- Email: [email protected]
Chronic pain and depression. II. Symptoms of anxiety in chronic low back pain patients and their relationship to subtypes of depression
289
Pain, 22 (1985) 289-294 Elsevier
PAI 00761
Chronic Pain and Depression. II. Symptoms of Anxiety in Chronic Low Back Pain Patients and their Relations~p to Subtypes of Depression K. Ranga Rama Krishnan *, Randal D. France **I, Susan Pelton *, Una D. McCann **, Jonathan Davidson * and Bruno J. Urban * * Duke Uniuersiry Medical Center, Durham. NC 27710, and ** Stanford Unioersrty, Stanford, CA (U.S.A.) (Received
22 August
1984, revised received 20 December
1984, accepted
31 January
1985)
Summary 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.
An association between chronic pain and depression has been recognized for a long time [3]. A similar association has been recognized in terms of anxiety disorders [7,9,10]. Studies of patients with anxiety neurosis have shown that a significant number of these patients have pain complaints [lo]. In fact, the incidence of pain complaints amongst patients with anxiety neurosis of generalized anxiety disorder is often greater than that seen amongst patients with major depression [ll]. Further, patients with depresssion who have pain complaints are reported to have a high incidence of both vegetative and psychic anxiety [11,12]. It has been suggested
’ Reprints to: Randal D. France, M.D., Assistant Center, Box 3903, Durham, NC 27710, U.S.A.
030~3959/85/$03.30
Professor
0 1985 Elsevier Science Publishers
of Psychiatry,
B.V. (Biomedical
Duke
Division)
University
Medical
that the aches and pains seen in patients with depression are due to tense muscles secondary to anxiety [12]. Merskey and Boyd, in a study of chronic pain, found that 2% of women with chronic pain received a diagnosis of anxiety disorder [9]. However, there have been no systematic studies of symptoms of anxiety in patients with chronic pain syndromes. In an attempt to elucidate the relationship between symptoms of anxiety and low back pain, we examined the incidence of symptoms of anxiety using the Hamilton Anxiety Scale [5] in a group of chronic low back pain patients described in the preceding paper.
Method
Seventy-one consecutive chronic low back pain patients were studied. The characteristics of this group of patients have been described in the preceding paper. Thirty-one patients had Research Diagnostic Criteria (RDC) major depression, 8 patients had minor depression and 18 satisfied criteria for intermittent depressive disorder. None of the patients had any other psychiatric disorder (using RDC criteria). In addition to the diagnostic interview, ail patients were also evaluated by one of us (RK) using the Hamilton Anxiety Scale modified so that somatic symptoms were separately rated as muscular and/or sensory [2]. This is a 1Citem scale which has been used widely in patients with anxiety disorders and patients with depression. The presence or absence of organic findings was done as in the preceding paper.
Results
The patient characteristics have been described in the preceding paper. Table I shows an item analysis of the Hamilton Anxiety Scale between patients with major depression with and without organic features. There were no significant differences on any of the items using the Mann-W~tney test except patients without organic features had more respiratory, autonomic symptoms and cardiovascular symptoms. Table II shows an item analysis of the Hamilton Anxiety Scale in chronic low back pain patients with various types of depression. Anxious mood was greater in patients with major depression than in any other group of patients. Tension was more again in patients with major depression. This was, however, not significantly more than patients with minor depression. The item ‘tension’ refers to feelings of tension, inability to relax, startle response, trembling, feelings of restlessness, etc. Patients with major depression had significantly higher scores on the item ‘fear’ which refers to symptoms such as fear of dark, being left alone, traffic, crowds, etc. The item ‘insomnia’ in the Hamilton Anxiety Scale refers to any disturbance in sleep. There was no difference between any of the groups except those with major depression had more severe disturbance of sleep than those without depression.
291 TABLE
I
HAMILTON
ANXIETY
item analysis
of patients
with chronic
pain and depression
with and without
Orga!k
Anxious mood Tension Fears insomnia Cognitive Depressed mood General somatic (muscular) Generat somatic (sensory) Cardiovascular Resptratory ~~stro~ntestina~ Genito-urinary Autonomic symptoms Behavior at interview
Not organic
Mean
K-
Mean
S.D.
2.10 2.00 0.73 2.50 1.80 2.25 1.85 2.00 0.30 0.25 0.95 1.05 0.85 1.65
0.310 0.324 0.967 0.607 0.768 0.716 0.489 0 0.732 0.639 0,998 s ,099 0.933 0.587
2.2-I 1.875 0.909 2.091 1.435 2.364 t .636 2.18 1.09 1.272 0.909 0.727 1.546
0.467 0.354 0.831 0.944 0.820 0.505 0.809 0.603 1.136 1.272 1.045 1.104 0.688 0.467
using Mann-Whitney
findings. P
Major depression
Item
NS = P 3>0.05. Exact ‘P’ obtained
organic
2-tailed
test corrected
1.727
~ NS NS NS NS NS NS NS NS 0.03 0.01 NS NS 0.03 NS
for ties.
Cognitive disturbance which refers prima~ly to concentration difficulties and poor memory was more in patients with major depression than those with other types of depression and those without depression, Patients with minor depression had more concentration difficulties than those with intermittent depressive disorder (this was not statistically significant). Patients with depression, irrespective of the type, had more general somatic sensory symptoms such as tinnitus, blurring of vision, hot and cold flushes, pricking sensations. etc., than those patients without depression. Patients with major depression had more than those with minor or intermittent depression. General somatic symptoms (muscular) such as muscular pains and aches, stiffness, muscular twitching, etc. were again more in patients with depression. There was no difference between patients with and without organic findings. Patients with major depression had more than those with intermittent depressive disorder. Gastrointestinal symptoms such as difficulty in swallowing, dyspepsia, constipation, looseness of bowels, etc. were more in patients with major and minor depression. Genito-urinary symptoms such as frequency of micturition, urgency of micturition, amenorrhea. loss of erection, impotence, premature ejaculation etc. were primarily seen in patients with major and minor depression. There was no difference between patients with and without organic findings. Autonomic symptoms such as dry mouth, flushing, pallor, tendency to sweat, etc. were again seen more in patients with major depression and least in those without depression.
0.38
0.91
0.54
1.10
1.68
NS = P > 0.05. Exact ‘P ’ obtained
using Mann-
1.38 0.5 0.62 0.63 0.25
0.36 0.96 1.02 1.00 1.10
2.06 0.58 0.61 0.94 0.94
(sensory) Cardiovascular Respiratory Gastrointestinal Genito-urinary Autonomic symptoms Behavior at interview
1.25
0.62
1.77
Whitney
1.63
1.87 1.87 0 2.00 0.75 1.50
0.37 0.50 0.91 0.75 0.79 0.64
2.16 2.12 0.81 2.35 1.68 2.29
Anxious mood Tension Fears Insomnia Cognitive Depressed mood General somatic (muscular) Genera1 somatic
0.75
0.74
0.92 0.93 0.91 0.92 0.71
1.17
0.28
1.11 0.28 0.16 0.06 0.10
0.83
1.77 1.77 0.28 1.94 0.55 1.11
for ties.
0.86
0.46
0.97 0.67 0.51 0.24 0.40
0.86
0.54 0.42 0.67 0.87 0.92 0.68
Intermittent depression
and chronic
test corrected
1.04
0.35 0.35 0 0.93 0.88 0.53
2-tailed
Minor depression
types of depression
Major depression
with different
SCALE
Item
RATING
of patients
Item analysis
II
HAMILTON
TABLE
0.79
0.29
0.43 0.21 0.14 0 0
0.21
1.71 1.42 0.35 1.50 0.07 0.36
0.90
0.73
0.85 0.58 0.34 0 0
0.58
0.61 0.85 0.84 1.29 0.27 0.49
No depression
pain.
0.010 0.0007
NS NS NS NS
NS NS 0.034 NS
0.0000 O.oooO
NS
0.001
NS
0.001 0.003
NS
NS
NS
NS
NS
NS
NS NS
NS NS NS
0.002 NS 0.042 0.0400 0.0000
NS
0.24 NS 0.093 0.016 NS
0.014
2 vs. 4
2 vs. 3
1 vs. 4
0.004
0.0001 NS NS o.ooo9 0.09
0.0002
0.007 0.013 0.032 NS 0.0001 0.0000
1 vs. 3
0.04
0.008 NS NS NS NS
NS
NS NS NS NS 0.013 0.004
1 vs. 2
NS
NS
0.033 NS NS NS NS
0.022
NS NS 0.003
NS
NS NS
3 vs. 4
293
Patients with major depression exhibited more anxiety than any other group during the interview. Patients with minor depression differed from those with intermittent depression on only one item: gastrointestinal symptoms. Patients with minor depression have more gastrointestinal symptoms than those without intermittent depression. Patients with intermittent depressive disorder differed significantly from those without depression or depressed mood and general somatic symptoms. Patients with minor depression differed from those without depression in all items except anxious mood, tension, fear, insomnia, cardiovascular, genito-urinary and autonomic symptoms. Patients with major depression differed significantly from those with minor depression on the following items: anxious mood. cognitive function. depressed mood, general somatic (sensory) and autonomic symptoms. Patients with major depression differed significantly from those with intermittent depressive disorders on all items except insomnia, cardiovascular and respiratory symptoms. Patients with major depression differed significantly from those without depression on all items except cardiovascular and respiratory symptoms.
Discussion In this study we have shown that anxious mood and other symptoms of anxiety are commonly seen in patients with chronic low back pain. The symptoms of anxiety are more common in those with associated 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. Previous studies of chronic low back pain have primarily focussed on the symptoms of depression. The finding that symptoms of anxiety occur commonly in patients with chronic low back pain, especially those with depression, arouses interest as to the role of anxiety in altering the perception of pain in these patients. The occurrence of more anxiety in patients with depression with aches and pain is supportive of this possibility [12]. Hall and Stride [4] have shown that patients with anxiety neurosis tend to perceive pain, react earlier and make a verbal report of pain earlier than normal controls. Similarly, Chapman et al. [l] and Malmo and Shagass [8] have also shown that ‘neurotic’ patients have a greater degree of reactivity to pain. Hemphill et al. [6] showed that patients with anxiety neurosis tend to perceive pain earlier than any other clinical group. Patients with melancholia on the other hand have a lowered reactivity to pain and tend to perceive pain later than normals [4,6]. It is unclear whether these melancholic patients had associated anxiety or not [4]. However, Hall and Stride [4] have shown that some patients with depression have a low tolerance to pain. Whether these patients had symptoms of anxiety or not has not been studied. Studies to assess the relationship between alteration of pain threshold and anxiety are needed in these patients.
294
The beneficial use of relaxation treatment, biofeedback, in chronic low back pain may be due partially to both a reduction in anxiety and in muscular tension. Studies are needed to examine this potential relationship, Further studies regarding the role of symptoms of anxiety in chronic low back pain need to explore whether particular classes of antidepressants such as monoamine oxidase inhibitors which have been reported to be effective in patients with depression and anxiety are efficacious in the treatment of depression in these patients. Future studies also need to assess the relationship between severity of pain and symptoms of anxiety.
References 1 Chapman, W.P., Finesinger, J.E. and Jones, CM., Pam in ncur~irculato~ asthenia, combat fatigue and anxiety neurosis, J. clin. Invest., 25 (1947) 890-897. 2 Davidson, J.R.T. and Turnbull, C.D., The importance of dose in isocarboxazid therapy, J. chn. Psychiat., 45 (1984) 49-52. 3 France, R.D. and Houpt, J.L.. The clinical concepts of chronic pain, Gen. Hosp. Psychiat., 6 (1984) 37-41. 4 Wall, K.R.L. and Stride, E., The varying response to pain in psychiatric disorders, Brit. J. med. Psychol., 27 (1954) 48-60. 5 Hamilton, M.. The assessment of anxiety states by rating. &it. J. med. Psychof., 32 (7959) 50-55. in depressive and 6 Hemphill, R.E., Hall. K.R.L. and Crookes. T.G., Fatigue and pain tolerance psychosomatic patients, J. ment. Sci., 98 (1952) 433-440. 7 Large, R.G., The psychiatrist and the chronic Pain patients, 172 ancedotes, Pain 9 (1980) 253-263. 8 Malmo, R.B. and Shagass, C., Reaction to stress in anxiety and early schizophrenia, J. Personality, 19 (1980) 359-363. 9 Merskey, H. and Boyd, D., Emotional adjustment and chronic pain, Pain, 5 (1978) 173-178. 10 Spear, F.G., Pain in psychiatric patients, J. psychosom. Res., 11 (1967) 187-193. 11 Von Knorring, L,, The experience of pain in depressed patients. A clinical and experimental study, Neuropsychobiology, l(1975) 155-165. 12 Von Knorring, L., Pert%, C., Eisemann, M., Erickson, V. and Perris, H., Pain as a symptom in depressive disorders. (1983) 377-384.
H. Relatjons~p
to personality
traits
as assessed
by means
of KSP,
Pain,
17
Pain, 22 (1985) 289-294 Elsevier
PAI 00761
Chronic Pain and Depression. II. Symptoms of Anxiety in Chronic Low Back Pain Patients and their Relations~p to Subtypes of Depression K. Ranga Rama Krishnan *, Randal D. France **I, Susan Pelton *, Una D. McCann **, Jonathan Davidson * and Bruno J. Urban * * Duke Uniuersiry Medical Center, Durham. NC 27710, and ** Stanford Unioersrty, Stanford, CA (U.S.A.) (Received
22 August
1984, revised received 20 December
1984, accepted
31 January
1985)
Summary 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.
An association between chronic pain and depression has been recognized for a long time [3]. A similar association has been recognized in terms of anxiety disorders [7,9,10]. Studies of patients with anxiety neurosis have shown that a significant number of these patients have pain complaints [lo]. In fact, the incidence of pain complaints amongst patients with anxiety neurosis of generalized anxiety disorder is often greater than that seen amongst patients with major depression [ll]. Further, patients with depresssion who have pain complaints are reported to have a high incidence of both vegetative and psychic anxiety [11,12]. It has been suggested
’ Reprints to: Randal D. France, M.D., Assistant Center, Box 3903, Durham, NC 27710, U.S.A.
030~3959/85/$03.30
Professor
0 1985 Elsevier Science Publishers
of Psychiatry,
B.V. (Biomedical
Duke
Division)
University
Medical
that the aches and pains seen in patients with depression are due to tense muscles secondary to anxiety [12]. Merskey and Boyd, in a study of chronic pain, found that 2% of women with chronic pain received a diagnosis of anxiety disorder [9]. However, there have been no systematic studies of symptoms of anxiety in patients with chronic pain syndromes. In an attempt to elucidate the relationship between symptoms of anxiety and low back pain, we examined the incidence of symptoms of anxiety using the Hamilton Anxiety Scale [5] in a group of chronic low back pain patients described in the preceding paper.
Method
Seventy-one consecutive chronic low back pain patients were studied. The characteristics of this group of patients have been described in the preceding paper. Thirty-one patients had Research Diagnostic Criteria (RDC) major depression, 8 patients had minor depression and 18 satisfied criteria for intermittent depressive disorder. None of the patients had any other psychiatric disorder (using RDC criteria). In addition to the diagnostic interview, ail patients were also evaluated by one of us (RK) using the Hamilton Anxiety Scale modified so that somatic symptoms were separately rated as muscular and/or sensory [2]. This is a 1Citem scale which has been used widely in patients with anxiety disorders and patients with depression. The presence or absence of organic findings was done as in the preceding paper.
Results
The patient characteristics have been described in the preceding paper. Table I shows an item analysis of the Hamilton Anxiety Scale between patients with major depression with and without organic features. There were no significant differences on any of the items using the Mann-W~tney test except patients without organic features had more respiratory, autonomic symptoms and cardiovascular symptoms. Table II shows an item analysis of the Hamilton Anxiety Scale in chronic low back pain patients with various types of depression. Anxious mood was greater in patients with major depression than in any other group of patients. Tension was more again in patients with major depression. This was, however, not significantly more than patients with minor depression. The item ‘tension’ refers to feelings of tension, inability to relax, startle response, trembling, feelings of restlessness, etc. Patients with major depression had significantly higher scores on the item ‘fear’ which refers to symptoms such as fear of dark, being left alone, traffic, crowds, etc. The item ‘insomnia’ in the Hamilton Anxiety Scale refers to any disturbance in sleep. There was no difference between any of the groups except those with major depression had more severe disturbance of sleep than those without depression.
291 TABLE
I
HAMILTON
ANXIETY
item analysis
of patients
with chronic
pain and depression
with and without
Orga!k
Anxious mood Tension Fears insomnia Cognitive Depressed mood General somatic (muscular) Generat somatic (sensory) Cardiovascular Resptratory ~~stro~ntestina~ Genito-urinary Autonomic symptoms Behavior at interview
Not organic
Mean
K-
Mean
S.D.
2.10 2.00 0.73 2.50 1.80 2.25 1.85 2.00 0.30 0.25 0.95 1.05 0.85 1.65
0.310 0.324 0.967 0.607 0.768 0.716 0.489 0 0.732 0.639 0,998 s ,099 0.933 0.587
2.2-I 1.875 0.909 2.091 1.435 2.364 t .636 2.18 1.09 1.272 0.909 0.727 1.546
0.467 0.354 0.831 0.944 0.820 0.505 0.809 0.603 1.136 1.272 1.045 1.104 0.688 0.467
using Mann-Whitney
findings. P
Major depression
Item
NS = P 3>0.05. Exact ‘P’ obtained
organic
2-tailed
test corrected
1.727
~ NS NS NS NS NS NS NS NS 0.03 0.01 NS NS 0.03 NS
for ties.
Cognitive disturbance which refers prima~ly to concentration difficulties and poor memory was more in patients with major depression than those with other types of depression and those without depression, Patients with minor depression had more concentration difficulties than those with intermittent depressive disorder (this was not statistically significant). Patients with depression, irrespective of the type, had more general somatic sensory symptoms such as tinnitus, blurring of vision, hot and cold flushes, pricking sensations. etc., than those patients without depression. Patients with major depression had more than those with minor or intermittent depression. General somatic symptoms (muscular) such as muscular pains and aches, stiffness, muscular twitching, etc. were again more in patients with depression. There was no difference between patients with and without organic findings. Patients with major depression had more than those with intermittent depressive disorder. Gastrointestinal symptoms such as difficulty in swallowing, dyspepsia, constipation, looseness of bowels, etc. were more in patients with major and minor depression. Genito-urinary symptoms such as frequency of micturition, urgency of micturition, amenorrhea. loss of erection, impotence, premature ejaculation etc. were primarily seen in patients with major and minor depression. There was no difference between patients with and without organic findings. Autonomic symptoms such as dry mouth, flushing, pallor, tendency to sweat, etc. were again seen more in patients with major depression and least in those without depression.
0.38
0.91
0.54
1.10
1.68
NS = P > 0.05. Exact ‘P ’ obtained
using Mann-
1.38 0.5 0.62 0.63 0.25
0.36 0.96 1.02 1.00 1.10
2.06 0.58 0.61 0.94 0.94
(sensory) Cardiovascular Respiratory Gastrointestinal Genito-urinary Autonomic symptoms Behavior at interview
1.25
0.62
1.77
Whitney
1.63
1.87 1.87 0 2.00 0.75 1.50
0.37 0.50 0.91 0.75 0.79 0.64
2.16 2.12 0.81 2.35 1.68 2.29
Anxious mood Tension Fears Insomnia Cognitive Depressed mood General somatic (muscular) Genera1 somatic
0.75
0.74
0.92 0.93 0.91 0.92 0.71
1.17
0.28
1.11 0.28 0.16 0.06 0.10
0.83
1.77 1.77 0.28 1.94 0.55 1.11
for ties.
0.86
0.46
0.97 0.67 0.51 0.24 0.40
0.86
0.54 0.42 0.67 0.87 0.92 0.68
Intermittent depression
and chronic
test corrected
1.04
0.35 0.35 0 0.93 0.88 0.53
2-tailed
Minor depression
types of depression
Major depression
with different
SCALE
Item
RATING
of patients
Item analysis
II
HAMILTON
TABLE
0.79
0.29
0.43 0.21 0.14 0 0
0.21
1.71 1.42 0.35 1.50 0.07 0.36
0.90
0.73
0.85 0.58 0.34 0 0
0.58
0.61 0.85 0.84 1.29 0.27 0.49
No depression
pain.
0.010 0.0007
NS NS NS NS
NS NS 0.034 NS
0.0000 O.oooO
NS
0.001
NS
0.001 0.003
NS
NS
NS
NS
NS
NS
NS NS
NS NS NS
0.002 NS 0.042 0.0400 0.0000
NS
0.24 NS 0.093 0.016 NS
0.014
2 vs. 4
2 vs. 3
1 vs. 4
0.004
0.0001 NS NS o.ooo9 0.09
0.0002
0.007 0.013 0.032 NS 0.0001 0.0000
1 vs. 3
0.04
0.008 NS NS NS NS
NS
NS NS NS NS 0.013 0.004
1 vs. 2
NS
NS
0.033 NS NS NS NS
0.022
NS NS 0.003
NS
NS NS
3 vs. 4
293
Patients with major depression exhibited more anxiety than any other group during the interview. Patients with minor depression differed from those with intermittent depression on only one item: gastrointestinal symptoms. Patients with minor depression have more gastrointestinal symptoms than those without intermittent depression. Patients with intermittent depressive disorder differed significantly from those without depression or depressed mood and general somatic symptoms. Patients with minor depression differed from those without depression in all items except anxious mood, tension, fear, insomnia, cardiovascular, genito-urinary and autonomic symptoms. Patients with major depression differed significantly from those with minor depression on the following items: anxious mood. cognitive function. depressed mood, general somatic (sensory) and autonomic symptoms. Patients with major depression differed significantly from those with intermittent depressive disorders on all items except insomnia, cardiovascular and respiratory symptoms. Patients with major depression differed significantly from those without depression on all items except cardiovascular and respiratory symptoms.
Discussion In this study we have shown that anxious mood and other symptoms of anxiety are commonly seen in patients with chronic low back pain. The symptoms of anxiety are more common in those with associated 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. Previous studies of chronic low back pain have primarily focussed on the symptoms of depression. The finding that symptoms of anxiety occur commonly in patients with chronic low back pain, especially those with depression, arouses interest as to the role of anxiety in altering the perception of pain in these patients. The occurrence of more anxiety in patients with depression with aches and pain is supportive of this possibility [12]. Hall and Stride [4] have shown that patients with anxiety neurosis tend to perceive pain, react earlier and make a verbal report of pain earlier than normal controls. Similarly, Chapman et al. [l] and Malmo and Shagass [8] have also shown that ‘neurotic’ patients have a greater degree of reactivity to pain. Hemphill et al. [6] showed that patients with anxiety neurosis tend to perceive pain earlier than any other clinical group. Patients with melancholia on the other hand have a lowered reactivity to pain and tend to perceive pain later than normals [4,6]. It is unclear whether these melancholic patients had associated anxiety or not [4]. However, Hall and Stride [4] have shown that some patients with depression have a low tolerance to pain. Whether these patients had symptoms of anxiety or not has not been studied. Studies to assess the relationship between alteration of pain threshold and anxiety are needed in these patients.
294
The beneficial use of relaxation treatment, biofeedback, in chronic low back pain may be due partially to both a reduction in anxiety and in muscular tension. Studies are needed to examine this potential relationship, Further studies regarding the role of symptoms of anxiety in chronic low back pain need to explore whether particular classes of antidepressants such as monoamine oxidase inhibitors which have been reported to be effective in patients with depression and anxiety are efficacious in the treatment of depression in these patients. Future studies also need to assess the relationship between severity of pain and symptoms of anxiety.
References 1 Chapman, W.P., Finesinger, J.E. and Jones, CM., Pam in ncur~irculato~ asthenia, combat fatigue and anxiety neurosis, J. clin. Invest., 25 (1947) 890-897. 2 Davidson, J.R.T. and Turnbull, C.D., The importance of dose in isocarboxazid therapy, J. chn. Psychiat., 45 (1984) 49-52. 3 France, R.D. and Houpt, J.L.. The clinical concepts of chronic pain, Gen. Hosp. Psychiat., 6 (1984) 37-41. 4 Wall, K.R.L. and Stride, E., The varying response to pain in psychiatric disorders, Brit. J. med. Psychol., 27 (1954) 48-60. 5 Hamilton, M.. The assessment of anxiety states by rating. &it. J. med. Psychof., 32 (7959) 50-55. in depressive and 6 Hemphill, R.E., Hall. K.R.L. and Crookes. T.G., Fatigue and pain tolerance psychosomatic patients, J. ment. Sci., 98 (1952) 433-440. 7 Large, R.G., The psychiatrist and the chronic Pain patients, 172 ancedotes, Pain 9 (1980) 253-263. 8 Malmo, R.B. and Shagass, C., Reaction to stress in anxiety and early schizophrenia, J. Personality, 19 (1980) 359-363. 9 Merskey, H. and Boyd, D., Emotional adjustment and chronic pain, Pain, 5 (1978) 173-178. 10 Spear, F.G., Pain in psychiatric patients, J. psychosom. Res., 11 (1967) 187-193. 11 Von Knorring, L,, The experience of pain in depressed patients. A clinical and experimental study, Neuropsychobiology, l(1975) 155-165. 12 Von Knorring, L., Pert%, C., Eisemann, M., Erickson, V. and Perris, H., Pain as a symptom in depressive disorders. (1983) 377-384.
H. Relatjons~p
to personality
traits
as assessed
by means
of KSP,
Pain,
17