We studied reported withdrawal symptoms in a retrospective chart review of 352 patients treated in an outpatient clinic with the nonselective serotonin reuptake inhibitor clomipramine or with one of the selective serotonin reuptake inhibitors (SSRIs), fluoxetine, fluvoxamine, paroxetine, or sertraline. In 171 patients who were supervised during medication tapering and discontinuation, the most common symptoms were dizziness, lethargy, paresthesia, nausea, vivid dreams, irritability, and lowered mood. When patients with at least one qualitatively new symptom were defined as cases, these symptoms occurred significantly more frequently in patients who had been treated either with one of the shorter half-life SSRIs, fluvoxamine or paroxetine (17.2%), or with clomipramine (30.8%), than in patients taking one of the SSRIs with longer half-life metabolites, sertraline or fluoxetine (1.5%). The rate was not significantly different between the different shorter half-life treatments. Cases treated with fluvoxamine or paroxetine had received a significantly longer period of treatment (median 28 weeks) than noncases (16 weeks), but there were no significant associations with age or with diagnostic grouping. There was a trend toward an association with male sex. The majority of cases occurred despite slowly tapered withdrawal. Symptoms persisted for up to 21 days (mean = 11.8 days) after onset. These symptoms were relieved within 24 hours by restarting the medication, but were not relieved by benzodiazepines or by moclobemide. A role has been suggested for serotonin in coordinating sensory and autonomic function with motor activity. We suggest that this may lead to useful hypotheses about the pathophysiology of withdrawal symptoms from serotonin reuptake inhibitors.

Jitteriness/anxiety syndrome remains poorly characterised. Despite this, clinicians' perception of this syndrome influences prescribing and it is cited to support postulated mechanisms of drug action. We recommend systematised evaluation of side-effects at earlier time points in antidepressant trials to further elucidate this clinically important syndrome.

BackgroundThere is concern over the potential impact of the Internet on self-harm and suicidal behaviour, particularly in young people. However, little is known about the prevalence and patterns of suicide/self-harm related Internet use in the general population.MethodsCross sectional study of 3946 of the 8525 participants in the Avon Longitudinal Study of Parents and Children (ALSPAC) who were sent a self-report questionnaire including questions on suicide/self-harm related Internet use and self-harm history at age 21 years.ResultsSuicide/self-harm related Internet use was reported by 22.5% (886/3946) of participants; 11.9% (470/3946) had come across sites/chatrooms discussing self-harm or suicide, 8.2% (323/3946) had searched for information about self-harm, 7.5% (296/3946) had searched for information about suicide and 9.1% (357/3946) had used the Internet to discuss self-harm or suicidal feelings. Suicide/self-harm related Internet use was particularly prevalent amongst those who had harmed with suicidal intent (70%, 174/248), and was strongly associated with the presence of suicidal thoughts, suicidal plans, and history of self-harm. Sites offering help, advice, or support were accessed by a larger proportion of the sample (8.2%, 323/3946) than sites offering information on how to hurt or kill yourself (3.1%, 123/3946). Most individuals (81%) who had accessed these potentially harmful sites had also accessed help sites.Limitations(i) There were differences between questionnaire responders and non-responders which could lead to selection bias and (ii) the data were cross-sectional, and we cannot conclude that associations are causal.ConclusionsSuicide/self-harm related Internet use is common amongst young adults, particularly amongst those with suicidal thoughts and behaviour. Both harmful and helpful sites were accessed, highlighting that the Internet presents potential risks but also offers opportunities for suicide prevention.

The inhalation of 7.5% carbon dioxide (CO2) in healthy subjects produces an increase in blood pressure and heart rate, and increased feelings of anxiety, fear and tension (Bailey et al. 2005). As this state is similar to that of general anxiety rather than panic, we further validated this by examining the effects of anxiolytic medication. Two separate studies in healthy volunteers are described; study one is a double-blind, placebo-controlled study of a single dose of 2 mg lorazepam and study two describes the effects of 21 days of treatment with paroxetine. Gas challenges were air and 7.5% CO2 inhaled for 20 minutes, delivered on day 0 (before treatment) and day 21 (after treatment) in the paroxetine study. Subjective effects were measured using visual analogue scales and questionnaires. When compared with placebo, lorazepam 2 mg significantly reduced peak CO2-induced subjective fear, feelings of wanting to leave, tension and worry. In the paroxetine study, when compared with day 0, day 21 showed a significantly attenuated peak CO2-induced nervousness and a trend for reduced ratings of anxiety, fear, feel like leaving, tense and worried. In these studies we have shown that this CO2 model of anxiety is sensitive to lorazepam and to a lesser extent paroxetine. This gives support to its utility as an experimental model of general anxiety disorder in healthy volunteers.