CSF monoamine metabolites in chronic pain.

Metabolites of selected neurotransmitters (5-HIAA, HVA and DOPAC) and beta-endorphin were measured in the CSF of 39 chronic pain patients and compared to controls. Twelve of the pain patients also fulfilled criteria for major depression. The concentration of 5-HIAA was increased in female but not male pain patients; there was no significant difference in the CSF concentrations of HVA and DOPAC. The presence of depression did not influence the concentrations of neurotransmitters. No correlation was found between the concentrations of monoamine metabolites and beta-endorphin. However, there was a positive correlation between 5-HIAA and HVA in controls and chronic pain patients without depression but not in depressed patients. It is concluded: chronic pain states are associated with elevation of CSF 5-HIAA in female patients; depression abolishes a positive correlation between 5-HIAA and HVA.

Chronic pain and depression. IV. DST as a discriminator between chronic pain and depression.

In an attempt to clarify the relationship between chronic pain and depression, the authors studied the plasma cortisol response to dexamethasone in a group of 73 consecutive chronic low back pain patients admitted to a pain unit and 34 consecutive patients admitted to an affective disorders unit with the principal diagnosis of primary major depression. Patients with chronic pain were evaluated as to the presence or absence of major depression and patients with primary major depression were evaluated as to the presence or absence of pain complaints as part of their presenting symptomatology. Chronic pain patients with major depression differed significantly from chronic pain patients without major depression (3.4 +/- 3.33 micrograms/dl versus 1.6 +/- 0.9 micrograms/dl, P less than 0.05). Chronic pain patients with major depression also differed from patients with primary major depression with pain complaints (3.4 +/- 3.3 micrograms/dl versus 10.7 +/- 8 micrograms/dl, P less than 0.0005). The values given are post-dexamethasone plasma cortisol levels. Patients having primary major depression with pain complaints do not significantly differ from patients having primary major depression without pain complaints. The dexamethasone suppression test may be a useful method in discriminating those patients with chronic pain versus those with primary major depression, chronic pain patients with major depression versus those with primary major depression and chronic pain patients with major depression versus those with chronic pain and no depression.

Chronic pain and depression. I. Classification of depression in chronic low back pain patients.

An association between chronic pain and depression has been recognized for a long time. However, the exact nature of this relationship remains unclear. The authors studied 71 patients for affective disorders and schizophrenia-lifetime version (SADS-L). Based on the interviews, we were able to identify 31 patients with major depression, 8 patients with minor depression and 18 with intermittent depressive disorder as defined by Research Diagnostic Criteria. Item analysis using the Hamilton Depression Rating Scale and the Montgomery-Asberg Depression Rating Scale showed that the items did not discriminate in patients with major depression the presence of organic findings. However, most of the items significantly discriminated between the various types of depression and patients without depression. The occurrence of clearly defined depression points to several avenues of research aimed at clarifying the incidence etiology and treatment of depression in these patients.

Chronic pain and depression. II. Symptoms of anxiety in chronic low back pain patients and their relationship to subtypes of depression.

The relationship between anxiety and chronic pain has been poorly studied. The authors studied the occurrence of symptoms of anxiety in chronic low back pain patients. Anxious mood and other symptoms of anxiety were commonly seen in patients with chronic low back pain. Symptoms of anxiety were more common in patients with depression, especially those with major depression. Anxious mood, tension and general somatic symptoms of the sensory type were more common than any other type of anxiety symptoms. The authors discuss the potential role of anxiety in chronic pain patients.