Family (genetic) studies in neurotic depression

Urinary levels of 3-methoxy-4-hydroxyphenylglycol predict symptom severity in selected patients with unipolar depression

There are preliminary biological data that support the validity of subtyping depressed patients by family history into depressive spectrum disease (DSD) and non-DSD groups. We hypothesized that a relatively homogeneous group of depressed patients might show an association between symptom severity and the norepinephrine metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG). Twenty-four patients with non-DSD depression showed a relationship between urinary levels of MHPG and the severity of several depressive symptoms. There were no associations between MHPG and symptom severity for 38 DSD patients. This study provides additional support for the validity of family history approaches to subtyping depression. The data also suggest that norepinephrine may be involved in some way in the pathogenesis of symptoms in non-DSD depression.

Low levels of MHPG in depressive spectrum patients

There is some preliminary laboratory support for the proposed classification of depressed patients into depressive spectrum disease (DSD) and non-DSD. This study explores whether there is a difference in the levels of the norepinephrine metabolite, MHPG, in DSD and non-DSD patients. MHPG levels from 38 DSD patients were compared with 24 non-DSD patients. After controlling for the influence of age and gender on MHPG, the DSD patients had MHPG levels that were lower than non-DSD patients; 1655 +/- 90 mg/day vs. 1965 +/- 174 mg/day, respectively; P = 0.05. This study provides additional laboratory support for the DSD subtype. Possible implications of this finding are discussed.

Detoxified alcoholics, major depressives and tyramine sulphate excretion

The excretion of tyramine sulphate after challenge with an oral load of tyramine was assessed in recently detoxified, clinically depressed alcoholics and a matched group of major depressives. Tyramine excretion in the alcohol group (mean 5.95 ± 3.28 mg/3 h SD) was in the range previously observed in controls and was significantly higher than in the matched depressives (mean 3.43 ± 2.37 mg/3 h SD). Tyramine sulphate excretion has been suggested as a genetic vulnerability marker for major depression. This study suggests that depression associated with alcohol withdrawal is not characterised by decreased tyramine sulphate excretion after oral tyramine challenge, such decreased conjugation only being present, perhaps, in those patients with pre- existing endogenous depressive vulnerability. Although a genetic link between alcoholism and depression exists, these results support the absence of such a link to major depression.

The genetics of neurotic-reactive depression: a reanalysis of Shapiro's (1970) twin study using diagnostic criteria

The present study explored the role of genetic factors in the development of neurotic depression. Case studies of 16 monozygotic (MZ) and 14 same-sex dizygotic (DZ) twins from Robert Shapiro's 1970 study of non-endogenous depression were rediagnosed by two raters blind to the zygosity and identity of each twin. Diagnoses were made using Research Diagnostic Criteria (RDC) and George Winokur's 1985 criteria for neurotic-reactive depression. When neurotic depression was operationally defined using Winokur's criteria plus RDC major or definite minor depression, the concordance rate for MZ twins was significantly greater than that for DZ twins. Our results contrast with Shapiro's negative findings, probably due to our use of formal diagnostic criteria and Shapiro's requirement that cotwins be hospitalized to be considered concordant. The present results suggest that genetic factors play a role in the etiology of at least some forms of neurotic depression.

Neurotic depression: a diagnosis based on preexisting characteristics

A neurotic depression is a depression in an emotionally unstable person. Secondary depressions to major personality disorders, neuroses, and drug use disorders fit the above definition. Likewise, primary depressions with a family history of alcohol (depression spectrum disease) are characterized by a long history of stormy life problems and, therefore, would fit the definition. Using these two preexisting characteristics, we examined a group of 401 neurotic depressives and compared them to 536 nonneurotic (endogenous) depressives. The neurotic depressives were younger and the neurotic patients had made more previous suicide attempts. They were less likely to show memory deficits or delusions and less likely to show symptom criteria of melancholia. They were more likely to have suicide thoughts at index. Treatment was more effective in the nonneurotic patients and such patients made fewer suicide attempts in follow-up. These differences confirm the validity of the distinction between neurotic and nonneurotic depression.