Schizophrenia typically begins in young adulthood and may lead to disability that lasts a lifetime. The onset of psychosis is usually preceded by a period of non-psychotic symptoms, known as prodromal symptoms. The symptoms of full-blown schizophrenia include hallucinations, delusions, disordered thinking and emotional withdrawal. There is some evidence that a delay in receiving adequate treatment reduces the chances or the extent of recovery.
In broad terms, early intervention has two objectives: the first is to prevent the onset of schizophrenia in people with prodromal symptoms; the second is to provide effective treatment to people in the early stages of schizophrenia, with the goal of reducing the ultimate severity of the illness. Early intervention services are now widespread in America, Europe and Australia.
We sought to review all trials that involved early intervention for people with prodromal symptoms, or a first episode of psychosis. We identified 18 studies, most were underpowered and at present we have insufficient data to draw any definitive conclusions, although further trials are expected.
There is emerging, but as yet inconclusive evidence, to suggest that people in the prodrome of psychosis can be helped by some interventions. There is some support for specialised early intervention services, but further trials would be desirable, and there is a question of whether gains are maintained. There is some support for phase-specific treatment focused on employment and family therapy, but again, this needs replicating with larger and longer trials.
Proponents of early intervention have argued that outcomes might be improved if more therapeutic efforts were focused on the early stages of schizophrenia or on people with prodromal symptoms. Early intervention in schizophrenia has two elements that are distinct from standard care: early detection, and phase-specific treatment (phase-specific treatment is a psychological, social or physical treatment developed, or modified, specifically for use with people at an early stage of the illness).
Early detection and phase-specific treatment may both be offered as supplements to standard care, or may be provided through a specialised early intervention team. Early intervention is now well established as a therapeutic approach in America, Europe and Australasia.
To evaluate the effects of: (a) early detection; (b) phase-specific treatments; and (c) specialised early intervention teams in the treatment of people with prodromal symptoms or first-episode psychosis.
We searched the Cochrane Schizophrenia Group Trials Register (March 2009), inspected reference lists of all identified trials and reviews and contacted experts in the field.
We included all randomised controlled trials (RCTs) designed to prevent progression to psychosis in people showing prodromal symptoms, or to improve outcome for people with first-episode psychosis. Eligible interventions, alone and in combination, included: early detection, phase-specific treatments, and care from specialised early intervention teams. We accepted cluster-randomised trials but excluded non-randomised trials.
We reliably selected studies, quality rated them and extracted data. For dichotomous data, we estimated relative risks (RR), with the 95% confidence intervals (CI). Where possible, we calculated the number needed to treat/harm statistic (NNT/H) and used intention-to-treat analysis (ITT).
Studies were diverse, mostly small, undertaken by pioneering researchers and with many methodological limitations (18 RCTs, total n=1808). Mostly, meta-analyses were inappropriate. For the six studies addressing prevention of psychosis for people with prodromal symptoms, olanzapine seemed of little benefit (n=60, 1 RCT, RR conversion to psychosis 0.58 CI 0.3 to 1.2), and cognitive behavioural therapy (CBT) equally so (n=60, 1 RCT, RR conversion to psychosis 0.50 CI 0.2 to 1.7). A risperidone plus CBT plus specialised team did have benefit over specialist team alone at six months (n=59, 1 RCT, RR conversion to psychosis 0.27 CI 0.1 to 0.9, NNT 4 CI 2 to 20), but this was not seen by 12 months (n=59, 1 RCT, RR 0.54 CI 0.2 to 1.3). Omega 3 fatty acids (EPA) had advantage over placebo (n=76, 1 RCT, RR transition to psychosis 0.13 CI 0.02 to 1.0, NNT 6 CI 5 to 96). We know of no replications of this finding.
The remaining trials aimed to improve outcome in first-episode psychosis. Phase-specific CBT for suicidality seemed to have little effect, but the single study was small (n=56, 1 RCT, RR suicide 0.81 CI 0.05 to 12.26). Family therapy plus a specialised team in the Netherlands did not clearly affect relapse (n=76, RR 1.05 CI 0.4 to 3.0), but without the specialised team in China it may (n=83, 1 RCT, RR admitted to hospital 0.28 CI 0.1 to 0.6, NNT 3 CI 2 to 6). The largest and highest quality study compared specialised team with standard care. Leaving the study early was reduced (n=547, 1 RCT, RR 0.59 CI 0.4 to 0.8, NNT 9 CI 6 to 18) and compliance with treatment improved (n=507, RR stopped treatment 0.20 CI 0.1 to 0.4, NNT 9 CI 8 to 12). The mean number of days spent in hospital at one year were not significantly different (n=507, WMD, -1.39 CI -2.8 to 0.1), neither were data for 'Not hospitalised' by five years (n=547, RR 1.05 CI 0.90 to 1.2). There were no significant differences in numbers 'not living independently' by one year (n=507, RR 0.55 CI 0.3 to 1.2). At five years significantly fewer participants in the treatment group were 'not living independently' (n=547, RR 0.42 CI 0.21 to 0.8, NNT 19 CI 14 to 62). When phase-specific treatment (CBT) was compared with befriending no significant differences emerged in the number of participants being hospitalised over the 12 months (n=62, 1 RCT, RR 1.08 CI 0.59 to 1.99).
Phase-specific treatment E-EPA oils suggested no benefit (n=80, 1 RCT, RR no response 0.90 CI 0.6 to 1.4) as did phase-specific treatment brief intervention (n=106, 1 RCT, RR admission 0.86 CI 0.4 to 1.7). Phase-specific ACE found no benefit but participants given vocational intervention were more likely to be employed (n=41, 1 RCT, RR 0.39 CI 0.21 to 0.7, NNT 2 CI 2 to 4). Phase-specific cannabis and psychosis therapy did not show benefit (n=47, RR cannabis use 1.30 CI 0.8 to 2.2) and crisis assessment did not reduce hospitalisation (n=98, RR 0.85 CI 0.6 to 1.3). Weight was unaffected by early behavioural intervention.