Table 1.
Summary of previous studies that have examined effects of age on psychotic symptom severity. The table is broken down into A) studies that examine participants across the phase of illness, B) studies that focus on first episode psychosis, C) studies of help-seeking adolescents, and D) population sample studies. Other than Pencer et al. (2005), all studies are cross-sectional in nature. All studies of participants with diagnosed with a psychotic disorder include individuals who are currently or previously have been prescribed antipsychotic medication.
| Author and year | Sample size (N) | Age range or mean & type of analysis (group vs. continuous) | Dependent variables examined | Results |
|---|---|---|---|---|
| A. Studies of psychotic disorder across multiple phases of the illness | ||||
| Mueser et al., (1990) | 117 | Age range: 20–58 yrs; Group: those who endorsed hallucinations vs. those who did not |
Responses to auditory, tactile, visual, and olfactory/gustatory hallucination items on SCID-DSM III (Spitzer & Williams, 1985) | Those who endorsed auditory hallucinations had an earlier age of hospitalization vs. those who did not endorse auditory hallucinations. |
| Haas & Sweeney, (1992) | 71 | 18–55 yrs; Continuous |
Total symptom scores from SAPS and SANS (Andreasen 1984a, 1984b) | No significant effects of age on total positive or negative symptom severity. |
| Sharma et al., (1999) | 160 | Age range not reported. Mean age: 32.3 yrs +/−8 yrs; Continuous |
Hallucinations item score from BPRS (Overall 1962) | No significant effect of age or age of onset on hallucination severity. |
| B. Studies of first episode psychosis | ||||
| Hafner et al., (1992) | 276 | 12–59 yrs; Group: 12–24 yrs (N=90) vs. 25–34 yrs (N=110) vs. 35–59 yrs (N=76) |
Individual positive and negative symptom items measured via a semi-structured interview (Hafner et al., 1992) | Increased delusions of reference in 35–39 yrs vs. 12–24 yrs. Increased delusions of persecution in 25–34 yrs vs. 12–24 yrs. |
| Ballageer et al., (2005) | 201 | 15–30 yrs; Group: 15–18 yrs (N=82) vs. 19–30 yrs (N=119) |
Individual item scores from SAPS and SANS (Andreasen 1984a, 1984b) | Increased affective flattening in the younger (15–18 yrs) vs. older group (19–30 yrs). No significant differences between groups for all other measures. |
| Pencer et al., (2005) | 138 (1–3 visits) |
Group: Adolescents: 15–19 yrs (N=69) Adults: 26–50 yrs (N=69) | Total Positive and Negative symptom scores from the PANSS (Kay et al., 1987) | No significant effect of group at baseline, or 1- or 2-yr follow-up. Younger people showed more prominent negative symptoms at baseline. |
| White et al., (2006) | 188 | Group: 12–19 yrs (N=49) vs. 20–39 yrs (N=139) | Total score for SAPS (Andreasen 1984a, 1984b) | No significant differences in total positive and negative symptom scores between age groups. |
| Joa et al., (2009) | 232 | Age range: 15–65 yrs; Group: ≤18 yrs (N=43) vs. >18 yrs (N=189) | Total Positive and Negative symptom scores from the PANSS (Kay et al., 1987) | No significant differences in total positive and negative symptom scores between age groups. |
| C. Studies of help-seeking adolescents | ||||
| Brandizzi et al., (2014) | 171 | Age range: 11–18 yrs; Group: 11–12 yrs (N=30), 13–14 yrs (N=52), 15–16 yrs (N=49), 17–18 years (N=40) |
Four factor scores from positive scale of the Prodromal Questionnaire (Loewy 2005): Conceptual Disorganization and Suspiciousness, Perceptual Abnormalities, Bizarre Experiences, and Magical Ideation | Increased perceptual positive symptoms in 11–12 yrs vs. 17–18 yrs Increased non-perceptual positive symptoms (bizarre experiences) in 17–18 yrs vs. 15–16 yrs |
| Schultze-Lutter et al., (2017) | 133 | Age range: 8–40 yrs; Group: 8–12 yrs (N=12), 13–15 yrs (N=30), 16–17 yrs (N=33), 18–19 yrs (N=15), 20–24 yrs (N=30) 25–40 yrs (N=13) |
Perceptual (P4) and non-perceptual abnormality scores (P1+P2+P3+P5) from SIPS (McGlashan 2002) | Increased subthreshold perceptual positive symptoms in 8–12 yrs. vs. all other age groups. No significant differences between groups for non-perceptual sub-threshold positive symptoms. |
| DeVylder et al., (2013) | 65 | Age range: 12–30 yrs; Continuous | Ratings from Positive and Negative symptom items from SIPS (McGlashan, 2002) | No significant effects of age for positive or negative symptom scores. |
| D. Population sample studies | ||||
| Kelleher et al., (2012b) | Studies 1 & 2 = 2243 Studies 3 & 4 = 329 | Age range: 11–16 yrs; Studies 1 & 2: Continuous; Studies 3 & 4: Group: 11–12 yrs (N=212), 13–15 yrs (N=117) |
Studies 1 & 2: Auditory hallucination item from Adolescent Psychotic Symptom Screener (Kelleher 2011) Studies 3 & 4: Responses to K-SADS-PL psychosis questions (Kaufman et al. 1996) |
Studies 1 & 2: Decreased auditory hallucination endorsement with increasing age. Studies 3 & 4: 22.6% of 11–12 yrs endorsed psychotic symptoms vs. 7% of 13–15 yrs. |
| Schimmelmann et al., (2015) | 689 | Age range: 8–40 yrs; Group: 8–12 yrs (N=45), 13–15 yrs (N=31), 16–17 yrs (N=78), 18–19 yrs (N=81), 20–24 yrs (N=155), 25–29 yrs (N=144), 30–40 yrs (N=155) |
Perceptual (P4) and non-perceptual abnormality scores (P1+P2+P3+P5) from SIPS (McGlashan 2002) | Increased perceptual positive symptom experiences in 8–12 yrs and 13–15 yrs vs. all other age groups. No significant differences between groups for non-perceptual positive experiences. |
Abbreviations: yrs.: years; SCID-DSMII= Structured Clinical Interview for the DSM-III; SAPS=Scale for the Assessment of Positive Symptoms; SANS=Scale for the Assessment of Negative Symptoms; BPRS=Brief Psychiatric Rating Scale; PANSS=Positive and Negative Syndrome Scale; SIPS=Structured Interview for Prodromal Syndromes; P1=unusual thoughts rating on SIPS; P2=suspiciousness rating on SIPS; P3=grandiosity rating on SIPS; P4=perceptual abnormality rating on SIPS; P5=disorganized communication on SIPS; KSADS-PL=Kiddie Schedule for Affective Disorders and Schizophrenia, Present and Lifetime version.