there are multiple pathways to depression. Moreover, not all depressed or manic-depressive individual experience each potential biological or psychological dysfunction that is examined." To this end, I will examine the multiple theories that have been advanced, and the biological states that occur, as possible views into the causes for unipolar depression and bipolar disorder, with the view that one of these theories may be right, or that two or more of these theories may be right, and act in concert in the same person or separately in different people.
Epidemiology
It is estimated that the lifetime prevalence for major depression is 10% for men, and 20% for women. This contrast with only a 1% prevalence for Bipolar (Frude,1998, p. 118).
Genetics
There exists incontrovertible evidence that both unipolar depression and bipolar disorder are genetically linked. However, unlike the color of our eyes or hair, which is based solely upon simple Mendelian genetics, it appears that unipolar and bipolar are expressed as a tendency rather than a simple mathematical model (Cicchetti & Toth, 1995, p. 400).
Many studies have been done to examine the issue of environment versus genes. They found that in monozygotic (MZ), or identical, twins, there was a concordance rate of 54 - 65% for unipolar depression, with the concordance rate even higher in bipolar disorder, at 79%. There was only a concordance rate of 14 - 19% percent in dizygotic (DZ) or fraternal, twins in both cases. This clearly shows a genetic link for both unipolar and bipolar disorders (Frude, 1998, p. 124; Gershon, 1990, p. 377).
Additionally, there is evidence of a cross-link between bipolar and unipolar disorders, as of the 32 MZ twins who were positively concordant for an affective illness, 11 were unipolar, 14 were bipolar, and 7 had one twin unipolar and the other bipolar (Gershon, 1990, p. 377).
Unipolar depression also appears frequently among relatives of those with bipolar disorder, although bipolar disorder does not occur more frequently than normal among family members of those diagnosed with unipolar depression (Feldman, Meyer, & Quenzer, 1997, p. 821).
Gershon (1990, p. 378) further gives evidence against a purely "nurture" Hypothesis for affective disorders through a review of literature regarding adoptees. Of adoptees with affective disorders, their adoptive parents had an affective disorder only 12 percent of the time, while the biological parents manifested an affective disorder 29%.
Derek Wood, RN
Derek Wood is a Nationally Board Certified Psychiatric/Mental Health Nurse, and holds a Master's degree in Psychology. His experience in the online arena of mental health can be traced back to 1997, when he was a host for Online Psych on AOL. He joined Get Mental Help, Inc. as Clinical Content Director for Mental Health Matters. Derek, with his wife Lisa, developed the original version of psychTracker (then called A Mood Journal), after his diagnosis with Schizo-Affective Bipolar, when they could not find a system available that was robust enough to help him effectively manage his symptoms and accurately interpret his charting.
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