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Platelet 5-HT concentration and comorbid depression in war veterans with and without posttraumatic stress disorder
Journal of Affective Disorders 75 (2003) 171–179 www.elsevier.com / locate / jad
Research report
Platelet 5-HT concentration and comorbid depression in war veterans with and without posttraumatic stress disorder a, b ˇ *, Nela Pivac a , Miro Jakovljevic´ b , Marina Sagud ¨ ˇ Dorotea Muck-Seler , ´ ˇb Alma Mihaljevic-Peles a
ˇ ´ Institute, P.O. Box 180, HR-10002 Zagreb, Croatia Laboratory for Molecular Neuropharmacology, Ru)jer Boskovic b University Psychiatric Clinic, Clinical Hospital Centre Zagreb, Zagreb, Croatia Received 30 April 2001; received in revised form 21 January 2002; accepted 22 January 2002
Abstract Background: The serotonergic system is implicated in the pathophysiology of posttraumatic stress disorder (PTSD) and depression. The present study focused on platelet serotonin (5-HT) concentration and symptoms of comorbid depression in war veterans with or without PTSD. Methods: PTSD and depression were evaluated using Clinician Administered PTSD Scale, Davidson Trauma Scale, Montgomery–Asberg Depression Rating Scale and Hamilton Anxiety Scale. Sixty-five male drug-free war veterans (48 with PTSD and 17 without PTSD) and 65 age- and sex-matched healthy controls were studied. Results: Comorbid depression occurred in 54 and 31% of war veterans with PTSD and without PTSD, respectively. Platelet 5-HT concentration was similar in the groups of depressed and nondepressed war veterans with or without PTSD and healthy controls. Platelet 5-HT concentration was found to differ between war veterans with various degrees of appetite loss. A positive correlation was observed between platelet 5-HT concentration and severity of appetite loss in veterans with PTSD. There was no relationship between platelet 5-HT concentration and severity of other symptoms of PTSD or depression. Limitations: War veterans included in the study were outpatients. Conclusions: War veterans with PTSD had a high incidence of comorbid depression, that was not related to platelet 5-HT concentration. The marked relationship between platelet 5-HT concentration and severity of appetite loss, suggested that 5-HT system is involved in the regulation of appetite, at least in depressed war veterans with PTSD. 2002 Elsevier Science B.V. All rights reserved. Keywords: Posttraumatic stress disorder; War veterans; Depression; Platelet 5-HT; Appetite loss
1. Introduction Posttraumatic stress disorder (PTSD) is an illness *Corresponding author. Tel.: 1 385-1-456-1111; fax: 1 385-1456-1010. ¨ ˇ E-mail address: [email protected] (D. Muck-Seler).
of chronic course, high morbidity and treatment resistance. Combat exposure is the most frequent cause of PTSD in men, while sexual abuse is the most frequent precipitant of PTSD in women (Kaufman and Charney, 2000). The characteristic symptoms of PTSD involve mental reliving of the trauma, numbing the responsiveness to the external stimuli,
0165-0327 / 02 / $ – see front matter 2002 Elsevier Science B.V. All rights reserved. doi:10.1016/S0165-0327(02)00035-6
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avoidance of stimuli associated with trauma, and ´ increased arousal (Charney et al., 1993; Jakovljevic, 1998; Shalev, 2000). Depressive symptoms are common features in PTSD patients, and major depression is a frequent coexisting comorbidity in ´ 1998; Shalev, 2000). PTSD (Jakovljevic, The ethiology of PTSD is not clear. PTSD has been reported to be associated with the alterations in serotonergic (Davis et al., 1997; Maes et al., 1999), noradrenergic (Southwick et al., 1993; Maes et al., 1999), dopaminergic, opiate, CRH (Charney et al., 1993) systems and in altered activity of hypothalamic–pituitary–adrenal axis (Yehuda, 2000). Previous investigations of serotonergic function in war veterans with PTSD studied blood platelet serotonin (5-HT, 5-hydroxytryptamine) as a peripheral model for the central serotonergic neurones (Stahl, 1985; Andres et al., 1993). Unaltered platelet 5-HT uptake and 5-HT concentrations (Melˇ ˇ ˇ lman and Kumar, 1994; Cicin-Sain et al., 2000), decreased platelet monoamine oxidase (MAO) ac-
ˇ ˇ ˇ tivity (Davidson et al., 1985; Cicin-Sain et al., 2000), and reduced (Arora et al., 1993), increased (Maes et al., 1999), or unaltered (Maguire et al., 1998) 3 Hparoxetine binding to platelet membranes have been found in PTSD. Although 5-HT regulates a myriad of physiological and pathological functions (see Stahl, 1998), that could be disturbed in PTSD, there were no data about the relationship between blood platelet 5-HT and different symptoms of PTSD and comorbid depression. The aim of the present study was to elucidate the role of the serotonergic system in PTSD with comorbid depression. In this respect, we determined: (a) frequency of the occurrence of comorbid depression in male war veterans with or without PTSD; (b) correlation between different clinical scales for PTSD and depression and platelet 5-HT concentration; and (c) platelet 5-HT concentrations in war veterans with or without PTSD, subdivided by the presence of comorbid depression, and different depressive symptoms (concentration difficulties, loss of
Table 1 CAPS, DTS, MADRS and HAS scores in war veterans with or without PTSD subdivided according to the presence or absence of comorbid depression Scales
Scores (mean6S.D.) War veterans Without PTSD (17)
With PTSD (48)
Nondepressed (13)
Depressed (4)
Nondepressed (16)
Depressed (32)
CAPS Total B C D E (years)
32.3615.0 9.865.6 13.067.4 8.765.7 2.660.8
42.363.8 11.863.0 17.862.8 15.364.2 2.360.5
62.9610.5 a 18.664.6 a 22.665.0 a 20.664.3 a 4.862.0 a
66.1612.0 a 20.065.2 a 26.364.6 a 19.465.2 4.061.9
DTS Total Frequency Severity
22.0613.3 9.265.4 12.968.1
31.861.5 13.561.3 18.360.5
46.8610.8 b 21.865.8 c 25.066.1 d
51.7617.6 b 24.1612.2 29.369.8 d
7.965.7 9.565.3
17.061.6 18.061.8
11.063.3 13.366.0
19.963.9 17.266.3
MADRS HAS
B, reexperiencing symptoms; C, avoidance and numbing symptoms; D, hyperarousal symptoms; E, duration of disturbance. a P , 0.05 vs. the corresponding war veterans without PTSD (ANOVA and Tukey test). b P , 0.05 vs. the corresponding groups of war veterans without PTSD (ANOVA and Tukey test). c P , 0.05 vs. nondepressed subjects without PTSD (ANOVA and Tukey test). d P , 0.05 vs. the corresponding groups of war veterans without PTSD (ANOVA and Tukey test).
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appetite, inability to feel, insomnia, pessimistic thoughts, and suicidality), and in age- and sexmatched healthy controls.
2. Methods
2.1. Subjects The study included 65 Croatian male war veterans and 65 age-matched healthy male subjects (control subjects). The mean6S.D. age in the group of war veterans was 32.867.8 years (range 22–50 years), and in control subjects 31.468.1 years (range 20–56 years). After structured clinical interview, based on the DSM-IV criteria (American Psychiatric Association, 1994), performed by the experienced psychiatˇ ´ M. Sagud, ´ rists (M. Jakovljevic, A. Mihaljevicˇ war veterans were divided into two groups Peles), according to the Clinician Administered PTSD Scale (CAPS) in (a) 48 subjects with current chronic PTSD (CAPS scores . 50) and (b) 17 subjects without current PTSD (CAPS scores , 50). The frequency and severity of PTSD symptoms and anxiety were evaluated using Davidson Trauma Scale (DTS) and Hamilton Anxiety Scale (HAS), respectively. According to the Montgomery–Asberg Depression Rating Scale (MADRS), war veterans were further subdivided into groups with depression (total scores 5 15) and without depression (total scores , 15). The mean scores in particular scales for PTSD and depression are shown in Table 1. Depressive symptoms (loss of appetite, insomnia, inability to feel, concentration difficulties, suicidality, and pessimistic thoughts) were evaluated using MADRS, and war veterans were subdivided into two groups: without symptoms (score 0), or present symptoms (that included moderate, severe, and very severe symptoms). The different degrees of symptoms of appetite loss were subdivided into: (a) symptoms not present (score 0); (b) moderate (scores 1–2); and (c) severe (scores 3–4) symptoms. War veterans were outpatients, and some of them were included in an ongoing double-blind, multicentric study. Subjects who had suffered from major depression or other axis-I diagnosis before combat experience were excluded. None of the subjects had a secondary diagnosis of alcoholism or drug depen-
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dency. Nonpsychiatric medical comorbidity at the time of the survey was assessed by the response to interviewer questions. Headaches (18 subjects), back pains (seven subjects) and gastro-intestinal symptoms (five subjects) were the predominant somatic problems. Subjects with PTSD were drug-free for at least 2 weeks before sampling. Control subjects were mainly medical stuff, with no personal or family history of psychopathology, and no medical treatment. All participants gave their written consent.
2.2. Biochemical analysis Blood (4 ml) was drawn from cubical vein at 08:00 h in a plastic syringe with 1 ml of acid citrate dextrose anticoagulant. Platelet-rich-plasma (PRP) was obtained by centrifugation (935 3 g) for 70 s at room temperature. Platelets were sedimented by further centrifugation of PRP at 10 000 3 g for 5 min. The platelet pellet was washed with saline and centrifuged again. Platelet 5-HT concentrations were determined by ¨ ˇ the spectrofluorimetric method (Muck-Seler et al., 1988). Briefly, platelets were destroyed by sonication (20 kHz, amplitude 8 3 10 23 mm for 30 s). Specimens of standard, blank (water) and platelet sonicates were analysed in duplicate. All samples were deproteinized with 1 ml of 10% ZnSO 4 and 0.5 ml of 1 N NaOH. For the preparation of fluorophore, 0.2 ml of L-cysteine (0.1%) and 1.0 ml of orthophthalaldehyde (0.05%) were added to deproteinized samples. The measurement of the 5-HT fluorescence was performed on an Aminco-Bowman spectrofluorimeter. Platelet protein was determined by the method of Lowry et al. (1951).
2.3. Statistical analysis All results were expressed as mean6S.D. The differences between groups were assessed by oneway analysis of variance (ANOVA), followed by Tukey multiple comparison procedure. Student’s ttest was used when only two groups were compared. The correlation between platelet 5-HT and age, different clinical scales, or various degrees of depressive symptoms, was determined by Pearson’s coefficient of correlation. The frequency of the occurrence of depressive symptoms was determined by a x 2 test.
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3. Results The comorbid depression appeared in 54% of war veterans with PTSD and in 31% of veterans without PTSD (Fig. 1), with a greater frequency of depression ( x 2 5 7.79; df 5 1, P , 0.005) in veterans with PTSD. Table 1 shows different clinical scales for PTSD and depression in war veterans. Depressed veterans with PTSD had significantly higher scores (F 5 20.59; df 5 3,64; P , 0.001) of avoidance and numbing symptoms (CAPS subscale C) than nondepressed PTSD veterans (Table 1). One-way ANOVAs revealed significant differences in total scores in DTS (F 5 13.45; df 5 3,61; P , 0.001) and in subscales of trauma frequency (F 5 8.47; df 5 3,61; P , 0.001) and severity (F 5 12.65; df 5 3,61; P , 0.001). War veterans with PTSD had significantly higher (P , 0.05, Tukey) scores in total and both subscales of DTS, as compared to corresponding groups of war veterans without PTSD (Table 1). War veterans (1.2960.43 nmol / mg protein) and healthy controls (1.2160.21 nmol / mg protein) had similar (t 5 1.06; df 5 128; P 5 0.21, Student’s t-
test) platelet 5-HT concentration. There was no difference in platelet 5-HT concentration (F 5 0.77; df 5 2,127; P 5 0.46) between groups of war veterans with PTSD (1.2960.45 nmol / mg protein), without PTSD (1.2860.40 nmol / mg protein), and control subjects. Fig. 1 shows lack of significant difference (F 5 1.91; df 5 4,125; P 5 0.11) in platelet 5-HT concentration between healthy controls and war veterans with and without PTSD, subdivided further by the presence or absence of comorbid depression. There was no correlation between platelet 5-HT concentration and scores in clinical scales (Table 2). Platelet 5-HT concentration was not associated with age in war veterans (r 5 0.15; P 5 0.40) or in control subjects (r 5 2 0.07; P 5 0.71). In war veterans with PTSD, symptoms of pessimistic thoughts ( x 2 5 8.84, df 5 1; P 5 0.003), suicidality ( x 2 5 13.34; df 5 1; P 5 0.001), and loss of appetite ( x 2 5 3.77; df 5 1; P 5 0.05), occurred more frequently in depressed than in nondepressed veterans (Table 3). All veterans with PTSD had the symptoms of concentration difficulties and insomnia, while symptom of inability to feel was present
Table 2 The Pearson’s coefficient of correlation (r) between platelet 5-HT concentration and clinician administered PTSD scale (CAPS), DTS, MADRS and HAS scores in war veterans with or without PTSD Scales
Platelet 5-HT (nmol / mg protein) War veterans Without (17)
CAPS Total B C D E (years)
Fig. 1. Individual platelet 5-HT concentrations in controls and in war veterans with or without PTSD and comorbid depression. The mean value in each group is indicated by a horizontal line drawn through the corresponding data points.
DTS Total Frequency Severity MADRS HAS
PTSD With PTSD (48)
r
p
r
p
0.02 0.12 0.28 2 0.20 0.36
0.95 0.65 0.28 0.44 0.16
2 0.07 0.10 0.18 2 0.02 0.07
0.64 0.49 0.24 0.91 0.64
0.01 0.01 0.01
0.98 0.99 0.97
0.08 0.11 0.03
0.61 0.45 0.87
0.18 2 0.21
0.43 0.41
0.27 0.24
0.07 0.10
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Table 3 Platelet 5-HT (mean6S.D.) in healthy controls and in war veterans with or without PTSD (with or without depression) subdivided according to the presence or absence of depressive symptoms War veterans Platelet 5-HT (nmol / mg protein) Without PTSD (17)
With PTSD (48)
Nondepressed (13)
Depressed (4)
Nondepressed (16)
Depressed (32)
Symptoms Appetite loss Without Present
1.5060.31 (9) 1.0660.51 (4)
1.1460.22 (4)
1.0760.26 (12) 1.3560.49 (4)
1.2460.50 (13) 1.4560.46 (19)
Insomnia Without Present
1.3260.33 (2) 1.3360.48 (11)
1.1460.22 (4)
1.1460.34 (16)
1.3760.48 (32)
Inability to feel Not present Present
1.3460.22 (5) 1.3360.55 (8)
1.1460.22 (4)
0.9760.06 (2) 1.1660.34 (14)
0.9960.64 (2) 1.3960.47 (30)
Concentration difficulties Without Present
1.3360.25 (4) 1.3360.51 (9)
1.1460.22 (4)
1.1460.34 (16)
1.3760.48 (32)
Pessimistic thoughts Without Present
1.3960.21 (7) 1.2660.63 (6)
1.1460.22 (4)
1.2160.37 (10) 1.0860.25 (6)
1.5760.09 (5) 1.3260.51 (27)
Suicidality Without Present
1.2160.25 (10) 1.3960.92 (3)
1.1460.34 (16) 1.1460.22 (4)
1.4160.48 (13) 1.3360.49 (19)
Healthy controls
1.2160.21 (65)
equally ( x 2 5 0.03; df 5 1; P 5 0.85) in both depressed and nondepressed veterans. In war veterans without PTSD, suicidality occurred more frequently ( x 2 5 4.63; df 5 1; P 5 0.031) in depressed veterans, while the other symptoms, like loss of appetite ( x 2 5 2.51; df 5 1; P 5 0.11), pessimistic thoughts ( x 2 5 1.78; df 5 1; P 5 0.18), inability to feel ( x 2 5 0.72; df 5 1; P 5 0.40), concentration difficulties ( x 2 5 0.35; df 5 1; P 5 0.55), and insomnia ( x 2 5 0.003; df 5 1; P 5 0.96), occurred similarly in depressed and nondepressed veterans (Table 3). There was significant difference (F 5 2.79; df 5 7,122; P , 0.01) in platelet 5-HT concentration between healthy controls and depressed and nondep-
ressed war veterans, with or without PTSD, with or without appetite loss (Table 3). When war veterans were further subdivided according to the severity of appetite loss (Fig. 2), moderate loss was found in all groups, while severe reduction in appetite was observed only in the group of depressed veterans with PTSD. Platelet 5-HT concentration was significantly different (F 5 2.20; df 5 8,121; P 5 0.03) between groups of healthy controls and war veterans with different degrees of appetite loss. The highest platelet 5-HT concentration was observed in group of depressed veterans with severe loss of appetite, as compared (P , 0.05, Tukey) to the values in controls and depressed veterans with PTSD, but without appetite loss (Fig. 2). There was a small but signifi-
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Fig. 2. Platelet 5-HT concentration in controls and in war veterans with or without PTSD/ depression and different severity of appetite loss. Bars represent mean6S.D. with number of patients in parentheses. a P , 0.05 vs. control subjects and depressed PTSD without appetite loss (ANOVA and Tukey test).
cant positive correlation (r 5 0.36; P 5 0.04) between platelet 5-HT and different degrees of appetite loss in war veterans with PTSD. Platelet 5-HT concentration did not differ in groups of war veterans with or without other depressive symptoms like insomnia (F 5 1.52; df 5 5,124; P 5 0.19), concentration difficulties (F 5 1.53; df 5 5,124; P 5 0.19), inability to feel (F 5 1.58; df 5 7,122; P 5 0.15), pessimistic thoughts (F 5 1.67; df 5 7,122; P 5 0.12), and suicidality (F 5 1.36; df 5 6,123; P 5 0.24) (Table 3).
4. Discussion In the present study we have found that war veterans with PTSD were more vulnerable to develop depression than those without PTSD. The comorbid depression appeared in one-half of war veterans with PTSD and in one third of war veterans without PTSD in subjects who were devoid of any psychiatric disorder prior to trauma events. Although comorbidity patterns might be geographically and culturally specific (Spivak et al., 2000), our data are in agreement with the finding of the high prevalence of depression in PTSD subjects (Kaufman and Charney, 2000; Shalev, 2000) and US National
Comorbidity survey (Shalev, 2000). In addition, depressed veterans with PTSD had more avoidance and numbing symptoms than nondepressed PTSD veterans, suggesting that coexisting depression worsened PTSD symptoms. In the present study we have determined platelet 5-HT concentration in a large number of war veterans and matched healthy controls. Our results of similar 5-HT concentration between groups are in line with the previously published data (Mellman ˇ ˇ ˇ and Kumar, 1994; Cicin-Sain et al., 2000), although previous studies lacked the corresponding control group of war veterans who did not develop PTSD. Although dysregulation of serotonergic system is assumed to be related to depression (Meltzer, 1989; Maes and Meltzer, 1995), we have previously found an unaltered platelet 5-HT concentration in depressed ¨ ˇ patients (Muck-Seler et al., 1991, 1996a; Pivac et al., 1997a; Jakovljevic´ et al., 1997), and in the present study we have shown no alterations in platelet 5-HT concentration in war veterans with or without comorbid depression. In support of our findings, no differˇ ˇ ˇ ence was reported in platelet 5-HT levels (Cicin-Sain ˇ ˇ ˇ et al., 2000) and platelet 5-HT uptake (Cicin-Sain et al., 2000) in PTSD subjects with different psychiatric comorbidity, or in platelet 3 H-paroxetine binding in depressed or nondepressed combat veterans (Arora et al., 1993; Maguire et al., 1998). This work, to our knowledge, represents the first detail evaluation of the relationship between different depressive symptoms and platelet 5-HT concentration in war veterans with or without PTSD. The most prominent change in platelet 5-HT concentration was observed in the groups of war veterans with PTSD and with different degrees of appetite loss, while there was no association between platelet 5-HT concentrations and other depressive symptoms. A positive relationship was found between alterations in appetite and platelet 5-HT concentration. We have shown that the most pronounced loss of appetite was associated with the highest platelet 5-HT concentrations. These data support the findings that 5-HT has a suppressive effect on food intake in animals (Simansky, 1995) and in humans (Leibowitz and Alexander, 1998). Increased platelet 5-HT concentration in subjects with severe appetite loss might be a consequence of increased platelet 5-HT uptake. Although in the
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present study we did not determine platelet 5-HT uptake, the majority of the previous studies using 14 ˇ ˇ ˇ C-5-HT (Mellman and Kumar, 1994; Cicin-Sain et al., 2000), or platelet 3 H-paroxetine (Maguire et al., 1998) and 3 H-imipramine (Weizman et al., 1996) binding, did not find altered 5-HT uptake in platelets of subjects with PTSD. On the other hand, a low number of 5-HT uptake sites, determined by 3 Hparoxetine binding, was reported in blood platelets of PTSD subjects (Arora et al., 1993; Fichtner et al., 1995), and Maes et al. (1999) showed decreased affinity of platelet 3 H-paroxetine binding sites in PTSD subjects that was irrespective of the presence of major depression. Altered platelet 5-HT in war veterans with PTSD, with various degrees of appetite loss, might be caused by a disturbance in the synthesis and catabolism of 5-HT. Platelet 5-HT is derived from the enterochromaffine cells of the gut, as platelets lack enzymes for 5-HT synthesis. Plasma concentration of the 5-HT precursor, tryptophan, plays an important role in 5-HT synthesis (Nishizawa et al., 1997), and reduced plasma tryptophan availability could be involved in the pathophysiology of depression (Meltzer, 1989). However, unaltered plasma concentrations of tryptophan or other large neutral amino acids, except tyrosine, was recently found in PTSD (Maes et al., 1999), suggesting that 5-HT synthesis is not altered. Regarding the catabolism of 5-HT, decreased ˇ ˇ platelet MAO-B activity in PTSD subjects (Cicinˇ ´ ˇ ´ et al., 2000) and Sain et al., 2000; Kozaric-Kovacic in PTSD with comorbid alcoholism (Davidson et al., 1985) was described. However, the significance of platelet MAO-B in the metabolism of platelet 5-HT is not clear, since this type of MAO metabolizes 5-HT very poorly (Dostert et al., 1989), and we failed to find any relationship between platelet 5-HT concentration and platelet MAO activity in healthy ¨ ˇ controls and schizophrenic patients (Muck-Seler et al., 1991). Several other factors like gender, age, previous treatment, and seasonality, might affect platelet 5-HT concentration. In the present study only male subjects were included, and, therefore, the influence of gender on platelet 5-HT, previously observed among ¨ ˇ healthy persons (Oxenkrug, 1979; Muck-Seler et al., ¨ 1996a, 1999), depressed (Oxenkrug, 1979; Muck-
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ˇ ¨ ˇ Seler et al., 1996a), and schizophrenic (Muck-Seler et al., 1999) patients might be excluded. In addition, the influence of previous treatment could also be neglected, since all subjects were drug-free. Although no seasonal effect on platelet 5-HT concentration (Jakovljevic´ et al., 1997), or 3 H-paroxetine binding (Maguire et al., 1998) was observed, platelet 5-HT concentration in PTSD and controls subjects was determined within the same season. In agreement with the already published data that platelet 5-HT concentration is stable with ageing ¨ ˇ (Muck-Seler et al., 1996b; Franke et al., 2000), we have found no correlation between age and platelet 5-HT concentration in war veterans and control subjects. ¨ ˇ In contrast to our previous studies (Muck-Seler et al., 1996a; Pivac et al., 1997a), that showed decreased platelet 5-HT concentration in depressed patients with the most pronounced suicidal behaviour, the present study failed to detect significant differences in war veterans subdivided by the presence of suicidal symptoms, presumably due to the small number of war veterans in particular subgroups. In addition, some of them were included in the ongoing double-blind, multicentric study, that required nonsuicidal behaviour as one of the criteria for the participation. We have already suggested that platelet 5-HT concentration might be used as one of the peripheral ¨ ˇ markers for the subtypes of depression (Muck-Seler et al., 1996a; Jakovljevic´ et al., 1997; Pivac et al., 1997a), and schizophrenia (Jakovljevic´ et al., 1997; Pivac et al., 1997b). In war veterans with PTSD, a negative correlation was detected between state and trait anxiety and platelet 3 H-paroxetine binding (Fichtner et al., 1995), as well as between plasma 5-HT concentrations and HAS scores (Spivak et al., 1999). In the present study we found a significant positive correlation between platelet 5-HT concentration and severity of appetite loss in PTSD subjects, suggesting that this particular depressive symptom in PTSD might be associated with alterations in 5-HT system. On the other hand, no correlation was demonstrated between peripheral 5-HT measures and severity of PTSD symptoms evaluated by CAPS and DTS (present work), or Mississippi Scale for Combat-related PTSD and HAS (Mellman and Kumar, 1994), or between platelet MAO activity and ego
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´ ˇ ´ et strength / neuroticism in PTSD (Kozaric-Kovacic al., 2000). Since there is no direct evidence that changes in peripheral markers correlate with changes in central nervous system, further investigations are necessary to elucidate the significance of peripheral 5-HT markers and comorbid diseases in PTSD. In conclusion, we have found a high incidence of comorbid depression among war veterans with PTSD. Platelet 5-HT concentration was unchanged in a large number of war veterans independent of the presence of PTSD and depression. The change in platelet 5-HT concentration was observed among war veterans with various degrees of appetite loss. In veterans with PTSD, platelet 5-HT content correlated with severity of appetite loss. Platelet 5-HT concentration was not associated with severity of other symptoms of PTSD or depression. Our data suggest that 5-HT system is involved in the regulation of appetite, at least in depressed war veterans with PTSD.
Acknowledgements Thanks are due to the staff of University Psychiatric Clinic, Clinical Hospital Centre Zagreb, and to ˇ ´ for her technical assistance. Mrs Zlatica Tonsetic This study was supported by the Croatian Ministry of Science.
References Andres, A.H., Rao, M.A., Ostrowitzki, S., Enzian, W., 1993. Human brain cortex and platelet serotonin 2 receptor binding properties and their regulation by endogenous serotonin. Life Sci. 52, 313–321. American Psychiatric Association, 1994. Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, American Psychiatric Press, Washington, DC. Arora, R.C., Fichtner, C.G., O’Connor, F., Crayton, J.W., 1993. Paroxetine binding in the blood platelets of posttraumatic stress disorder patients. Life Sci. 53, 919–928. Charney, D.S., Deutch, A.Y., Krystal, J.H., Southwick, S.M., Davis, M., 1993. Psychobiologic mechanism of posttraumatic stress disorder. Arch. Gen. Psychiatry 50, 294–305. ˇ ˇ ˇ ´ D., Balija, M., Ljubin, T., Cicin-Sain, L., Mimica, N., Hranilovic, ´ G., Folnegovic-Smalc, ´ ˇ Makaric, V., Jernej, B., 2000. Posttraumatic stress disorder and platelet serotonin measures. J. Psychiatric Res. 34, 155–161.
Davidson, J., Lipper, S., Kilts, C.D., Mahorney, S., Hammett, E., 1985. Platelet MAO activity in posttraumatic stress disorder. Am. J. Psychiatry 142, 1341–1343. Davis, L.L., Sarias, A., Lambert, M.T., Heimberg, C., Petty, F., 1997. Posttraumatic stress disorder and serotonin—new direction for research and treatment. J. Psychiatry Neurosci. 22, 318–320. Dostert, P.L., Strolin-Benedetti, M., Tipton, K.F., 1989. Interactions of monoamine oxidase with substrates and inhibitors. Medicinal Res. Rev. 9, 45–89. Fichtner, C.G., O’Connor, F.L., Yeoh, H.C., Arora, R.A., Crayton, J.W., 1995. Hypodensity of platelet serotonin uptake sites in posttraumatic stress disorder: associated clinical features. Life Sci. 57, 37–44. ¨ Franke, L., Schewe, H.-J., Muller, B., Campman, V., Kitzrow, W., Uebelhack, R., Berghofer, A., Muller-Oerlinghausen, B., 2000. Serotonergic platelet variables in unmedicated patients suffering from major depression and healthy subjects. Relationship between 5-HT content and 5-HT uptake. Life Sci. 67, 301–315. ´ M., 1998. Neurobiology of psychotraumatic exJakovljevic, perience: Is PTSD really an unique psychopathological and diagnostic entity? Psychiatria Danubina 10, 75–78. ´ M., Muck-Seler, ¨ ˇ ˇ ´ D« ., Bujas, Jakovljevic, D., Pivac, N., Ljubicic, M., Dodig, G., 1997. Seasonal influence on platelet 5-HT levels in patients with recurrent major depression and schizophrenia. Biol. Psychiatry 41, 1028–1034. Kaufman, J., Charney, D., 2000. Comorbidity of mood and anxiety disorders. Depression and Anxiety 12 (Suppl. 1), 69– 76. ´ ˇ ´ D., Ljubin, T., Rutic-Puz, ´ ˇ L., Mihaljevic, ´ J., Kozaric-Kovacic, ˇ ˇ ˇ Jernej, B., Cicin-Sain, L., 2000. Platelet monoamine oxidase activity, ego strength, and neuroticism in soldiers with combat related current posttraumatic stress disorder. Croatian Med. J. 41, 76–80. Leibowitz, S.F., Alexander, J.T., 1998. Hypothalamic serotonin in control of eating behavior, meal size, and body weight. Biol. Psychiatry 44, 851–864. Lowry, O.H., Rosenbrough, N.S., Farr, A.C., Randall, R.J., 1951. Protein measurement with the Folin phenol reagent. J. Biol. Chem. 193, 265–275. Maes, M., Meltzer, H.Y., 1995. The serotonin hypothesis of major depression. In: Bloom, F.E., Kupfer, D.J. (Eds.), Psychopharmacology: The Fourth Generation of Progress. Raven Press, New York, pp. 933–944, Chapter 81. Maes, M., Lin, A.-H., Verkerk, R., Delmeire, L., Van Gastel, A., Van der Planken, M., Scharpe, S., 1999. Serotonergic and noradrenergic markers of post-traumatic stress disorder with and without major depression. Neuropsychopharmacology 20, 188–197. Maguire, K., Norman, T., Burrows, G., Hopwood, M., Morris, P., 1998. Platelet paroxetine binding in post-traumatic stress disorder. Psychiatry Res. 77, 1–7. Mellman, T.A., Kumar, A.M., 1994. Platelet serotonin measures in posttraumatic stress disorder. Psychiatry Res. 53, 99–101. Meltzer, H., 1989. Serotonergic dysfunction in depression. Br. J. Psychiatry 155 (Suppl. 8), 25–31. ˇ 1988. Time course ¨ ˇ ´ M., Deanovic, ´ Z., Muck-Seler, D., Jakovljevic,
¨ ˇ et al. / Journal of Affective Disorders 75 (2003) 171–179 D. Muck-Seler of schizophrenia and platelet 5-HT level. Biol. Psychiatry 23, 243–251. ˇ 1991. Platelet ¨ ˇ ´ M., Deanovic, ´ Z., Muck-Seler, D., Jakovljevic, serotonin in subtypes of schizophrenia and unipolar depression. Psychiatry Res. 38, 105–113. ¨ ˇ ´ M., Pivac, N., 1996a. Platelet 5-HT Muck-Seler, D., Jakovljevic, concentrations and suicidal behavior in recurrent major depression. J. Affect. Disord. 39, 73–80. ¨ ˇ ´ ´ M., Muck-Seler, D., Bujas, M., Ljubic-Thibal, V., Jakovljevic, 1996b. Effects of age on platelet 5-HT concentrations in healthy controls, depressed and schizophrenic patients. Neuropsychobiology 34, 201–203. ¨ ˇ ´ M., 1999. Sex differences, Muck-Seler, D., Pivac, N., Jakovljevic, season of birth and platelet 5-HT levels in schizophrenic patients. J. Neural Transm. 106, 337–347. Nishizawa, S., Benkelfat, C., Young, S.N., Leyton, M., Mzengeza, S., de Montigny, C., Blier, P., Diksic, M., 1997. Differences between males and females in rates of serotonin synthesis in human brain. Proc. Natl. Acad. Sci. USA 94, 5308–5313. Oxenkrug, G.F., 1979. The content and uptake of 5-HT by blood platelets in depressive patients. J. Neural Transm. 45, 285–289. ´ M., Muck-Seler, ¨ ˇ ´ Z., 1997a. Pivac, N., Jakovljevic, D., Brzovic, Hypothalamic–pituitary–adrenal axis function and platelet serotonin concentrations in depressed patients. Psychiatry Res. 73, 123–132. ¨ ˇ ´ M., 1997b. Platelet 5-HT Pivac, N., Muck-Seler, D., Jakovljevic, levels and hypothalamic–pituitary–adrenal axis in schizophrenic patients with positive and negative symptoms. Neuropsychobiology 36, 19–21. Shalev, A.Y., 2000. Posttraumatic stress disorder: diagnosis, history and life course. In: Nutt, D., Davidson, J.R.T., Zohar, J. (Eds.), Posttraumatic Stress Disorder: Diagnosis, Management and Treatment. Martin Dunitz, London, pp. 1–15.
179
Simansky, K.J., 1995. Serotoninergic control of the organization of feeding and satiety. Behav. Brain Res. 73, 37–42. Southwick, S.M., Krystal, J.H., Morgan, A., Johnson, D., Nagy, L., Nicolaou, A., Heninger, G.R., Charney, D.S., 1993. Abnormal noradrenergic function in posttraumatic stress disorder. Arch. Gen. Psychiatry 50, 266–274. Spivak, B., Vered, Y., Graff, E., Blum, I., Mester, R., Weizman, A., 1999. Low platelet poor plasma concentrations of serotonin in patients with combat-related posttraumatic stress disorder. Biol. Psychiatry 45, 840–845. Spivak, B., Segal, M., Laufer, N., Mester, R., Weizman, A., 2000. Lifetime psychiatric comorbidity rate in Israeli non-help-seeking patients with combat-related post-traumatic stress disorder. J. Affect. Disord. 57, 185–188. Stahl, S.M., 1985. Platelets as pharmacological models for the receptors and biochemistry of monoaminergic neurons. In: Longenecker, G.L. (Ed.), Platelets: Physiology and Pharmacology. Academic Press, New York, pp. 307–340. Stahl, S.M., 1998. Mechanism of action of serotonin selective reuptake inhibitors. Serotonin receptors and pathways mediate therapeutic effects and side effects. J. Affect. Disord. 51, 215–235. Weizman, R., Laor, N., Schujovitsky, A., Wolmer, L., Abramovitz-Schnaider, P., Freudstein-Dan, A., Rehavi, M., 1996. Platelet imipramine binding in patients with posttraumatic stress disorder before and after phenelzine treatment. Psychiatry Res. 63, 143–150. Yehuda, R., 2000. Neuroendocrinology. In: Nutt, D., Davidson, J.R.T., Zohar, J. (Eds.), Posttraumatic Stress Disorder: Diagnosis, Management and Treatment. Martin Dunitz, London, pp. 53–67.
Research report
Platelet 5-HT concentration and comorbid depression in war veterans with and without posttraumatic stress disorder a, b ˇ *, Nela Pivac a , Miro Jakovljevic´ b , Marina Sagud ¨ ˇ Dorotea Muck-Seler , ´ ˇb Alma Mihaljevic-Peles a
ˇ ´ Institute, P.O. Box 180, HR-10002 Zagreb, Croatia Laboratory for Molecular Neuropharmacology, Ru)jer Boskovic b University Psychiatric Clinic, Clinical Hospital Centre Zagreb, Zagreb, Croatia Received 30 April 2001; received in revised form 21 January 2002; accepted 22 January 2002
Abstract Background: The serotonergic system is implicated in the pathophysiology of posttraumatic stress disorder (PTSD) and depression. The present study focused on platelet serotonin (5-HT) concentration and symptoms of comorbid depression in war veterans with or without PTSD. Methods: PTSD and depression were evaluated using Clinician Administered PTSD Scale, Davidson Trauma Scale, Montgomery–Asberg Depression Rating Scale and Hamilton Anxiety Scale. Sixty-five male drug-free war veterans (48 with PTSD and 17 without PTSD) and 65 age- and sex-matched healthy controls were studied. Results: Comorbid depression occurred in 54 and 31% of war veterans with PTSD and without PTSD, respectively. Platelet 5-HT concentration was similar in the groups of depressed and nondepressed war veterans with or without PTSD and healthy controls. Platelet 5-HT concentration was found to differ between war veterans with various degrees of appetite loss. A positive correlation was observed between platelet 5-HT concentration and severity of appetite loss in veterans with PTSD. There was no relationship between platelet 5-HT concentration and severity of other symptoms of PTSD or depression. Limitations: War veterans included in the study were outpatients. Conclusions: War veterans with PTSD had a high incidence of comorbid depression, that was not related to platelet 5-HT concentration. The marked relationship between platelet 5-HT concentration and severity of appetite loss, suggested that 5-HT system is involved in the regulation of appetite, at least in depressed war veterans with PTSD. 2002 Elsevier Science B.V. All rights reserved. Keywords: Posttraumatic stress disorder; War veterans; Depression; Platelet 5-HT; Appetite loss
1. Introduction Posttraumatic stress disorder (PTSD) is an illness *Corresponding author. Tel.: 1 385-1-456-1111; fax: 1 385-1456-1010. ¨ ˇ E-mail address: [email protected] (D. Muck-Seler).
of chronic course, high morbidity and treatment resistance. Combat exposure is the most frequent cause of PTSD in men, while sexual abuse is the most frequent precipitant of PTSD in women (Kaufman and Charney, 2000). The characteristic symptoms of PTSD involve mental reliving of the trauma, numbing the responsiveness to the external stimuli,
0165-0327 / 02 / $ – see front matter 2002 Elsevier Science B.V. All rights reserved. doi:10.1016/S0165-0327(02)00035-6
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avoidance of stimuli associated with trauma, and ´ increased arousal (Charney et al., 1993; Jakovljevic, 1998; Shalev, 2000). Depressive symptoms are common features in PTSD patients, and major depression is a frequent coexisting comorbidity in ´ 1998; Shalev, 2000). PTSD (Jakovljevic, The ethiology of PTSD is not clear. PTSD has been reported to be associated with the alterations in serotonergic (Davis et al., 1997; Maes et al., 1999), noradrenergic (Southwick et al., 1993; Maes et al., 1999), dopaminergic, opiate, CRH (Charney et al., 1993) systems and in altered activity of hypothalamic–pituitary–adrenal axis (Yehuda, 2000). Previous investigations of serotonergic function in war veterans with PTSD studied blood platelet serotonin (5-HT, 5-hydroxytryptamine) as a peripheral model for the central serotonergic neurones (Stahl, 1985; Andres et al., 1993). Unaltered platelet 5-HT uptake and 5-HT concentrations (Melˇ ˇ ˇ lman and Kumar, 1994; Cicin-Sain et al., 2000), decreased platelet monoamine oxidase (MAO) ac-
ˇ ˇ ˇ tivity (Davidson et al., 1985; Cicin-Sain et al., 2000), and reduced (Arora et al., 1993), increased (Maes et al., 1999), or unaltered (Maguire et al., 1998) 3 Hparoxetine binding to platelet membranes have been found in PTSD. Although 5-HT regulates a myriad of physiological and pathological functions (see Stahl, 1998), that could be disturbed in PTSD, there were no data about the relationship between blood platelet 5-HT and different symptoms of PTSD and comorbid depression. The aim of the present study was to elucidate the role of the serotonergic system in PTSD with comorbid depression. In this respect, we determined: (a) frequency of the occurrence of comorbid depression in male war veterans with or without PTSD; (b) correlation between different clinical scales for PTSD and depression and platelet 5-HT concentration; and (c) platelet 5-HT concentrations in war veterans with or without PTSD, subdivided by the presence of comorbid depression, and different depressive symptoms (concentration difficulties, loss of
Table 1 CAPS, DTS, MADRS and HAS scores in war veterans with or without PTSD subdivided according to the presence or absence of comorbid depression Scales
Scores (mean6S.D.) War veterans Without PTSD (17)
With PTSD (48)
Nondepressed (13)
Depressed (4)
Nondepressed (16)
Depressed (32)
CAPS Total B C D E (years)
32.3615.0 9.865.6 13.067.4 8.765.7 2.660.8
42.363.8 11.863.0 17.862.8 15.364.2 2.360.5
62.9610.5 a 18.664.6 a 22.665.0 a 20.664.3 a 4.862.0 a
66.1612.0 a 20.065.2 a 26.364.6 a 19.465.2 4.061.9
DTS Total Frequency Severity
22.0613.3 9.265.4 12.968.1
31.861.5 13.561.3 18.360.5
46.8610.8 b 21.865.8 c 25.066.1 d
51.7617.6 b 24.1612.2 29.369.8 d
7.965.7 9.565.3
17.061.6 18.061.8
11.063.3 13.366.0
19.963.9 17.266.3
MADRS HAS
B, reexperiencing symptoms; C, avoidance and numbing symptoms; D, hyperarousal symptoms; E, duration of disturbance. a P , 0.05 vs. the corresponding war veterans without PTSD (ANOVA and Tukey test). b P , 0.05 vs. the corresponding groups of war veterans without PTSD (ANOVA and Tukey test). c P , 0.05 vs. nondepressed subjects without PTSD (ANOVA and Tukey test). d P , 0.05 vs. the corresponding groups of war veterans without PTSD (ANOVA and Tukey test).
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appetite, inability to feel, insomnia, pessimistic thoughts, and suicidality), and in age- and sexmatched healthy controls.
2. Methods
2.1. Subjects The study included 65 Croatian male war veterans and 65 age-matched healthy male subjects (control subjects). The mean6S.D. age in the group of war veterans was 32.867.8 years (range 22–50 years), and in control subjects 31.468.1 years (range 20–56 years). After structured clinical interview, based on the DSM-IV criteria (American Psychiatric Association, 1994), performed by the experienced psychiatˇ ´ M. Sagud, ´ rists (M. Jakovljevic, A. Mihaljevicˇ war veterans were divided into two groups Peles), according to the Clinician Administered PTSD Scale (CAPS) in (a) 48 subjects with current chronic PTSD (CAPS scores . 50) and (b) 17 subjects without current PTSD (CAPS scores , 50). The frequency and severity of PTSD symptoms and anxiety were evaluated using Davidson Trauma Scale (DTS) and Hamilton Anxiety Scale (HAS), respectively. According to the Montgomery–Asberg Depression Rating Scale (MADRS), war veterans were further subdivided into groups with depression (total scores 5 15) and without depression (total scores , 15). The mean scores in particular scales for PTSD and depression are shown in Table 1. Depressive symptoms (loss of appetite, insomnia, inability to feel, concentration difficulties, suicidality, and pessimistic thoughts) were evaluated using MADRS, and war veterans were subdivided into two groups: without symptoms (score 0), or present symptoms (that included moderate, severe, and very severe symptoms). The different degrees of symptoms of appetite loss were subdivided into: (a) symptoms not present (score 0); (b) moderate (scores 1–2); and (c) severe (scores 3–4) symptoms. War veterans were outpatients, and some of them were included in an ongoing double-blind, multicentric study. Subjects who had suffered from major depression or other axis-I diagnosis before combat experience were excluded. None of the subjects had a secondary diagnosis of alcoholism or drug depen-
173
dency. Nonpsychiatric medical comorbidity at the time of the survey was assessed by the response to interviewer questions. Headaches (18 subjects), back pains (seven subjects) and gastro-intestinal symptoms (five subjects) were the predominant somatic problems. Subjects with PTSD were drug-free for at least 2 weeks before sampling. Control subjects were mainly medical stuff, with no personal or family history of psychopathology, and no medical treatment. All participants gave their written consent.
2.2. Biochemical analysis Blood (4 ml) was drawn from cubical vein at 08:00 h in a plastic syringe with 1 ml of acid citrate dextrose anticoagulant. Platelet-rich-plasma (PRP) was obtained by centrifugation (935 3 g) for 70 s at room temperature. Platelets were sedimented by further centrifugation of PRP at 10 000 3 g for 5 min. The platelet pellet was washed with saline and centrifuged again. Platelet 5-HT concentrations were determined by ¨ ˇ the spectrofluorimetric method (Muck-Seler et al., 1988). Briefly, platelets were destroyed by sonication (20 kHz, amplitude 8 3 10 23 mm for 30 s). Specimens of standard, blank (water) and platelet sonicates were analysed in duplicate. All samples were deproteinized with 1 ml of 10% ZnSO 4 and 0.5 ml of 1 N NaOH. For the preparation of fluorophore, 0.2 ml of L-cysteine (0.1%) and 1.0 ml of orthophthalaldehyde (0.05%) were added to deproteinized samples. The measurement of the 5-HT fluorescence was performed on an Aminco-Bowman spectrofluorimeter. Platelet protein was determined by the method of Lowry et al. (1951).
2.3. Statistical analysis All results were expressed as mean6S.D. The differences between groups were assessed by oneway analysis of variance (ANOVA), followed by Tukey multiple comparison procedure. Student’s ttest was used when only two groups were compared. The correlation between platelet 5-HT and age, different clinical scales, or various degrees of depressive symptoms, was determined by Pearson’s coefficient of correlation. The frequency of the occurrence of depressive symptoms was determined by a x 2 test.
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3. Results The comorbid depression appeared in 54% of war veterans with PTSD and in 31% of veterans without PTSD (Fig. 1), with a greater frequency of depression ( x 2 5 7.79; df 5 1, P , 0.005) in veterans with PTSD. Table 1 shows different clinical scales for PTSD and depression in war veterans. Depressed veterans with PTSD had significantly higher scores (F 5 20.59; df 5 3,64; P , 0.001) of avoidance and numbing symptoms (CAPS subscale C) than nondepressed PTSD veterans (Table 1). One-way ANOVAs revealed significant differences in total scores in DTS (F 5 13.45; df 5 3,61; P , 0.001) and in subscales of trauma frequency (F 5 8.47; df 5 3,61; P , 0.001) and severity (F 5 12.65; df 5 3,61; P , 0.001). War veterans with PTSD had significantly higher (P , 0.05, Tukey) scores in total and both subscales of DTS, as compared to corresponding groups of war veterans without PTSD (Table 1). War veterans (1.2960.43 nmol / mg protein) and healthy controls (1.2160.21 nmol / mg protein) had similar (t 5 1.06; df 5 128; P 5 0.21, Student’s t-
test) platelet 5-HT concentration. There was no difference in platelet 5-HT concentration (F 5 0.77; df 5 2,127; P 5 0.46) between groups of war veterans with PTSD (1.2960.45 nmol / mg protein), without PTSD (1.2860.40 nmol / mg protein), and control subjects. Fig. 1 shows lack of significant difference (F 5 1.91; df 5 4,125; P 5 0.11) in platelet 5-HT concentration between healthy controls and war veterans with and without PTSD, subdivided further by the presence or absence of comorbid depression. There was no correlation between platelet 5-HT concentration and scores in clinical scales (Table 2). Platelet 5-HT concentration was not associated with age in war veterans (r 5 0.15; P 5 0.40) or in control subjects (r 5 2 0.07; P 5 0.71). In war veterans with PTSD, symptoms of pessimistic thoughts ( x 2 5 8.84, df 5 1; P 5 0.003), suicidality ( x 2 5 13.34; df 5 1; P 5 0.001), and loss of appetite ( x 2 5 3.77; df 5 1; P 5 0.05), occurred more frequently in depressed than in nondepressed veterans (Table 3). All veterans with PTSD had the symptoms of concentration difficulties and insomnia, while symptom of inability to feel was present
Table 2 The Pearson’s coefficient of correlation (r) between platelet 5-HT concentration and clinician administered PTSD scale (CAPS), DTS, MADRS and HAS scores in war veterans with or without PTSD Scales
Platelet 5-HT (nmol / mg protein) War veterans Without (17)
CAPS Total B C D E (years)
Fig. 1. Individual platelet 5-HT concentrations in controls and in war veterans with or without PTSD and comorbid depression. The mean value in each group is indicated by a horizontal line drawn through the corresponding data points.
DTS Total Frequency Severity MADRS HAS
PTSD With PTSD (48)
r
p
r
p
0.02 0.12 0.28 2 0.20 0.36
0.95 0.65 0.28 0.44 0.16
2 0.07 0.10 0.18 2 0.02 0.07
0.64 0.49 0.24 0.91 0.64
0.01 0.01 0.01
0.98 0.99 0.97
0.08 0.11 0.03
0.61 0.45 0.87
0.18 2 0.21
0.43 0.41
0.27 0.24
0.07 0.10
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Table 3 Platelet 5-HT (mean6S.D.) in healthy controls and in war veterans with or without PTSD (with or without depression) subdivided according to the presence or absence of depressive symptoms War veterans Platelet 5-HT (nmol / mg protein) Without PTSD (17)
With PTSD (48)
Nondepressed (13)
Depressed (4)
Nondepressed (16)
Depressed (32)
Symptoms Appetite loss Without Present
1.5060.31 (9) 1.0660.51 (4)
1.1460.22 (4)
1.0760.26 (12) 1.3560.49 (4)
1.2460.50 (13) 1.4560.46 (19)
Insomnia Without Present
1.3260.33 (2) 1.3360.48 (11)
1.1460.22 (4)
1.1460.34 (16)
1.3760.48 (32)
Inability to feel Not present Present
1.3460.22 (5) 1.3360.55 (8)
1.1460.22 (4)
0.9760.06 (2) 1.1660.34 (14)
0.9960.64 (2) 1.3960.47 (30)
Concentration difficulties Without Present
1.3360.25 (4) 1.3360.51 (9)
1.1460.22 (4)
1.1460.34 (16)
1.3760.48 (32)
Pessimistic thoughts Without Present
1.3960.21 (7) 1.2660.63 (6)
1.1460.22 (4)
1.2160.37 (10) 1.0860.25 (6)
1.5760.09 (5) 1.3260.51 (27)
Suicidality Without Present
1.2160.25 (10) 1.3960.92 (3)
1.1460.34 (16) 1.1460.22 (4)
1.4160.48 (13) 1.3360.49 (19)
Healthy controls
1.2160.21 (65)
equally ( x 2 5 0.03; df 5 1; P 5 0.85) in both depressed and nondepressed veterans. In war veterans without PTSD, suicidality occurred more frequently ( x 2 5 4.63; df 5 1; P 5 0.031) in depressed veterans, while the other symptoms, like loss of appetite ( x 2 5 2.51; df 5 1; P 5 0.11), pessimistic thoughts ( x 2 5 1.78; df 5 1; P 5 0.18), inability to feel ( x 2 5 0.72; df 5 1; P 5 0.40), concentration difficulties ( x 2 5 0.35; df 5 1; P 5 0.55), and insomnia ( x 2 5 0.003; df 5 1; P 5 0.96), occurred similarly in depressed and nondepressed veterans (Table 3). There was significant difference (F 5 2.79; df 5 7,122; P , 0.01) in platelet 5-HT concentration between healthy controls and depressed and nondep-
ressed war veterans, with or without PTSD, with or without appetite loss (Table 3). When war veterans were further subdivided according to the severity of appetite loss (Fig. 2), moderate loss was found in all groups, while severe reduction in appetite was observed only in the group of depressed veterans with PTSD. Platelet 5-HT concentration was significantly different (F 5 2.20; df 5 8,121; P 5 0.03) between groups of healthy controls and war veterans with different degrees of appetite loss. The highest platelet 5-HT concentration was observed in group of depressed veterans with severe loss of appetite, as compared (P , 0.05, Tukey) to the values in controls and depressed veterans with PTSD, but without appetite loss (Fig. 2). There was a small but signifi-
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Fig. 2. Platelet 5-HT concentration in controls and in war veterans with or without PTSD/ depression and different severity of appetite loss. Bars represent mean6S.D. with number of patients in parentheses. a P , 0.05 vs. control subjects and depressed PTSD without appetite loss (ANOVA and Tukey test).
cant positive correlation (r 5 0.36; P 5 0.04) between platelet 5-HT and different degrees of appetite loss in war veterans with PTSD. Platelet 5-HT concentration did not differ in groups of war veterans with or without other depressive symptoms like insomnia (F 5 1.52; df 5 5,124; P 5 0.19), concentration difficulties (F 5 1.53; df 5 5,124; P 5 0.19), inability to feel (F 5 1.58; df 5 7,122; P 5 0.15), pessimistic thoughts (F 5 1.67; df 5 7,122; P 5 0.12), and suicidality (F 5 1.36; df 5 6,123; P 5 0.24) (Table 3).
4. Discussion In the present study we have found that war veterans with PTSD were more vulnerable to develop depression than those without PTSD. The comorbid depression appeared in one-half of war veterans with PTSD and in one third of war veterans without PTSD in subjects who were devoid of any psychiatric disorder prior to trauma events. Although comorbidity patterns might be geographically and culturally specific (Spivak et al., 2000), our data are in agreement with the finding of the high prevalence of depression in PTSD subjects (Kaufman and Charney, 2000; Shalev, 2000) and US National
Comorbidity survey (Shalev, 2000). In addition, depressed veterans with PTSD had more avoidance and numbing symptoms than nondepressed PTSD veterans, suggesting that coexisting depression worsened PTSD symptoms. In the present study we have determined platelet 5-HT concentration in a large number of war veterans and matched healthy controls. Our results of similar 5-HT concentration between groups are in line with the previously published data (Mellman ˇ ˇ ˇ and Kumar, 1994; Cicin-Sain et al., 2000), although previous studies lacked the corresponding control group of war veterans who did not develop PTSD. Although dysregulation of serotonergic system is assumed to be related to depression (Meltzer, 1989; Maes and Meltzer, 1995), we have previously found an unaltered platelet 5-HT concentration in depressed ¨ ˇ patients (Muck-Seler et al., 1991, 1996a; Pivac et al., 1997a; Jakovljevic´ et al., 1997), and in the present study we have shown no alterations in platelet 5-HT concentration in war veterans with or without comorbid depression. In support of our findings, no differˇ ˇ ˇ ence was reported in platelet 5-HT levels (Cicin-Sain ˇ ˇ ˇ et al., 2000) and platelet 5-HT uptake (Cicin-Sain et al., 2000) in PTSD subjects with different psychiatric comorbidity, or in platelet 3 H-paroxetine binding in depressed or nondepressed combat veterans (Arora et al., 1993; Maguire et al., 1998). This work, to our knowledge, represents the first detail evaluation of the relationship between different depressive symptoms and platelet 5-HT concentration in war veterans with or without PTSD. The most prominent change in platelet 5-HT concentration was observed in the groups of war veterans with PTSD and with different degrees of appetite loss, while there was no association between platelet 5-HT concentrations and other depressive symptoms. A positive relationship was found between alterations in appetite and platelet 5-HT concentration. We have shown that the most pronounced loss of appetite was associated with the highest platelet 5-HT concentrations. These data support the findings that 5-HT has a suppressive effect on food intake in animals (Simansky, 1995) and in humans (Leibowitz and Alexander, 1998). Increased platelet 5-HT concentration in subjects with severe appetite loss might be a consequence of increased platelet 5-HT uptake. Although in the
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present study we did not determine platelet 5-HT uptake, the majority of the previous studies using 14 ˇ ˇ ˇ C-5-HT (Mellman and Kumar, 1994; Cicin-Sain et al., 2000), or platelet 3 H-paroxetine (Maguire et al., 1998) and 3 H-imipramine (Weizman et al., 1996) binding, did not find altered 5-HT uptake in platelets of subjects with PTSD. On the other hand, a low number of 5-HT uptake sites, determined by 3 Hparoxetine binding, was reported in blood platelets of PTSD subjects (Arora et al., 1993; Fichtner et al., 1995), and Maes et al. (1999) showed decreased affinity of platelet 3 H-paroxetine binding sites in PTSD subjects that was irrespective of the presence of major depression. Altered platelet 5-HT in war veterans with PTSD, with various degrees of appetite loss, might be caused by a disturbance in the synthesis and catabolism of 5-HT. Platelet 5-HT is derived from the enterochromaffine cells of the gut, as platelets lack enzymes for 5-HT synthesis. Plasma concentration of the 5-HT precursor, tryptophan, plays an important role in 5-HT synthesis (Nishizawa et al., 1997), and reduced plasma tryptophan availability could be involved in the pathophysiology of depression (Meltzer, 1989). However, unaltered plasma concentrations of tryptophan or other large neutral amino acids, except tyrosine, was recently found in PTSD (Maes et al., 1999), suggesting that 5-HT synthesis is not altered. Regarding the catabolism of 5-HT, decreased ˇ ˇ platelet MAO-B activity in PTSD subjects (Cicinˇ ´ ˇ ´ et al., 2000) and Sain et al., 2000; Kozaric-Kovacic in PTSD with comorbid alcoholism (Davidson et al., 1985) was described. However, the significance of platelet MAO-B in the metabolism of platelet 5-HT is not clear, since this type of MAO metabolizes 5-HT very poorly (Dostert et al., 1989), and we failed to find any relationship between platelet 5-HT concentration and platelet MAO activity in healthy ¨ ˇ controls and schizophrenic patients (Muck-Seler et al., 1991). Several other factors like gender, age, previous treatment, and seasonality, might affect platelet 5-HT concentration. In the present study only male subjects were included, and, therefore, the influence of gender on platelet 5-HT, previously observed among ¨ ˇ healthy persons (Oxenkrug, 1979; Muck-Seler et al., ¨ 1996a, 1999), depressed (Oxenkrug, 1979; Muck-
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ˇ ¨ ˇ Seler et al., 1996a), and schizophrenic (Muck-Seler et al., 1999) patients might be excluded. In addition, the influence of previous treatment could also be neglected, since all subjects were drug-free. Although no seasonal effect on platelet 5-HT concentration (Jakovljevic´ et al., 1997), or 3 H-paroxetine binding (Maguire et al., 1998) was observed, platelet 5-HT concentration in PTSD and controls subjects was determined within the same season. In agreement with the already published data that platelet 5-HT concentration is stable with ageing ¨ ˇ (Muck-Seler et al., 1996b; Franke et al., 2000), we have found no correlation between age and platelet 5-HT concentration in war veterans and control subjects. ¨ ˇ In contrast to our previous studies (Muck-Seler et al., 1996a; Pivac et al., 1997a), that showed decreased platelet 5-HT concentration in depressed patients with the most pronounced suicidal behaviour, the present study failed to detect significant differences in war veterans subdivided by the presence of suicidal symptoms, presumably due to the small number of war veterans in particular subgroups. In addition, some of them were included in the ongoing double-blind, multicentric study, that required nonsuicidal behaviour as one of the criteria for the participation. We have already suggested that platelet 5-HT concentration might be used as one of the peripheral ¨ ˇ markers for the subtypes of depression (Muck-Seler et al., 1996a; Jakovljevic´ et al., 1997; Pivac et al., 1997a), and schizophrenia (Jakovljevic´ et al., 1997; Pivac et al., 1997b). In war veterans with PTSD, a negative correlation was detected between state and trait anxiety and platelet 3 H-paroxetine binding (Fichtner et al., 1995), as well as between plasma 5-HT concentrations and HAS scores (Spivak et al., 1999). In the present study we found a significant positive correlation between platelet 5-HT concentration and severity of appetite loss in PTSD subjects, suggesting that this particular depressive symptom in PTSD might be associated with alterations in 5-HT system. On the other hand, no correlation was demonstrated between peripheral 5-HT measures and severity of PTSD symptoms evaluated by CAPS and DTS (present work), or Mississippi Scale for Combat-related PTSD and HAS (Mellman and Kumar, 1994), or between platelet MAO activity and ego
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´ ˇ ´ et strength / neuroticism in PTSD (Kozaric-Kovacic al., 2000). Since there is no direct evidence that changes in peripheral markers correlate with changes in central nervous system, further investigations are necessary to elucidate the significance of peripheral 5-HT markers and comorbid diseases in PTSD. In conclusion, we have found a high incidence of comorbid depression among war veterans with PTSD. Platelet 5-HT concentration was unchanged in a large number of war veterans independent of the presence of PTSD and depression. The change in platelet 5-HT concentration was observed among war veterans with various degrees of appetite loss. In veterans with PTSD, platelet 5-HT content correlated with severity of appetite loss. Platelet 5-HT concentration was not associated with severity of other symptoms of PTSD or depression. Our data suggest that 5-HT system is involved in the regulation of appetite, at least in depressed war veterans with PTSD.
Acknowledgements Thanks are due to the staff of University Psychiatric Clinic, Clinical Hospital Centre Zagreb, and to ˇ ´ for her technical assistance. Mrs Zlatica Tonsetic This study was supported by the Croatian Ministry of Science.
References Andres, A.H., Rao, M.A., Ostrowitzki, S., Enzian, W., 1993. Human brain cortex and platelet serotonin 2 receptor binding properties and their regulation by endogenous serotonin. Life Sci. 52, 313–321. American Psychiatric Association, 1994. Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, American Psychiatric Press, Washington, DC. Arora, R.C., Fichtner, C.G., O’Connor, F., Crayton, J.W., 1993. Paroxetine binding in the blood platelets of posttraumatic stress disorder patients. Life Sci. 53, 919–928. Charney, D.S., Deutch, A.Y., Krystal, J.H., Southwick, S.M., Davis, M., 1993. Psychobiologic mechanism of posttraumatic stress disorder. Arch. Gen. Psychiatry 50, 294–305. ˇ ˇ ˇ ´ D., Balija, M., Ljubin, T., Cicin-Sain, L., Mimica, N., Hranilovic, ´ G., Folnegovic-Smalc, ´ ˇ Makaric, V., Jernej, B., 2000. Posttraumatic stress disorder and platelet serotonin measures. J. Psychiatric Res. 34, 155–161.
Davidson, J., Lipper, S., Kilts, C.D., Mahorney, S., Hammett, E., 1985. Platelet MAO activity in posttraumatic stress disorder. Am. J. Psychiatry 142, 1341–1343. Davis, L.L., Sarias, A., Lambert, M.T., Heimberg, C., Petty, F., 1997. Posttraumatic stress disorder and serotonin—new direction for research and treatment. J. Psychiatry Neurosci. 22, 318–320. Dostert, P.L., Strolin-Benedetti, M., Tipton, K.F., 1989. Interactions of monoamine oxidase with substrates and inhibitors. Medicinal Res. Rev. 9, 45–89. Fichtner, C.G., O’Connor, F.L., Yeoh, H.C., Arora, R.A., Crayton, J.W., 1995. Hypodensity of platelet serotonin uptake sites in posttraumatic stress disorder: associated clinical features. Life Sci. 57, 37–44. ¨ Franke, L., Schewe, H.-J., Muller, B., Campman, V., Kitzrow, W., Uebelhack, R., Berghofer, A., Muller-Oerlinghausen, B., 2000. Serotonergic platelet variables in unmedicated patients suffering from major depression and healthy subjects. Relationship between 5-HT content and 5-HT uptake. Life Sci. 67, 301–315. ´ M., 1998. Neurobiology of psychotraumatic exJakovljevic, perience: Is PTSD really an unique psychopathological and diagnostic entity? Psychiatria Danubina 10, 75–78. ´ M., Muck-Seler, ¨ ˇ ˇ ´ D« ., Bujas, Jakovljevic, D., Pivac, N., Ljubicic, M., Dodig, G., 1997. Seasonal influence on platelet 5-HT levels in patients with recurrent major depression and schizophrenia. Biol. Psychiatry 41, 1028–1034. Kaufman, J., Charney, D., 2000. Comorbidity of mood and anxiety disorders. Depression and Anxiety 12 (Suppl. 1), 69– 76. ´ ˇ ´ D., Ljubin, T., Rutic-Puz, ´ ˇ L., Mihaljevic, ´ J., Kozaric-Kovacic, ˇ ˇ ˇ Jernej, B., Cicin-Sain, L., 2000. Platelet monoamine oxidase activity, ego strength, and neuroticism in soldiers with combat related current posttraumatic stress disorder. Croatian Med. J. 41, 76–80. Leibowitz, S.F., Alexander, J.T., 1998. Hypothalamic serotonin in control of eating behavior, meal size, and body weight. Biol. Psychiatry 44, 851–864. Lowry, O.H., Rosenbrough, N.S., Farr, A.C., Randall, R.J., 1951. Protein measurement with the Folin phenol reagent. J. Biol. Chem. 193, 265–275. Maes, M., Meltzer, H.Y., 1995. The serotonin hypothesis of major depression. In: Bloom, F.E., Kupfer, D.J. (Eds.), Psychopharmacology: The Fourth Generation of Progress. Raven Press, New York, pp. 933–944, Chapter 81. Maes, M., Lin, A.-H., Verkerk, R., Delmeire, L., Van Gastel, A., Van der Planken, M., Scharpe, S., 1999. Serotonergic and noradrenergic markers of post-traumatic stress disorder with and without major depression. Neuropsychopharmacology 20, 188–197. Maguire, K., Norman, T., Burrows, G., Hopwood, M., Morris, P., 1998. Platelet paroxetine binding in post-traumatic stress disorder. Psychiatry Res. 77, 1–7. Mellman, T.A., Kumar, A.M., 1994. Platelet serotonin measures in posttraumatic stress disorder. Psychiatry Res. 53, 99–101. Meltzer, H., 1989. Serotonergic dysfunction in depression. Br. J. Psychiatry 155 (Suppl. 8), 25–31. ˇ 1988. Time course ¨ ˇ ´ M., Deanovic, ´ Z., Muck-Seler, D., Jakovljevic,
¨ ˇ et al. / Journal of Affective Disorders 75 (2003) 171–179 D. Muck-Seler of schizophrenia and platelet 5-HT level. Biol. Psychiatry 23, 243–251. ˇ 1991. Platelet ¨ ˇ ´ M., Deanovic, ´ Z., Muck-Seler, D., Jakovljevic, serotonin in subtypes of schizophrenia and unipolar depression. Psychiatry Res. 38, 105–113. ¨ ˇ ´ M., Pivac, N., 1996a. Platelet 5-HT Muck-Seler, D., Jakovljevic, concentrations and suicidal behavior in recurrent major depression. J. Affect. Disord. 39, 73–80. ¨ ˇ ´ ´ M., Muck-Seler, D., Bujas, M., Ljubic-Thibal, V., Jakovljevic, 1996b. Effects of age on platelet 5-HT concentrations in healthy controls, depressed and schizophrenic patients. Neuropsychobiology 34, 201–203. ¨ ˇ ´ M., 1999. Sex differences, Muck-Seler, D., Pivac, N., Jakovljevic, season of birth and platelet 5-HT levels in schizophrenic patients. J. Neural Transm. 106, 337–347. Nishizawa, S., Benkelfat, C., Young, S.N., Leyton, M., Mzengeza, S., de Montigny, C., Blier, P., Diksic, M., 1997. Differences between males and females in rates of serotonin synthesis in human brain. Proc. Natl. Acad. Sci. USA 94, 5308–5313. Oxenkrug, G.F., 1979. The content and uptake of 5-HT by blood platelets in depressive patients. J. Neural Transm. 45, 285–289. ´ M., Muck-Seler, ¨ ˇ ´ Z., 1997a. Pivac, N., Jakovljevic, D., Brzovic, Hypothalamic–pituitary–adrenal axis function and platelet serotonin concentrations in depressed patients. Psychiatry Res. 73, 123–132. ¨ ˇ ´ M., 1997b. Platelet 5-HT Pivac, N., Muck-Seler, D., Jakovljevic, levels and hypothalamic–pituitary–adrenal axis in schizophrenic patients with positive and negative symptoms. Neuropsychobiology 36, 19–21. Shalev, A.Y., 2000. Posttraumatic stress disorder: diagnosis, history and life course. In: Nutt, D., Davidson, J.R.T., Zohar, J. (Eds.), Posttraumatic Stress Disorder: Diagnosis, Management and Treatment. Martin Dunitz, London, pp. 1–15.
179
Simansky, K.J., 1995. Serotoninergic control of the organization of feeding and satiety. Behav. Brain Res. 73, 37–42. Southwick, S.M., Krystal, J.H., Morgan, A., Johnson, D., Nagy, L., Nicolaou, A., Heninger, G.R., Charney, D.S., 1993. Abnormal noradrenergic function in posttraumatic stress disorder. Arch. Gen. Psychiatry 50, 266–274. Spivak, B., Vered, Y., Graff, E., Blum, I., Mester, R., Weizman, A., 1999. Low platelet poor plasma concentrations of serotonin in patients with combat-related posttraumatic stress disorder. Biol. Psychiatry 45, 840–845. Spivak, B., Segal, M., Laufer, N., Mester, R., Weizman, A., 2000. Lifetime psychiatric comorbidity rate in Israeli non-help-seeking patients with combat-related post-traumatic stress disorder. J. Affect. Disord. 57, 185–188. Stahl, S.M., 1985. Platelets as pharmacological models for the receptors and biochemistry of monoaminergic neurons. In: Longenecker, G.L. (Ed.), Platelets: Physiology and Pharmacology. Academic Press, New York, pp. 307–340. Stahl, S.M., 1998. Mechanism of action of serotonin selective reuptake inhibitors. Serotonin receptors and pathways mediate therapeutic effects and side effects. J. Affect. Disord. 51, 215–235. Weizman, R., Laor, N., Schujovitsky, A., Wolmer, L., Abramovitz-Schnaider, P., Freudstein-Dan, A., Rehavi, M., 1996. Platelet imipramine binding in patients with posttraumatic stress disorder before and after phenelzine treatment. Psychiatry Res. 63, 143–150. Yehuda, R., 2000. Neuroendocrinology. In: Nutt, D., Davidson, J.R.T., Zohar, J. (Eds.), Posttraumatic Stress Disorder: Diagnosis, Management and Treatment. Martin Dunitz, London, pp. 53–67.