Table 1.

Clinicians’ demographic and professional characteristics (n = 55).

Information	Categories	Sub-categories present	Number of participants per sub-category	Percentage (%) of participants per sub-category
Demographics	Age	18–24 years	1	1.8
		25–39 years	36	65.5
		40–60 years	12	21.8
		60 + years	2	3.6
	Gender	Female	40	72.7
		Male	11	20.0
Primary role service	Sector	Public	43	78.2
		Private	5	9.1
		Both sectors	1	1.8
		Third sector	1	1.8
	Age group worked with	Children/adolescents	36	65.5
		Adults of a working age	26	47.3
		Older adults	10	18.2
		Multiple	16	29.1
	Primary Service type	Specialist*	19	34.5
		Non-specialist	31	56.4
Role	Voluntary	No	51	92.7
	Profession	Clinical psychologist*A	19	35.0
		Trainee Clinical Psychologist	14	25.5
		Psychiatrist	4	7.3
		Trainee Psychiatrist	2	3.6
		Assistant Psychologist	2	3.6
		CBT therapist	2	3.6
		Graduate practitioner*B	2	3.6
		Mental health nurse*C	2	3.6
		Other*D	4	7.3
	When present role started	5 + years ago	17	30.9
		Less than 5 years	20	36.4
		Less than a year ago	8	14.5
		Since lockdown started	6	10.9
	Duration per week in role	2–34 h (i.e. part-time)	19	35.0
		35 + hours (i.e. full time)	30	55.0
Mental health intervention(s) delivered	Type of intervention delivered	Psychological	41	74.5
		Pharmacological	6	10.9
		Psychosocial	3	5.5
		Psychoeducational	1	1.8
	Precise intervention delivered	CBT (including adapted)	25	45.5
		Systemic	8	14.5
		Other (e.g. counselling, eye movement desensitisation therapy, and schema therapy).	7	13.0
		Psychoeducation	5	9.1
		Acceptance and Commitment therapy	5	9.1
		Compassion-Focused therapy	5	9.1
		Medication review	4	7.3
		Behavioural interventions (e.g. Positive Behaviour Support)	4	7.3
		Dialectical behavioural therapy	3	5.5
		Narrative	2	3.6
		Multiple types	22	40.0
	Target of interventions	Anxiety (including social anxiety, generalised anxiety disorder, obsessive compulsive disorder, health anxiety, post-traumatic stress disorder, and vomit phobia)	21	38.2
		Depression or low mood	12	21.8
		Other*E	12	21.8
		Transdiagnostic	9	16.4
		Emotional regulation or literacy	9	16.4
		Multiple targets specified	21	38.2
ASD-specific clinical experience	Specialist ASD service	Yes	28	50.9
		No	22	40.0
	Years working with autistic service-users	Less than a year	7	12.7
		1–9 years	26	47.3
		10–19 years	11	20.0
		20 + years	8	15.0
	Number of autistic service-users worked with	2–10	7	12.7
		11–20	3	5.5
		21–49	10	18.2
		50 +	30	54.5
General clinical experience	Years working in mental health services	Less than a year	0	0
		1–9 years	33	60.0
		10–19 years	9	16.4
		20 + years	9	16.4
	Number of non-autistic service-users worked with	1	1	1.8
		2–10	18	32.7
		11–20	8	14.5
		21–49	7	12.7
		50 +	20	36.4

^{Notes. The proportions presented are those of completers only, and non-responses per category varied between 1.8% and 10.9% (i.e. 1–6 participants) due to either skipping the questionnaire or skipping the questions (all items except those in the inferential statistics optional to reduce participant burden). Intervention sub-categories are not mutually exclusive. Percentages rounded to 1d.p. *Provided in}Supplementary File 5^{. *A. 1 x clinical neuropsychologist. *B. mental health practitioner and psychological wellbeing practitioner. *C. 1 x mental health nurse was also a trainee CBT therapist. *D. Counselling Psychologist, Educational Psychologist, Occupational therapist, and Speech and language therapist. *E i.e. agitation/anger, adjustment, behavioural management and activation, assertiveness, psychoeducation, integrative, mood, perfectionism.}